Working on a Turbojet: 12 - Cartridge starter

We've never had a cartridge starter on an engine before, so lets take a look at one.
For a paper describing this actual starter, and others, check out the link supplied by RickAtlantaPilot ... just below.

[@Blakearmin]

I don't know how I found your channel, but by God am I glad I did! I have no life goal to work on jet engine, but this is fascinating stuff! I've been binge-watching your videos.

[@AgentJayZ]

Thanks! ... I think you might have spelled dog backwards for some reason.

[@Blakearmin]

AgentJayZ I didn't want to say HFS on your channel since you make the effort to not swear and you seem to have a wide range of audience members. BTW, I love how you won't help students with easy answers. You make them work; that's great! You're cool af, man.

[@lmelin1959]

lol, at 14:55 "one beer bottle full of oil",.. Enjoying all your videos Jay, good stuff.

[@MrLohatoolvebyte]

Those engines consume so much fuel when they operate that it amazes me how the designers can find enough room in the aircraft to keep it aloft for a practical period of time. The first design priority has to be; make it a flying gas tank and only after that you can add the useful bits. The thought really makes you scratch your head. WOW! Thanks for all you do Jay.

[@AgentJayZ]

For the Phantom II, with two of these engines, that practical period of time was less than half an hour. I've read many books written by pilots who flew the Phantom in combat. They all mention that they kept one eye on the fuel gauge at all times, and the location of the nearest aerial refueling tanker was always on their mind.

[@MrLohatoolvebyte]

WOOOOOOOOOOOOOOOOOOOW!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Thanks for the info. Sounds like I need to do some more reading too. ; )

[@nastynorth852]

Stumbled on this page. I love it, thank you

[@unclemonster48]

Jay I’m a industrial air conditioning centrifugal mechanic and I have always been interested in jet turbines. You have been a book of knowledge over the years and I’ve learned and laughed a lot watching you. When you described compressor stall it matches what happens in a centrifugal chiller when it loses its lift capability. In my world stall follows surge, which is the reverse flow of refrigerant back through the impeller going the wrong direction. You are a master of the craft! Please keep doing what you do!

[@xiaxia686]

Even the vin plate is wire locked. I am impressed.

[@cliffcampbell8827]

When you are flying around up there, you don't want anything (and I do mean ANYTHING) falling off of your plane but especially the engine. The FAA would require your chewing gum to be safety wired, as you're chewing it, if they could.

[@anubisokc8718]

Thank you for this video! I was in CAP back in the 80's and a friend of mine and I hung out at 465th TFG which at that time was all F-4's. The crew chief we hung out with told us that there was another way to start the engines other than the start car. The furthest he went was basically there is a "can of gunpowder" attached to the engine and in "emergency" situations you could start the engine by setting it off. He told us that it is really hard on the engines and makes a whole lot of smoke. I have always really wondered how that really worