Raptor: Revolution or Failure?

[@rogerolander458]

Fortunately the Raptor died in a Nebraska corn field this week - Peter walked away safe and sound. Turns out that he has already begun to design a boxed wing concept and is planning on moving forward with that new complex design. Apparently he hasn't learned much about his own design capabilities from the Raptor experiment.

[@noelwade]

But its going to have a hybrid electric propulsion system! Surely that'll be easier and less-complex than a turbodiesel with a PSRU - right? RIGHT??? :-D :-D :-D

[@rogerolander458]

@@noelwade I'm not saying that an experienced team of engineers couldn't design and develop the Raptor NG, but the point is his lack of expertise. The box wing is not an easy, well know design, nor is the duct fan or hybrid electric propulsion system. So once again his lone ranger hubris will undoubtedly get him in over his head. (Like Sheldon, I'm not good at recognising sarcasm. LOL)

[@Mrcaffinebean]

Yeah the audacity of the new design is pretty amazing. After ditching into a corn field I would think the obvious conclusion would have been to go with a proven power plane. I suppose he at least learned that pressurization is a waste of wait.

[@noelwade]

@@rogerolander458 - You may not say that, but *I* will say that an experienced team of engineers couldn't design and develop the Raptor NG. Or rather, that they never _would_ try to do so. The design is _massively_ aerodynamically inefficient in several ways! I started to enumerate them here but it won't fit within the character limits of comments :-P :-D Here are a couple of the highlights (lowlights) of that NG layout: 1) The top-of-wing mount of the ducted fans creates extra interference drag where the shrouds meet the wings. The acute angle between these surfaces will exacerbate the drag and airflow separation (compare that to any decent wing-root fairing that makes these intersections into gently curving obtuse angles). Additionally, the rapid widening of the gap between the rear fuselage sides and the ducted fans *and* the downard sloping angle of the aft part of the wing airfoil in this area will create additional airflow separation and a low-pressure zone that will add noticeably to the overall drag. 2) The lower wing will be contributing very little to the overall lift of the vehicle. That's because the rear part of the airfoil where the fans sit is disrupted by the fan itself. Add to that all of the areas around the fans that will experience airflow separation (see point #1), and you wind up with a very small effective wing area. Essentially that lower wing is just structure that supports the fans and outboard vertical stabilizers - it adds frontal area and wetted area which contribute to the overall drag of the vehicle without doing much else. 3) The vertical fins are just chopped straight some distance below the bottom of the lower wing. No effort has been made to shape them as you would want to (i.e. a "split winglet"). While this lower section of the fin may help reduce the wingtip vortex and add to ground-effect when just above the runway surface, the lack of shaping (taper, twist, sweep, etc) means that this is again going to have a smaller effect than it could while simultaneously being heavier and draggier than necessary. 4) The entire design of the upper wing is completely stupid from a structures standpoint, and nigh-unworkable. Remember that the wing, when flying, will be producing lift and pulling up on the structure. And the greatest concentration of structural load from that lift tends to happen near the middle of the wingspan. Now think about the bending loads on the wing when flying - whole center part of the span has no support (compared to most box-wing designs where the upper or rear wing connects to the fuselage at the center of the span)! The only way to make this upper wing rigid is to create an INCREDIBLY beefy wing-spar; which means a huge amount of weight. That weight must then be carried by the vertical fins; which themselves must now be incredibly beefy (to resist bending loads or side loads. Imagine a big rudder slip or sideways gust of air on those things, with all the weight of the upper wing being borne by the upper tip of the fin. The corners of the fin, where it meets the upper and lower wings, will have to be incredibly strong to help resist "paralellogramming" when there is a side-load applied at the upper or lower wing joint area). And beefy wingtips means making the lower wing spar *also* beefy, since the outboard sections of the lower wing are now going to be asked to carry huge bending loads (downward, due to gravity and the weight of the upper wing when the plane is at rest; as well as upward when flying and the wing is producing lift)! Footnote/Qualifications: I am a pilot with over 1,000 hours in Sailplanes (which use composite structures and have to deal with bending loads on wings more than most airplanes), and I've build my own (propeller-driven) airplane out of aluminum.

[@rogerolander458]

@@noelwade Hi Noel, nice analysis. But in my defense I must say that I assumed my mythical bunch of engineers of diverse disciplines would have addressed the issues you raise. And admittedly, I hadn't given the Raptor NG design any serious thought but while the interference drag issues, etc. had escaped me, I did wonder about the structural loads.

[@mci102rv7]

My favorite saying: “Anything is simple, as long as you don’t understand it.” Applies perfectly here. Great job! On top of everything you listed, on rotations, the prop looks dangerously close to a prop strike.

[@troygleeson738]

ouch. That was like watching someone club a baby seal. Sadly, all true. Thank you for your reasoned clarity. I have found your cooling and turbo research especially helpful.

[@bobstovall5449]

More like putting down a gravely wounded and suffering animal and relieving it of its suffering. The 'Raptor' already exists, as pointed out by 'rf6ejguy'; It's call Velocity and is designed and built by a team of professionals with a fleet of aircraft and a large community of owner/builder/pilots.

[@troygleeson738]

@@bobstovall5449 also True. I think the biggest criticism people have had here is that there was a disconnect between his perception of the task and the actual enormity of the task, which is why he made so many bold claims at the beginning. As RV6 guy stated, he chose not to simplify. he chose absolutely the most complex type of aircraft he could and ended up with a complex monstrosity. It is a classic case of linear thinking in design, leading to an additive, rather than integrated and efficient end result. None the less, the man built a functioning airplane and flew it successfully. From nothing. Essentially alone. I honor him for that.Aviation needs people who do this. I am not excusing his over-estimation of his skills, but he is smart, is learning, and he can refine it. There is 20-30 kts of just aero clean up that is low priority for him at the moment, but as RV6 guy stated, it will take years and possibly another full build to get all of it fixed, and in the end, yes, he will have something comparable to a very wide, possibly pressurized velocity. I just hope he doesn't hurt himself in the process. " all great adventures begin by first grossly underestimating the enormity of the task"-Anon.

[@silasmarner7586]

@@troygleeson738 cough cough! Doug Jackson .. cough cough! SV Seeker

[@jwboll]

As an air conditioning technician, who also has built and flown many planes from kits over the years, I always got a good chuckle out of how much emphasis was placed on the Raptor's most important feature, the air conditioner.

[@AaronCederberg]

I know very little about aeronautical engineering, but I do (unfortunately) know a thing or two about suffering the consequences of getting cocky about aviation and getting in over my head without and/or despite the advice of far more experienced aviators who have a proven track record of wisdom and safety. Watching Peter blow off Wasabi Aviation’s obviously intelligent and well-tested guidance, and proceed with test flights solo, kinda made the six inch rods of titanium in my back tingle… I’ve been following the Raptor project for a few years just because it was cool to watch someone doggedly pursue a dream and document the process of building something, but it became increasingly clear that the dude just doesn’t have the right attitude to be doing what he’s doing.

[@aviator267]

I’ve watched all Raptor project videos. Watched your first video on the turbos and thought to myself that you know a thing or two... after watching this follow up... I’m a subscriber.

[@zmanmd1641]

Peter reminds me of myself doing my first car engine rebuild as a teenager. I didn't know what I didn't know, so I assumed it was way easier than it was. Long story short, I made a mess of it and had to sell it off at a huge loss.

[@deanhowell6730]

But The love that someone will try

[@dangryder6050]

Thank you for analysis. It was very thorough. Raptor has many problem - I have long been banned from commenting on his videos. Even Peter Sripol puts sandbags on the wings of his foam ultralights before he flies them.

[@105blwalker]

Beautiful, if sad, commentary. I built N36LV and tried many times to get Peter’s attention about design issues to no avail. My plane weighed 1950 lbs empty and used a Performance Engines IO-550 with about 370 HP. So it had very similar numbers to Peter’s original goals. At light loading it would climb at 2200+ fpm and could easily exceed its Vne of 200kts at lower altitudes. After watching the Raptor’s first few abysmal takeoff rolls and climb outs, I implored Peter to stop and figure things out. I got banned for my efforts. Sadly, you didn’t even touch much on his absolutely horrendous pilotage and non-existent flight test curriculum. To this day, he still doesn’t have any clue what his best glide speed is and insists on those long, flat finals that will surely end in disaster. I had to stop following his efforts. This airplane will have one guarantee though: it will take Peter to the accident site.

[@ibeapirate123]

So wild to see Peter ignore all best flight test program/engineering practices and barrel head first towards a sure disaster. So much potential behind the idea, and so little belief that doing things right is worth it. Good on you for at least trying to dissuade him

[@tuzisawsome2199]

This guy I like. But is outdated. He's an example of not being able to teach an old dog new tricks... why don't he create a flying car?

[@jonathanhuman7333]

I think Peter can’t get past his ego. He’s worked very hard and invested a lot of money but often it just seems like he’s reinventing the wheel. He’s too blind to see that the plane has already failed.

[@MrMartinglob]

@@tuzisawsome2199 Moller is working on that ;-)

[@tuzisawsome2199]

@@MrMartinglob what with propellers and rotors LMAO

[@satguy]

Since it never met design criteria and now has crashed, I'd say failure.

[@mikehipperson]

I remember halfway through the build, various people including aero engineers were offering advice and guidance but the designer's attitude was "I know what I'm doing and I'll do it my way!"

[@GivenFactNotFiction]

really I wish I could get the free advice from engineers for the many projects I want to do

[@ronkluwe4875]

Ross - Thank you for your calm, well reasoned, analysis of the current state of the Raptor project. Everything you have stated in your video, I have stated to Peter in replies on his videos. Like many others, I had hoped to see Peter succeed, but now realize my hopes are that he doesn't end up killing himself and/or others as the project continues to fumble forward.

[@billrb4855]

Excellent video, clear talk on many of the numerous problems with this project. I was one who initially put a deposit on the airplane years ago, but had mine refunded when it became apparent Peter has no team of experts working with him, but was just the two of them...Peter and his extremely large ego. He received over 2 million to get this far into the project by sending letters to depositors, asking for $20,000 each. In return for their money, they would be moved up the waiting list, get a guaranteed price out the door of $120,000, and get a small percentage of the production company ownership. Unfortunately while the initial deposits like mine are not held by Peter, and are refundable, the $20,000 investments are not. My belief is that Peter will declare bankruptcy and wander off into oblivion, which is probably the best. That, or we will eventually read about the accident that ends it all.

[@rv6ejguy]

Thank you for posting this.

[@Mike-01234]

Wonder why he doesn't use the crowdsourcing online at least those people understand the money is an investment not a prepayment for something not sold yet. StartEnegine was a Crowdfunding website lot of failures there.

[@Tonnsfabrication]

Stopped watching that project a long time ago.Every time I see something about it, I just hope he didn't hurt anyone on the ground with it.

[@Micah1Powell]

I stopped as well. I was just cringing through every video update. Seeing the instability of the plane and the climb rate that is half that of a Piper Warrior, I just hope his untested ballistic recovery system works.

[@Mike-01234]

@@Micah1Powell I think he fixed all that now it's stable last few videos

[@Tonnsfabrication]

Well Its finally over, he did'nt yard dart the thing like I always figured would happen but I'd say that crash ended the project for sure. Thank God it was just some corn taken out and not people's lives.

[@Micah1Powell]

Glad he's OK. Hate to see someone spend that much time and energy on something for it to end that way.

[@e36s50b30]

@@Tonnsfabrication that was by far the best possible outcome for that whole project.

[@DoRC]

I'm definitely no engineer but I am a professional mechanic with quite a few years under my belt and I finally gave up on this project when he refused to actually go through all of the oil systems post engine grenade and make sure they were cleaned or replaced. I imagine it's just a matter of time before the engine he put in there is junk as well due to metal contamination. I just hope that this project ends with the plane gathering dust in a corner and not wadded up in a field somewhere.

[@korova2000]

Very valuable and professional overview of the Raptor project.Thank you for the effort to put all this together.

[@rileyswing9731]

Thank you for the kind words!

[@mccartanaaron]

Budgeting for a kit. Your numbers are amazing! Canard done right...

[@keepyourbilsteins]

You are gracious to see your project undone. Oh wait, this was a shitpost wasn't it.

[@rileyswing9731]

@@keepyourbilsteins what?

[@mccartanaaron]

@@keepyourbilsteins Don't understand that comment. Velocity was complimented in this video and I'm considering buying a project or kit for an XL now that I've finished a Glasair. Can you explain?

[@keepyourbilsteins]

@@rileyswing9731 Sorry, I assumed too much. A shitpost is typically a very sarcastic response. Or a "hot take". Since you've not taken constructive criticism or offers to help on your project with any attitude that resembles humility or gratitude, one can assume that it is not in your nature to admit failure at maximum, or the need to accept input from people that sincerely wish for your project to succeed. No cogent skeptic of your project wishes failure. The entire EA community wants to help you. Buck up. Take the advice from those that have experience. No one wants Raptor to end up a smoking hole that arrives at the scene of the accident first.

[@hechtspeed]

Guy has no clue what hes doing. Its a miracle hes still alive

[@hechtspeed]

Eliot seguin made a excellent choice in dropping this program

[@hechtspeed]

@@adambarber100 ha!!! I personally know elliot. Theres things like safety margin that need to be consodered...especially in the 1st flight of a un proven airframe and power system. There were also other issues off camera. Elliot is a very smart engineer amd designed and built his own formula 1 racer. He also has experience flying tons of dofferemt types of airplanes. He knows what he needs for a safe test program....amd this "program" didnt meet those needs. Nor was the builder willing to work with them on the changes they wanted to be made before first flight. The guy doing the raptor is a lose cannon...and doesnt know shit about power systems..nobody in their right mind...having limoted knoledge would look at the raptor program up to this poikt and say...yeah sign me up..thats going to be awesome..... hed be lucky to live long enough to sell a single airplane.

[@creightonking8436]

@@adambarber100 wow are you uninformed

[@ATECZephyr]

@@adambarber100 You need to go watch Elliot's video on his channel on the raptor. He goes way more into it than what Peter's edited video actually showed.

[@andrewjamez]

@@adambarber100 No, It probably just took Eliot a few runs in the Raptor to realise that this thing aint performing anywhere near close to what Peter told him or showed him on paper...

[@johnlichtenstein6158]

@@adambarber100 I think the airplane inspired so little confidence, that elliots margins to achieve acceptable risk went way up. Had the aircraft performed better, and workmanship been better, I’ll bet they would have stayed at KCNI

[@invertmast]

I only follow the Raptor project for two reasons. 1- its a train wreck waiting to happen 2- Peter is so completely clueless on so many different tasks that it is just mind boggling to watch what kind of failed attempt at a bandaid he will come up with next.

[@markspc1]

Hindsight is always better than foresight. Sower grapes I think.

[@TeemarkConvair]

yes, it IS a train wreck, on the rails still,, the dismissal of a highly qualified test pilot shows where this all is heading, unfortunately.

[@Swarfman64]

Same, its a comical build in a morbid kind of way tho.

[@dmc2554]

I'm still laughing........beautiful comment

[@scsirob]

Peter is working together with his buddies Tee and Ee (Trial and Error). All constructive feedback is ignored. The most important part of his plane appears to be the air conditioning. He can't stop talking about it. I'm afraid this will end up in the local news headlines, and can only hope that he doesn't take any unsuspecting bystanders with him.

[@kbrown9954]

It did. Luckily no one died.

[@i.r.wayright1457]

I was holding my breath on his first test flight video and after seeing how unstable in pitch it was, I figured he was lucky to get it back down in one piece.

[@Chris-bg8mk]

Not just pitch but roll too. And nasty oscillatory coupling. Its scary to watch and he insults anyone who mentions it like a parent with an ugly baby. He blames it on turbulence when any pilot with instincts would say, looks like a relatively smooth day to me.

[@i.r.wayright1457]

@@Chris-bg8mk Sometimes you find people and come away thinking, "This person was educated beyond their intelligence."

[@leoa4c]

@@Chris-bg8mk The turbulence was not the problem. He needs to raise the canards or lower the main wing, or both.

[@yakflyer]

I have followed this from the start. At the beginning I was impressed and thought it was a design worth following. At some point around the time of fitting undercarriage position switches I started to think I might have been wrong, I almost didn't want to believe what my instinct was telling me. From then until now things have got far worse and watching the fixes being implemented has become almost painful viewing. Aviation has learnt it's lessons the hard way over many years, that knowledge is there for the good and safety of people like me. To see these lessons being ignored with an I know better attitude is simply dangerous and disrespectful. I am not an engineer so I will not pass opinion of some of the design madness I feel I have seen. I am a pilot with a few hours gained over many years and have flown aircraft from the very early days through ww2 and up to todays latest designs. As I former instructor I worry for the new pilots who could stumble into ownership of any aircraft that might try its best to ruin their day. My heartfelt wish is to see this project quietly get dropped before anyone is hurt. The designer has my respect for trying to give us something new and for his tenacity in keeping at it. His attitude towards advice is letting him down. He should pay heed to the olds saying 'when you are in a hole it's time to stop digging'. I don't watch anymore.. Thank you for your well presented and very interesting breakdown of some of the issues here. You clearly have very strong feelings but you have done a good job of keeping it professional.

[@wenkeli1409]

The performance claims would be basically unachievable _even_ if the development was properly executed. In this case, the basic execution of the program is so far off the mark it's venturing into the "it's not even wrong" territory. The designer had plenty of knowledgeable people trying to help him. Unfortunately, there is only so much that can be done when the designer doesn't know what he doesn't know, and worse, is not willing to listen or learn. It's actually almost funny to watch the "progress" of this airplane, if not for the potential danger to life and limb of the designer and the potential customers. Tenacity, properly applied, is always to be applauded. Tenacity, without proper direction, without willingness to learn, is just a farce. The only value of this whole engineering exercise is as a case study of what not to do.

[@BIGWIGGLE223]

I couldn't agree more. I had real high hopes of seeing it fly, until I actually watched that terrifying video of it doing something that resembled flying. The way he acted when Wasabi was there really just rubbed me the wrong way. I'm sure a lot of investors and people that put a deposit down backed out as soon as they seen his video of Peters attitude and unwillingness to listen to sound advise.

[@gasdive]

@@BIGWIGGLE223 I watched a lot and put a lot of my "that seems weird" feelings down to not being an expert in any way. But when he said something along the lines of "oh, yeah, circlip to hold on the oil seal, it just seemed like too much trouble to put it on, so I just left it off" The clip that stops the oil seal being blown out and dumping all the oil overboard. Too much trouble. Oh My God.

[@Swarfman64]

@@gasdive Don't forget the hair tie on the door latch

[@ronboe6325]

If this was the '30's or even the '40's he could get away with this build (until it tried to kill him). But today, the standards are higher, the tech is more mature, a commercial market will not accept a amateur effort (even a very good effort). The designers ego and faith in his own intellect - and probably most importantly, lack of proper funding to do this the right way; will prevent a timely successful project.

[@sl66ggehrubt]

Had he approached it incrementally and collaboratively by for example approaching Velocity or an experimental engine builder with a proposal to build a auto conversion engine, he could've maybe gotten the guidance along the way on how to do it properly, and maybe someone would've taken an interest in certifying a conversion kit. The only selling point/revolutionary aspect of his project was the prospect of taking audi crate engines that are abundant and dirt cheap from scrap yards, clamping on a gear box and go fly another 2,000 TBO for a few thousand dollars. The airframe wasn't any better than the current tech (Velocity), nothing new about carbon fiber construction.

[@Kneedragon1962]

I don't want to pick on old mate who is building the Raptor, because he's a flying geek, he loves canard aircraft, he's an (expat) Aussie, and he's doing something I have dreamed of doing for 50+ years. That said, I have watched a number of his videos and come away scratching my head several times. Many, many of the things he's said and done on camera, don't seem to me to add up. The impression I get, is not deliberate deception or attempting to take money off people, it's more that he half knows what he's doing and half doesn't. There's a lot of things I've seen him say and do, that don't seem to me to be right. As in, it doesn't work that way, mate ....

[@simonbaxter8001]

6th Aug 2021 - Was only a matter of time ! NEAR FAIRMONT, Neb. (KSNB) - A pilot from Arkansas walked away after his experimental plane crashed Friday morning in a Nebraska cornfield. Fillmore County Sheriff Bill Burgess said the crash happened around 7 a.m. Burgess said Peter Muller of Clinton, Arkansas told him that his plane lost power while he was trying to fly between Manhattan, Kansas and Grand Island. The plane crashed into a cornfield just north of Highway 6 about four miles west of Fairmont. Burgess said Muller was flying the plane in stages as part of a longer trip from Clinton, Arkansas to Boise, Idaho. He said Fillmore County deputies and Nebraska State troopers found Muller 20-30 minutes after the crash. The pilot was uninjured and there was no property damage other than to the cornfield. Burgess said there was no fire or explosion associated with the crash. The FAA was called in to investigate.

[@avshiloh2438]

As a Mechanical Engineer for more than 40 years, I agree with virtually everything you said. Peter’s project, which I have followed from the beginning, is doomed to failure unless he gets (quite) a few million dollars and a (huge) bunch of professional help. ***BUT*** One must admire Peter for his effort and unbelievable tenacity. This guy faces failures galore, yet remains active. He’s like the Energizer Bunny. I truly admire and respect him for that. I would have called it quits long ago. I also admire his openness and honesty about his successes and failures. My heart is heavy knowing that Peter’s project is doomed. Yet, a tiny spark of (irrational) hope still remains. I will continue to watch his progress and pray for him and his safety.

[@ronkluwe4875]

As an engineer and project manager, I look at putting lots of effort into bad solutions as wasted time and money. You are very on point with your assessment that Peter needs a couple of million dollars and a huge bunch of professional help to turn this project around, but unfortunately that is not going to happen unless the new company Peter is talking about is headed up by someone who can push Peter out of the way. All he has accomplished to perform at this point is to build a bad prototype of a Velocity clone.

[@rv6ejguy]

I commended him for his drive and tenacity as well. That part is amazing. I agree with the rest of your assessment as well here.

[@dmc2554]

@@rv6ejguy ....I'm starting to form the opinion that his "Drive/Tenacity" is ITSELF a barrier to clear(er) thinking.....I'll coin a phrase..."More Balls than Brains".

[@davidlirio1]

His arrogance towards all the very experienced (non IT or software engineers) trying to give advice to help remedy engine and airframe issues in the comments on his videos and Wasabi aka Elliot Senguin shows he isn't interested in actually trying to make Raptor successful. He's actually blocked some of these people some of these people. His personal pride is getting in the way.

[@gmcjetpilot]

You're just making it personal now, nothing intelligent to contribute except bash the guy personally. *He did everything they told him to do that was flight critical.* The Wasabi test pilot was afraid... and kept making excuses. I did not see arrogance on Peter's end. Decisions had to be made... It is like Anthony Fauci telling us to lock down and double mask for another year after you've been vaccinated... There's always going to be risks.. YOUR claims he does not want to make it a success is just you running your mouth. Who did he block? Who? What help was the peanut gallery giving? Who are these internet aircraft experts and what constructive comments were suggested and dismissed? I have made some very critical comments on the Raptor Channel and I haven't been blocked. Keep it facts like this video. The fact is the current prototype is no where near predicted design performance. Short of putting a pt6 on it this aircraft is not going to do what he was hoping it would do.

[@davidlirio1]

@@gmcjetpilot So not having a long enough runway to do an aborted take off or suitable places to put it down in an emergency is being "afraid"? I suggest you watch Elliot's crash of the turbine powered Quickie. The fact that he continues to do testing of new experimental aircraft after a near fatal crash proves he is not "afraid" but has probably increased his personal minimums so as to try not to leave behind a widow and fatherless children. Peter was obviously annoyed and reluctant to do the move to a more suitable airport because of the cost but at least he was smart enough that time to take Elliot's advice and give in. Honestly the move was the right choice with how much runway Raptor currently needs. It will probably save Peter's life one day when the engine or PSRU fails at low altitude. On Elliot's second cross country visit he still wasn't happy and kept his reasoning out of the public eye so as to not bash a customer (bad for future business). Also Peter was insinuating Elliot's price for his services was too much for a real Test Pilot and engineer to travel from California. One comment I remember recently seeing and then no longer existed was someone recommending he physically wear a parachute. Peter responded that the aircraft has an airframe parachute and he doesn't need one. His airframee parachute installation is completely untested. If It fails to properly deploy Peter will no longer exist if he is unable to physically bail out. He's even stopped wearing the fire resistant flightsuit and helmet he wore on his first flight. He's now just wearing shorts and a t-shirt on his flights which has decreased his survivability during an incident that wouldn't be fatal if proper personal protection is worn. Also if he isn't blocking people he's at the very least deleting comments. I suggest you look to see if your negative comments are still visible to everyone by using a different KZbin account because it will still show up on the account you left the comments on. I rarely respond to replies on social media because it just ends up being two people not willing to give in so this will be my last reply.

[@Gearlube_chain_wax_solutions]

I noticed that recently he removes all negative comments

[@simonbaxter8001]

@@davidlirio1 If he hadn't moved to Valdosa (on the advice of Wasabi to find somewhere more suitable), the first flight and 2 subsequent inflight emergencies (latest on 16th April) would have put the Raptor in trees. I agree in that Elliot is not 'afraid' of anything, he just mitigates and/or walks away from the unnecessary risks that stare back at him when he inspects what he's about to put his butt into! Who watched their visit to Raptor to do the inspection and was horrified by the level of design/implementation incompetence. I know I certainly did ... so did Wasabi. For me that was 100% a good call.

[@philpotter6388]

@@gmcjetpilot he blocked me

[@danieldonaldson8634]

Very well reasoned, but I am no expert. What is really striking to me (as an erstwhile software engineer), is that Peter rejects the methodology that we would probably find him using when writing code. What Peter is basically working on is the aviation version of spaghetti code. At some point, you've got to make a choice: know when what you've done is a mess, push it aside. Then, break down what you've learned into components, seek competent individuals and information in those areas, scale back to what can be securely and correctly achieved, develop exhaustive test protocols that isolate and identify individual problems that allow you to isolate they solutions. And don't try to keep saving the crappy spaghetti code. But, maybe he's one of *those* programmers, I dunno....

[@carlwilliams1570]

A 4K lbs canard pusher with an auto engine that has a longer takeoff roll the a loaded B52. It can barely out run a Pacer! Who would want to build one? As Virginia Aviation Hall of Fame member Rucker Tibbs would say “I wouldn’t get out of the electric chair to fly that!”

[@pauljs75]

For all the hype and possible flaws, on the upside the documentation to video of the development is still something to learn from. (Maybe in some ways how not to do things. But as long as it remains public that will still prove useful.) Gives a look into the development process that most people in the field typically keep private.

[@delschier1419]

I own and fly a Cozy IV, four seats, 200 mph cruise @ 6.5 gph, 1500 mi range, with reserve. 1283 # empty 2200 # gross 200 HP IO-360C1E6. Great airplane, I love flying it. The big compromise is it is cozy and I can only use a paved runway of > 3000'. It now has 800 hrs on it and cost about $60 K used.

[@yukon4511]

200 mph at 6.5 gph ????

[@rogerlaubhan7700]

The points made in this video are all good. He only touches on the things wrong with this project. I expect this project to end badly. I've watched this from the start there are so many unairworthy things I would not even want to be around if it was going to fly.

[@Jacmac1]

History proved you correct.

[@gmcjetpilot]

This went from concept to flying prototype. Many paper planes never get this far. With that said the video is correct. I noted all this years ago. As said he should be congratulated for tenacity and getting it flying. Also the early claims can never be met.

[@airtightindustries]

Good comment.

[@SailFlyTri]

That’s a clean kill brother.

[@keepyourbilsteins]

You are an entirely too kind person to take the time to disassemble all that has been the Raptor concept.

[@kimkeam2094]

Thank you for posting this issue, I expressed concern on a couple of items and was shut down very quickly. I tried to make constructive criticism in a friendly manner but obviously it was not accepted. Hopefully he will stop, look at the facts and reevaluate the risks he is taking.

[@Swarfman64]

To most people there are many glaring issues. the question is, is he willfully pushing a non starter for profit of is he unknowingly riding a sinking ship down. Surly after cheating death by literally 1/2 second after the engine failure landing you would stand back and take stock.

[@markmark5269]

So many people, even Raptor Guy's own aerodynamicist and his composite build guys, and of course later, Wasabi, kept telling him the issues, and his narcissism refused to accept that he could possibly be wrong. That's besides the literally hundreds of aircraft industry people, including Ross above, pointing out the issues, throughout 6 years or so of the build. His position on KZbin was to simple delete and block anyone who dared to offer critique, leaving only almost cult like followers, to comment completely ignorantly, in the positive. Now, disgustingly, he is publicly blaming his team members for the failure. Note he hasn't had any team members for a couple of years now, they all walked away from it.

[@aGabay]

Thank you for this video! Sums up everything one needs to know about this project.

[@PeteZoot]

Finally. If i could heart this i would. Thx for spelling out the concerns of the wider (somewhat critical) community. You have done a service for the homebuilder family. Since Viking has sold alot of engines now, I be very interested in your analysis of that product as well which will soon impact(?) the homebuilt flying stats.

[@bh3141]

Look up the history of Viking (Eggenfellner) business practices before making any decisions.

[@PeteZoot]

@@bh3141 don’t i know it lol..... this was a question hopefully to shed light on Viking’s bs marketing, and questionable tech implementation.

[@paulslevinsky580]

Dude. Are you a stalker?

[@PeteZoot]

@@paulslevinsky580 lol. Nope, but they should be covered to to same depth.

[@paulslevinsky580]

@@PeteZoot I remember a guy describing his experience with a Wankel engine conversion "specialist" of the same vintage named Duncan. He was separated from $25 grand in 1990's money. I'm putting a prop on a $300 dollar Honda clone, so I win the smiles per dollar contest.

[@aeroskipper8481]

I bought a place in the queue for a Raptor many years ago. I will not proceed buying the final model. I will stay with my Grand DUKE B60 STC for now - and then maybe look into a Velocity (if I want a single engine) - or even a Citation jet. Flying an aircraft that is proven - by skilled professionals, in all aspects - to work as expected and advertised, is always the best option. (Retired B747-8/400 Commander)

[@rv6ejguy]

A good friend had a $2K deposit on Raptor and thought the specs were too good to be true but since the money was in escrow, if it didn't pan out close enough to his requirements, he could get his money back. Entirely reasonable.

[@silasmarner7586]

The calmer you are, the madder I'm sure Peter gets.. but the criticisms and observations are reasonable as stated.

[@dirkk4992]

hoping Pete gets so mad that he walks away to clear his head, sees the errors of his ways and put a proper plan together to correct the flaws in his prototype and get it airborne.

[@silasmarner7586]

@@dirkk4992 I'd love to see these two guys locked in a room and debate all of this. Mr. Muller would get very angry, turn bright red, and then start crying and gnashing his teeth.

[@tomcoryell]

No static load test is a massive red flag. It is unbelievable to me that he actually flew it without that.

[@kevinturner5685]

Have you taken a look at the development of the Dark Aero Prototype yet? Looks to be a pretty hot aircraft, & appears that they know a good bit about engineering between them.

[@ulbuilder]

I think those brothers are going to make a huge success of their project. Clearly have the requisite knowledge and education.

[@thomaschilcott]

I like to watch DarkAero content immediately after I watch anything about Raptor; the contrast in basic engineering competence soothes my troubled soul hahahahaha!

[@BIGWIGGLE223]

It's completely night and day differences between what they're doing at Dark Aero and what Peter is doing with the Raptor. Dark Aero is doing it right. So far. If I've learned anything from watching Raptor all these years now, it's to not get too sucked into the "projected expectations", but always keep my expectations low.

[@willhibbardii2450]

Dark Aero is also an awesome project. 39.6K Subscribers producing 92 videos. Speaks for it's self. A fast efficient 2 place aircraft with an aircraft propulsion system that's well known in just 2 years of development is very rapid. I'm looking forward to their test flights.

[@willhibbardii2450]

@@BIGWIGGLE223 , My takeaway from both projects is that they are daring to endeavor to produce better than before experimental light aircraft that are affordable, fast and fuel efficient. Dark Aero is working at classical, conventional 2 place machine build with modern carbon fiber composite materials. Still a naturally asperated antique air-cooled petrol engine that TBOs at 1,500 hours. Raptor is a widebody design that is fast and efficient. The takeoff and landing speeds are similar to a small corporate jet. Peter Muller is employing CI diesel propulsion that is very efficient, very clean exhaust emissions with a low fuel flow to horsepower ratio. It will burn Jet-A fuel with additive or diesel. In Africa by necessity of not able to get Jet A or 100 LL fuels in that country we have 20 years history of auto converted CI 3~4 liter piston diesel engines to aviation that statistically are proving reliability to turbine engines with up to 5,000 hours uneventful running hours. Shock cooling is avoided with liquid cooling lowering maintenance cost. The series turbos deliver about 240 HP with about a 12 GPH Fuel Flow at continuous cruise settings. The main point of both builds is employing carbon fiber instead of fiberglass. Both channels are showing the public how to do it to the public. Folks like myself that have been working with more established now certified manufactured aircraft that started this process over 25 years ago simply haven't had time to produce quality video content like these two companies have. We were living under a rock and couldn't see the forest for the trees. Now we are collaborating together to work at building better aircraft. I credit Peter Muller with the Raptor Aircraft project with opening our eyes. He started this conversation as well as Mike Patey. We have the tools to build much better single engine piston aircraft. I love turbine engines but can't afford the fuel flow for transporting myself around in aircraft. Turbo diesels deliver more available horsepower than petrol engines with almost half the fuel flow when configured properly and last much longer with proven dependability. I won't create another company however both Raptor and Dark Aero have motivated me to silently blend and build my own experimental private GA personal aircraft that's built from carbon fiber materials and employs a marine CI diesel series turbocharged engine converted to aviation. Others are doing the same thing in the DIY (Do It Yourself) avoiding corporate manufacturer road blocks. I hope your having fun because we are!

[@Jacmac1]

From the Raptor wiki page: "In an August 2019 video the prototype was weighed at an empty weight of 3,144 lb (1,426 kg), which is 1,344 lb (610 kg) heavier than originally estimated. At a gross weight of 3,800 lb (1,724 kg) the aircraft's useful load is 656 lb (298 kg). With full fuel of 121 U.S. gallons (460 L; 101 imp gal) the payload is −70 lb (−32 kg)" If the useful payload is -70 pounds at full fuel, why would the design even be undergoing further testing? I guess you could say that the airframe could be proved and maybe redesigned based on testing, but it seems like a lot of work for very little payout in the end.

[@rv6ejguy]

The original estimate from 2013 was 1800 pounds, revised in 2018 to 2000 pounds. After weighing in 2019, the aircraft has had ballast, coolant tanks, coolant, extra heat exchangers and plumbing, steel keel plates, control mass balances, a heavier drive coupling and some other smaller bits added, bringing weight up to over 3400 pounds by my estimates, so useful load is closer to 400 pounds- 2 people and an hour of fuel at best. Not a useful 4 place airplane in any way.

[@orbitalair2103]

Reduction drives are probably the single deadliest component in aircraft crashes going back to WW1(SE5a)

[@nicklockard]

Expand on that please? I would like to learn more.

[@BGTech1]

Thanks for this, as an engineering student there are good lessons to be learned from this project.

[@theresacaron4238]

Met many pipe dreamers over the years, flying and non-flying, most of the flying ones that I knew are 6 feet under, the other ones are bankrupt. In all cases they refused anybody's advise or tutelage that was offered as a kind gesture with no strings attached. Unfortunately history repeats itself all the time and in Peter's case, he'll either run out of funds or lives before this comes to an end. It is one thing to think you are infallible if qualified, but he doesn't even come close to that, an accident waiting for a place to happen unfortunately.

[@davegrenier1160]

I am not a pilot nor an engineer of any kind. But I watched two videos about the Raptor and thought the builders were either snake oil salesmen or completely clueless. Now Mike Patey is an airplane-building madman.

[@TreeLBollingTreeMan]

Won't it be wonderful if Mike Patey dropped in and helped on the Raptor. But then again Peter wouldn't listen to Mike. Sad!!!

[@dmc2554]

Agreed.

[@Tenright77]

Thanks for your considered discourse on this design. It is unfortunate so many issues have been allowed to develop.

[@normancole3415]

They didn't really develop they were there from the start Peter is just to hardheaded and sure of himself he doesn't see the problem or really know how to correct them

[@danstein86]

The laws of physics always prevail. It would have been so simple for Peter the designer to simply review the existing designs and performance of existing aircraft. Even at the very least a simple wind tunnel test at a local University would have provided more accurate drag and lift curves. The designer simply had to sit and read a few chapters from one of the many aerodynamics texts, or fluid mechanics texts to see that his claims of aircraft performance were simply not achievable. The Velocity aircraft is one that has been proven in performance for well over a decade. The laws of physics always prevail. Thank you for a direct and succinct analysis of Peter's claims.

[@georgeingram9157]

A quick sanity test is calculate the HP required for the Cirrus to fly with the drag that Peter modelled it as having. Hint, it's engine seems to be exceptionally conservatively rated...

[@hechtspeed]

Failure. That airplane is a mess. The engije install is anyways

[@johntenhave1]

Even experts have failures, but usually we do not get to see them, because the designer is honest enough and aware enough to realise what he is doing will not achieve the aims. This fellow would be very wise to revisit the lessons of history. Even someone as skilled and experienced as Burt Rutan faced similar problems when developing the Vari Eze to it’s final configuration and then the evolution of the Long Ez. Peter needs to realise his solution to the problem he has set himself will not work. it has already been solved far more elegantly by others. A turbine might solve some of his weight issues, but if the structure is an unknown quantity, it needs a back to the drawing board review and revision. This project can most charitably described as a collection of ways not to proceed. He now knows what does not work and it i a very long list.

[@rv6ejguy]

Agreed and those of us who have built lots of stuff have had our failures too. The big difference I see here is he's trying to sell this to other people as some superior game changer.

[@philpotter6388]

Thanks, Ross. As usual, well analyzed and presented.

[@golfmaniac]

I like Peter, but have to agree with you on all points. I really don't see this plane getting into production. A non engineer trying to design something this complex was never going to turn out well. The redrive is one of the weak links in the propulsion system. I would be constantly worried about it failing in flight. Cooling was a joke from the beginning. and now he is having to try to put Band-Aids on it, to get it to 40 hours. If you look at how the plane has performed in testing, you would have to come to the conclusion that it would require a major engineering change to become a trust worthy aircraft.. At this point I do not see why anyone would buy this plane over a proven Velocity.

[@willhibbardii2450]

I've found in navigating the commercial world when a client request a one off production of the most simplistic part/piece/wicket from any material that the first pop is a concept prototype. Most times when producing an original unit I may have an idea of what the part can ultimately transform into however I can't control the application. Carbon fiber and composites plug/mold production has been a focus of mine since 1969 in the marine industry. Working with the folks that have made a decision that what's out there in the mainstream off the shelf markets doesn't meet their needs, wants or desires is custom crafting. Spending time with folks that lay in bed at night thinking up what they want then drawing a model is metaphysical work. Those that dare to transition from metaphysical labor to physical production isn't pipe dreaming. One of my favorite quotes: "Thinking is the hardest job on the planet! That's why so few participate in it." Private 4~5 place general aviation aviators today have many problems to solve that hasn't been solved by the commercial world. My hats off to the men that dare to think and produce. It takes many folks to produce an ultimate platform. The problem is that the men that had original ideas and produced their metaphysical works into something for others to enjoy have vanished through the revolving door. The new leaders are dreaming and producing what they want... If your happy with your creation then my hats of to you. Congratulations! I still have many things to produce for myself and others... Cheers

[@willhibbardii2450]

@@ryanthomas2472 , I'm scheduled to work on two Lake Aircraft this week. One of the guys that owns one of them is an airline pilot. He has a deposit on a Raptor. Good idea... We may discuss that Wednesday while working. Thank you. Lakes have turbo charged engines you know. I'm not trying to be funny. Good idea! Cheers

[@willhibbardii2450]

@@ryanthomas2472 , We probably could have contributed to the Raptor project if we would have been aware of it at that time. I wasn't made aware of his fine work till June of 2020. I was looking for a all composite start-up aircraft company that had already produced the female production molds for my 135 KW hybrid electric aircraft propulsion system. I employ lofting to fabricate plugs for production molds. I've had the privilege to plug for other's their ideas, some drawn up on napkins over the years. I've found that once we fabricate a concept prototype to full size intent and application. We then can balance the composites for price-point, supply-chain, workmanship, support, strength, weight, reliability, quantity of materials needed and make adjustments for performance on the production prototype. The key to our success is that while we are testing the production prototypes in real-world application we are also testing the 2 foot models gleaning the fluid dynamics of what it is we are spending time to achieve. We then add the features that make the 2 foot model more efficient to the production prototype for further testing. To me testing the production prototype is the most fun. After the final production prototype is molded for production another idea comes along and we keep moving forward. I've never heard of an experimental boat however I've been testing different powerplants that have aviation capabilities for years. I've never talked to Peter Muller and he has not responded to my offers to work with him to produce high quality carbon fiber and composite parts for Raptor as we do for other FAA certified aircraft manufactures. That being said I'm thankful for his efforts to make and produce his Private Experimental Aircraft. I have a family member that is large and heavy that loves to fly little aircraft. She isn't comfortable flying a 182. With refinement the Raptor type aircraft would work for her. So you see what some call a bad idea may be the perfect solution for someone else's needs. I wouldn't have used his business model to undertake such a project however the folks that have the excess funds to support the project have opened my mind that Experimental Aircraft is the path. Serious conversations are happening in the aviation world. The Raptor project has set targets and goals to achieve that are tough. If it were easy everyone would do it. Laminar flow winged canard watercraft that happens to fly and land on an airstrip or load on a trailer may be a solution. I'm sure someone will try it. I've found if we can think it, over time we can produce it. It takes persistence, tenacity, desire, time, fun, community interest/involvement, experience and luck. The naysayers with their lack just settle. Yesterday I landed at Franklin County Airport in Texas. The transmission power company are constructing the towers for the new infrastructure. I was privileged to see an incredible helicopter that drinks Jet A at 550 Gallons of fuel per hour. This aircraft is rated to lift 20,000 pounds and also serves for fighting forest fires. It has a front pilot and a rear pilot, copilot and flight engineer. It's outfitted with 4 each 400 gallon fuel tanks facilitating 2 hours of flight time. The air-crane is a CH-54E. Because of the fuel flow 2 tanker trucks must be on site to keep this bird flying and traveling ahead on cross country flights. I know the turbine engines well that provides the propulsion as well as the APS that starts it. Turbines have their place however the fuel flow isn't affordable to facilitate light aircraft or the price tag of operations. I've been silently working on that solution testing with boats. I've been employing aircraft construction methods in producing yachts since 2008. We have independent teams of folks in place that produce the best composites, CNC production here in DFW for aerospace that have been actively working for producing their dreams concerning light aircraft to rockets. Looks to me like more fun times ahead spending quality times with folks perusing their various passions of transforming ideas into reality in the composites world and piston propulsion. No one person has all the answers however addressing concerns is paramount. Turbocharging CI Diesel Engines and cooling with little drag is tough for light aircraft operations however in my humble experienced opinion, series compounding to produce about 240 horsepower for operations at FL-24 employing the 3L V-6 aluminum engine with a target of 12 GPH fuel flow is a doable target. I'm pursuing this myself and for myself. But silently... I like the reserve power that this configuration offers that the Continental air-cooled petrol fueled engines cant offer at about the same weight... I hope your having fun because we are here in DFW. Cheers

[@austinbowman1433]

Would you be willing to provide feedback on the Dark Aero 1?

[@bartofilms]

I'd be interesred in this as well. That team really has their act together. It looks fast and compact even on stands.

[@ddegn]

I'd also like to see an outsider's look look at Dark Aero 1. I enjoy their videos. The main thing I've seen which I'm not a fan of is the way the control panel is part of the canopy. I'm concerned repeatedly flexing all those wires will eventually lead to one or more of the wires breaking. I personally think they should redesign the way the canopy opens so it doesn't cause repeated bending of the instrumentation wires.

[@billrb4855]

News flash for all the diehard fans of the never ending Raptor story starring Peter Muller…on Aug 6 2021, as reported by KOLN News in Lincoln Nebraska, Peter crashed the Raptor in a cornfield near Fairmont NE. Peter walked away from the crash, reported he stated the plane lost power as he was trying to fly cross country. Hmm…2nd time for engine failure…Looks like all us “naysayers” were actually right…just a matter of time.

[@rickpellicciotti]

I stopped following this project when I found out the empty weight was the same as a Beech Baron 58. No way it could perform as forecasted.

[@creativityworld6781]

appreciate your analysis .. I have such doubts in its announced figures but I kept it to the actual test. who knows .. comparing to Velocity I expect that Raptor will acheive around 60% of its announced performance figures.

[@pdspartner1]

Appreciate your very detailed analysis. I started watching early in the project but stopped after seeing massive mistakes being undertaken and solid advice being ignored. I think Peter will eventually kill himself when a structure fails in flight. He certainly will never sell this to anyone with a lick of common sense. He refuses to even embark on stall tests!

[@bh3141]

Thanks for having the stones to call out this terrible project. Peter's way way way over his head and needs to know when to quit. I get the feeling that he's waiting for something to happen in the air so that he can pop his chute and then collect the insurance money. Wonder if the insurance company knows that this is a real possibility? And the FAA? And I wonder what all the investors are thinking by now? I would imagine a huge class action lawsuit since $2.7 million is a lot of money. Sad that this project has taken so many people and taken away aero investors from other projects that are based on solid engineering and project management. I feel for Peter but he needs to cut his losses and move on to something he's good at like tech.

[@BIGWIGGLE223]

I couldn't have said it better. His willingness to play chicken with future customers lives has really pissed off a lot of people. I wonder how much time he spends going through and deleting negative comments after every single time he posts a new video. That's gotta be exhausting.

[@buckmurdock2500]

I seriously doubt he has hull insurance and doubly doubt he has investment insurance. Miracle if he could find liability.

[@hechtspeed]

The cooling system makes me LOLLLLLLL

[@ParadigmUnkn0wn]

It's a poorly designed clone of a Velocity that has already exhibited oscillation tendencies in flight, is massively overweight, is running a brand new auto conversion engine, and the performance claims are ludicrous. Not to mention the obvious engineering mistakes already exhibited and catastrophic engine failure. I'm not an aerospace engineer, but based on the simple mechanical engineering mistakes I've already seen I can't help but wonder what other oversights have been made. I'm leaning towards DarkAero for my first kit plane, and I think that team is a perfect example of how to build a new airplane. All 3 of them are engineers (one mechanical, one electrical, and one aerospace), the whole thing has been meticulously designed and analyzed with the best tools available, and they're actually hitting goals like weight and the math checks out on the performance claims.

[@nathanchalecki4842]

The line "how is raptor shaping up" made me laugh after recent developments.

[@timmiddleton7493]

The old standard New Airfame - Proven Engine or New Engine - Proven Airfrrame is a good mantra for aircraft design

[@rickfeehery7722]

I remember talking to a retired dentist at the open house he had in Georgia a few years back. He had just plunked down $25,000 for a "share" of the company and a chance for an early kit. I asked him why in the world he was willing to part with his money so readily for an unproved product with so many glaring engineering issues--I told him at the time that the doors, cooling, and that stupid elevator hinged system was not going to work. He just shrugged his shoulders and said "Got to spend it on something..." It's liked he mesmerized a bunch of high net-worth individuals into believing that this is the plane of their dreams, but in the end it's all smoke and mirrors. Peter is trading honesty for rank incompetence, stringing folks along, thinking that it's going to get better with a tweak here and there. But we all know from experience that this is not going to end well, when finally the engine quits for good over some uninhabited part of the country while he flies the craft to Oshkosh or out to California.

[@bernieschiff5919]

I remember watching the open house video. It seemed the potential customer base he was attracting seemed they might have had a limited aviation background, as your dentist. The U Tube videos apparently were intended from the start, as a way to advertise and promote the idea without addressing the numerous difficult engineering questions. As you said, selling a dream.

[@yashmanwani6232]

No mesmerizing fraud tries to fly his own plane especially if he knows it was smoke and mirrors that he sold to the public. He has risked his own life for this project, which proves to me he is sincere and not what you are calling him.

[@bernieschiff5919]

@@yashmanwani6232 We don't know what PM really thinks of his project, the You Tube videos and commentary have presented a one sided positive viewpoint that he wants us to see, and glossed over many negative aspects of the design, which have now become apparent, summarized in RV6jguy"s video. These videos have become a successful promotional and marketing tool for him. PM may indeed be showing determination and risking his life in continuing in attempts to fly this plane, and it may be an effort on his part to prove something to himself or others, but in the end, may just reveal a series of diminishing returns.

[@yashmanwani6232]

Positives and negatives are all out in the open. Nothing is hidden. Nothing is mesmerizing smoke and mirrors. All is out in the open.

[@nb9361]

Harsh, .....but fair. Some comments give praise for this guy's 'tenacity'. I look upon it as complete stubbornness & disrespect for other people's opinions. People who have far greater knowledge & experience of aviation than himself. Is he really an IT bod who has secured $2.6m of crowdfunding?

[@john8451]

Harsh, but needed to be said.

[@silasmarner7586]

The message was harsh but the delivery was smoooooth.

[@N807DS]

While I share your views about the potential for success from day one, I do have 2 questions about this video: in the acceleration calculation did you account for the forces opposing the acceleration, namely wheel drag and aerodynamic drag? Skipping these obviously leads to underestimating the available thrust. And the second question has to do with the BSFC figure you estimated for this engine. It is very poor for a turbo diesel- where does it come from ? And as a side note, one thing I have learned from an experienced aircraft designer is to review comparable existing aircraft when diing a new design. If you expect to beat their numbers by anything more than a few percent, you’re implying that you are radically more competent than their designers...

[@rv6ejguy]

Tire rolling resistance falls off with velocity and air drag increases with velocity. Both of these forces at the average speed of 40 knots amounts to less than 60 pounds force I'd estimate, so around 10% of total average force required. Since my 60% prop efficiency estimate is probably on the low side, this favored higher than true hp being estimated. If we throw in 10% more for air and tire drag, we end up with 253hp which is still 100+ hp less than the designer was estimating. My goal was to show from 3 different angles why the designer's hp estimates (based on fuel flows) cannot be close to correct. My video #106 discussed the improper matching of the turbos on this engine with is likely the main cause of the very poor BSFC figures being achieved here. The turbines are extremely restrictive and the small 1st stage compressor results in high CDTs. The extreme EGTs are a consequence of this and indicative of low thermal efficiency. Contributing factor could also be sub-optimal mapping of the aftermarket fuel injection system.

[@georgeingram9157]

I did my own calculations of actual Raptor performance a year or two back. They were close to the numbers Ross has in this video, including the atrocious BSFC. Before Peter revealed the fuel flow rate... Others who can also do the maths have come up with similar numbers too. So, there are those of who can do the maths coming up with numbers close to Ross, and Peter and fans with their wildy different (and hopelessly optimistic) guesstimates... Peter lacks the maths and physics to estimate true performance. He chose to launch the project relying on internet apps and his own guesses rather than getting someone who could calculate run them for him. $3,000,000 of other peoples money blown on wishful thinking.

[@leoa4c]

I will not venture into the mechanics of it. That is not my field. Ok... Aerodynamics. The area rule is not exclusive for supersonic aircraft. From Mach .8 upwards it starts to be relevant, however irrelevant in this case, since the Raptor will not cruise nowhere near that Mach number. The position of the canards. That is one which I really do not understand. It showed massive instability in scale model tests, yet they proceeded with the design. The canard is in the worst possible position. It is not in line with the wing, it is not above it, it is not well, well bellow it either! So, as the craft pitches and/or rolls, the canards' downwash and tip vortices change the CoP on the main wing. The stagnation point of the main wing keeps fluctuating due to the position of the canards. The cooling! The cooling is a mess. No separate inlets, no separate outlets. The heat keeps bouncing around from surface to surface, thereby destroying the efficiency of the entire thing. I wish him well. I sincerely do. However, he needs to start to listen. Nobody knows everything (least of all, myself). That's why we depend on each other's expertize for projects of this scale. Putting people into the air is a hazardous business. It should never be taken lightly or moved by tunnel-vision.

[@gul7809]

@ 6:00 (drag and lift): seems like Mr. Muller calculated with const. drag and lift coefficients (Fd=cd*A*rho/2*v² - as you might do in the automotive industry), ignoring that in level flight he needs only as much lift as the airplane weights... and at higher speeds and lower angle of attack cd and cl changes...(also with the Reynolds-number, of course) anyways - really great video, Mr. rv6ejguy!! thumbs up!

[@rv6ejguy]

I agree. He just didn't understand how to use the CFD program or what approximate real-world numbers for his design might look like. He was off by a factor of around 5 for drag. The L/D ratio made no sense either (off by a factor of 3-4) and he didn't know enough about propeller thrust with hp and velocity to do a back check on if any of his CFD numbers made sense either. I am not a professional aircraft designer but I know enough about these subjects to know that all his assumptions and calculations for speed and drag were massively in error as I've demonstrated here. You couldn't have 2000 pounds of drag force when you only had around 330 pounds of thrust force at 210 knots. If you did have 2000 pounds of drag, you'd need about 1500hp to overcome that! CFD and FEA software are tools for experienced people with aero and mechanical engineering backgrounds primarily. These folks know from experience and training what is at least in the ball park when the program spits out results. I've seen an over reliance on FEA these days to design parts without actual static testing to validate the results. That's dangerous and have seen a number a parts quickly fail in service. Computer models need to be validated by actual testing- especially in aircraft and are only as good as the numbers entered in. Too many assumptions made, often yields erroneous results for the output data.

[@kyleschirrmacher2433]

Peter seems more interested in clapping back at KZbinrs than he is in building a plane

[@big5astra]

Ironic in this video, you highlighted in no uncertain terms, that the re-drive was a big problem. And later 2021, the aircraft crash-landed as a result of the re-drive playing up. Mmmm ... Problem is, will Peter take a step back and re-assess, where he should be going in the wake of Raptor 1?

[@kylegoldston]

Well, reading the comments here. I'm really glad Peter survived what myself and others saw coming. Also oddly happy that I got chased out of his comments before I added any material support other than dire warnings. For the record that engine could have put out the power he needed in my estimation but not the way he configured it. BTW a PSRU on a Diesel is stupid no matter who does it. Lots of diesel engines CAN run above 2800rpm but NONE of them should.

[@mafp22w]

Almost makes me wonder if it was dumped in a cornfield on purpose.

[@yukon4511]

Do you also wonder why there is oil all over the engine cowl?

[@BrendaEM]

I agree that it was a mistake to do both the airframe and drive system. Peter did have engineering an aerodynamic help, early on. I think that he needed it for the control system. I and others wanted a push-pull rod system. The drive system was somewhat a copy of another, if I recall. Yes a static G-test would have been a good idea, too. To his asset, he did appear to have good method/system for getting his designs from CAD to moulded parts quickly and effeciently. As someone who has both worked with composites--and has done design, that is one of the reasons I became interested in his project. I think that he and his team could have made an ironic living--producing other people's designs. As I look back on seeing his videos, Peter knew composites, metal not so much. I called him out, and was even mentioned in one of the videos, because I wanted him not to put screw/bolt holes close to edges of metal plate. As for the canopy and windows. Well, acrylic is horrible plastic to ever trust your life on. It cracks so easily. Screwholes are an issue because of expansion and contraction. Polycarbonate has its issues too: UV, and microfracturing from cleaners such as isopropanol. The front landing gear issues became a time/effort trap. I feel that the cabin could have been a bit narrower, but it would be interesting to take that airframe, pull the corn husks out of it, inspect and repair it, inspect it again, pull the engine and control system, and fit it with something conventional, put two radiator ducts, one on each side of the plane, in back.and test it. Oddly, in spite of everything, and while the Raptor did not fly well--it did fly.

[@rv6ejguy]

The plane was hugely overweight, so useless right there for its intended mission. The whole thing was a s**t show from start to finish.

[@richardk100]

Ouch, this must hurt. I agree Peter needs assistance in many areas. However, I suspect that he had budgetary constraints and had to make some hard choices. One thing that is certain though is that his loyal fans will support him through thick and thin.

[@rv6ejguy]

By accounts had over $2M to play with. It costs less to do it right the first time rather than doing multiple parts over multiple times because you don't know what you're doing. One good engineer on staff here (if Peter would have listened to him) could have guided this project to a much better conclusion years ago. I agree his fans will support him until the end of this project, mainly because many of them also don't know how things are designed, made and tested in the world of aviation.

[@richardk100]

@@rv6ejguy do you think that Peter can save the project and if so what would he need to do? I for one would love to see this thing fly and be a commercial success.

[@rv6ejguy]

@@richardk100 Yes, I do but it will take money, time and outside talent to do it. A structural engineer needs to go over the whole airframe and find at least 300 pounds in weight reduction there and ensure the structure is safe. The Audi engine and redrive need to be replaced with a Lycoming , Conti or Adept turbo engine. This will save at least 250-350 pounds. If the Adept is used, it needs a completely re-designed cooling system. All the systems need to be looked at by qualified people- pressurization and controls especially. Before all this, it needs a proper flight test program to learn what else has to be changed or modified before a 2nd prototype or pre-production example is built.

[@keithturner3859]

@@rv6ejguy Ross , thanks for the well presented video review of the Raptor program. I think you are being optimistic in believing this program can be salvaged. There are way too many fundamental design errors and poor compromises that are inconsistent with the goal of 5 seats, 25k flight, 300 knots, etc. etc. By any measure this is a start over if any progress is to be made. The first task would be to define the mission and look at the compromises that are needed. What are the characteristics of the target purchasers. Aiming a 300 kt , 25k altitude 5 passenger airplane at somebody that doesn’t even have a pilot license is the first clue that Raptor is just one big scam. What we are seeing is the logical outcome of a scam orchestrated by somebody with very little aeronautical knowledge, no regard for the safety of those that he is conning or surprisingly his own safety. I think there is every chance he will have a bad outcome to one of the soon to happen flights.

[@rv6ejguy]

@@keithturner3859 It will take a complete re-design by actual engineers to be useful but ill will never come close the the original numbers posted which are impossible.

[@lear60man]

Well.....it crashed today. Pilot walked away. Unscheduled stop in the middle of no where.

[@nicklockard]

It was a lesson in how over engineering can lead to more hidden dangers than under engineering does. When somethings under engineered, its usually pretty obvious and avoidable. When it appears that lots of stuff was done to "fix" problems, only the most knowledgeable engineers and experienced individuals may see the potential hidden dangers.

[@mrpurcountry]

I was watching the video of that plane flying it seemed to constantly porpoise up and down not stable at all, glad you pointed out its flaws hope nobody tries to build one of these and end up getting themselves killed.

[@charlesfaure1189]

Well, the designer has shown up on Kathryn's report. Engine failure, landed in a cornfield, walked away unhurt. He'll get it done eventually.

[@charlesfaure1189]

By "get it done" I mean his life.

[@erichnlorischumann6233]

Thanks for the time and effort to clearly and without bias explain your thoughts on this project! I’d be real interested in your perspective on the Dark Aero project as well. To the untrained eye it seems very exciting.

[@rv6ejguy]

I do like what the Dark Aero guys are doing and they are actually engineers but they are again projecting performance figures and putting out kit prices before it's even built or flying. Why do newby designers have to do that? Why not get the prototype built, flying, sorted and tested before saying anything? Then you don't need to make excuses for any shortfalls. I don't see it meeting the cruise speeds they are projecting and I think it will come in a bit heavier as well.

[@BIGWIGGLE223]

@@rv6ejguy it's all bc people are too lazy and impatient to do anything the right way; From the bottom up. Everyone wants to skip over the part where they put their own money where their mouth is and instead go for everyone else's purse strings. One thing I really can't stand is when people think they can cut corners. What they're doing is light years ahead of that disaster, Raptor, but they're still doing it all wrong. They want to get paid before they even know exactly what they're doing.

[@TheOwenMajor]

@@rv6ejguy Because getting it flying requires money. And you can't sell preorders with question marks. It's one thing if your an existing manufacturer with sales to float R&D, another story if you need to figure out how to keep the lights on with no actual product.

[@JH-tc3yu]

@@BIGWIGGLE223 darkaero is 100% self funded. Three people can make a lot of money in 10 years as professional engineers, especially in a low COL environment

[@BIGWIGGLE223]

@@JH-tc3yu I forgot about that comment. And these guys have most definitely proven me wrong. I am cheering for them all the way now. Oof... That comment didn't age well.. lol! Live and learn I guess. Happy to be proven wrong.

[@RasianAY]

All your points seemed solid until #7 at 4:29 "Diesel engines don't make more torque than gasoline engines." Now I'm going to have to look into all of these. Looks like you have a good following of people that wont question a word you say.

[@rv6ejguy]

If you can cite some examples of actual diesel engines producing more torque with the same boost pressure pressure and displacement, please do. You can watch my other video discussing this topic.

[@RasianAY]

@@rv6ejguy Continental CD-300. Don't let the 300 fool you into thinking its 300 cubic inches. Its actually a 3.0L 182.3 Cubic inch engine. 300hp and 677ft/lb. Only thing comparable is the TISO-550 and that's a 9.0L or 550 cubic inch engine. Looks like highest hp on that is 350. All TISO-550 are twin turbo charged. The CD-300 only has one turbo and has a service ceiling of 20,000 feet.

[@rv6ejguy]

@@RasianAY I covered that in a comparison video here: kzbin.info/www/bejne/fXvcamasp8eprZI

[@cluelessbeekeeping1322]

Dang...watching this was depressing, but I appreciate your work. I so hope Peter succeeds...but by this, it doesn't seem to look likely.

[@TeemarkConvair]

i would amend your comment to "i hope peter survives".

[@cluelessbeekeeping1322]

@@TeemarkConvair ...this is true... I hate that I agree with you...but, yup.

[@kentscherm2213]

Raptor: Revolutionary Failure. ... there, fixed it for ya

[@philipm7054]

Peter is going to be famous but not for a good reason and sadly he won't be around to see it. As a 30 year aircraft mechanic and a&p for a good number of years i shake my head at his videos.

[@stevegiboney4493]

It does harvest corn well though!

[@satguy]

Not really at all ended up on the ground.

[@gpaull2]

Don’t trust an airplane designed by someone who doesn’t even know how to properly cut a zip tie.

[@stevenhorne5089]

Who's going to tell Peter, he needs to pay Paul?

[@volksyes9477]

Looking at the raptor what I see when he tests the thing?... I see band aids after band aids... According to Burt Rutan- Simplicity is king when it comes to aircraft design. I know he did not say it like that, but something like that.

[@ginacalabrese3869]

He's probably already spent all the crowdfunded money AND people's deposit money and those people will likely never see their money again.

[@ronnl001]

Don’t forget the equity he sold to get another mil or so

[@ginacalabrese3869]

@@ryanthomas2472 My bad as to customer deposits. It's obvious he's hurting for cash as he's so unwilling to make some of the more proper changes that are expensive and will stop him from doing flights. He's putting bandaids on the cooling issue instead of doing the proper changes the forced induction and cooling systems so he doesn't have to cut into the airframe in anywhere structural. Also he needs to figure out the static port issue. Lancair managed to find literally the only spot on the airframe to put the static port because they did computer testing to find a spot that wasn't effected.

[@christopherleveck6835]

@@ginacalabrese3869 when he was having the side stick issue, I carefully reviewed all the videos and listened intently to what he was saying but I realized there was a type of bearing he hadn't tested that works linearly and rotationally and I happen to have about a thousand of them in stock... I first got a hold of him said I had a solution and offered to send him enough bearings to do 10 Raptors for free. I had been hoping I could make a meaningful contribution, this was my chance. He said he looked at those bearings I didnt understand the problem and proceeded to tell me the issue that these bearings didn't fix and asked me politely not to waste his time on this issue again. My words not his he was very polite. I tried to tell him I DID understand the problem and these bearings would solve that problem specifically. No reply. So I mocked up a stick with brackets that clearly would replace his as a very simple elegant solution which would be rigid and not stick. It used two of my ball bearing sleeved linear rod mounted on a chromed hardened steel hollow shaft normally used in CNC motion machinery. .... I posted it on youtube so he could see it in action. I told him the video was 13 seconds long and gave him the unpublished video link and said if he wanted it I would send him a finished plug in unit if he wanted to give me the bracket drawings or I could send him the materials and a dozen bearings for free. He never responded nor did he take the time to watch the 13 second video. If he were serious about exploring options I could not have made it easier for him. The fact that he wouldn't look at a 13 video made me wonder what other stuff he hasn't looked at? My feeling at the time was I had challenged him and he had dismissed me. He is too proud or ego too big to admit he has been bested by someone else's idea. I admit, I'm a little butthurt. I understand why he would be. And that's the point, if my idea had turned out to be bad, I would have dropped it and conceded if it meant the better solution had been implemented. I think he needs to be the one to come up with the ideas. Once he thought he knew what I was saying he implemented something similar. The solution ended up being something he told me he had already though while clearly not understanding what I was saying. I'm not explaining this very well in other words he ended up doing what he thought I was suggesting while telling me it wouldn't work and refusing my help because he didn't want to share the credit maybe I don't know. The point is he ended up putting something in that was cheesy in my opinion. What really irked me was how he talked about how smooth his new solution was. He used all the same words I used to describe my idea. All he had to to was bolt this flight control stick to the existing panel and rear bracket mount. It had two captured bearings that allowed for smooth as silk effortless sliding and rotating of the stick and added rigidity instead of binding the system. With no way of ever coming our flexing which might cause binding in the system. There, I've got it off my chest. I feel better already. Its not just money. There are I'm sure a lot of things that he hasn't done because he wanted to be the guy who did it all.

[@robertkramer621]

@@christopherleveck6835 is the video still available?

[@ulbuilder]

@@christopherleveck6835 my observation is that he does not know what he does not know. He cannot evaluate if your solution is better or not because he lacks the prerequisite subject knowledge to properly evaluate the idea. So he goes with what he does understand and overlooks outstanding ideas. Lately he has become fixated on flying off the first 40 hours, a requirement before he can go into airframe production. I can only guess but I suspect that is a financially driven decision because it's the only logical reason I can come up with.

[@johngardiner1630]

I've lost any interest I ever had in this pipe dream. The original aircraft is repairable.... BUT .....most aviators realise it would never meet it's design goals........ so a new pipe dream gets created. but no real learning is occurring from this experience, meanwhile a humble, innocent WASHER takes the responsibility.

[@MrMartinglob]

Can't wait on your video on the Celera 500 ;-)

[@RalphEllis]

Absolutely. Now that really is a boondoggle....! R

[@paulo7200]

@@RalphEllis Boondoggle is too kind, more like straight up fraud.

[@davem5333]

Pipedream Vaporware Phantasy flier

[@blackhd92]

Great video.Lot of good points made.Underpowered,overwieght and a "iffy" engine.Sounds like my first attempt at model aircraft design.I have watched alot of this project and i agree,mostly a pipe dream.This thing will never make production phase.Not enough chiefs in this tribe.

[@bartofilms]

Just found out today that N352TD had another engine failure and emergency landing. This time in a Nebraska corn field. No Injuries, but nose gear and prop damage are evident from the photos.

[@rv6ejguy]

Yes, sad to see it down in the corn but glad PM is ok.

[@bartofilms]

@@rv6ejguy Likewise. His new NG proposal... What do you think of the boxed wing / cannard version of Raptor with ducted E-fans?

[@rv6ejguy]

@@bartofilms Here was my post today on HBA about the new Raptor design: I see lots of issues with the Raptor NG, even if the empty weight is reduced 500 pounds. TO distance will be even longer. ROC will be lower Drag will be higher with the fan ducts there and second wing Range will be less Speed will be less The low aspect ratio wing is a big killer here. This must be for a different mission now. It will be struggling to do 200 knots and won't be going anywhere near 25,000 feet either. I predict another lame duck here based on what we've seen so far for concept. Other challenges will be developing a lightweight 300Kw class Genset, battery cooling, the ducted fans etc. The trouble with hybid aircraft is they need a large percentage of power to climb and cruise compared to cars. They are more dependent on the IC engine to supply that power most of the time. You have an efficiency hit with the Genset, battery and motors and then a further one with the ducted fans. Cool maybe but not very functional for transporting folks efficiently. Seems like another marketing concept with little basis in physics or reality. Will be an interesting journey to watch...

[@robertrade]

Please enable English subtitles/Closed Caption.

[@robertrade]

Thank you..for enabling CC

[@jeffsmith9305]

I contribute to this project, in 2015, that the pressurization, the whiz bangs, the redrive, and the automated "systems" would be profoundly too complex. I recommended taking the TP100 as the basic powerpoint, no pressurization, not integrated steps when doors open... and that the unpressurized cabin + "simple" powerplant could make a lighter, faster to build, less systems to fail. I received a "nice "thanks, build your own plane your own way, but this is mine and you have to buy everything" ...reply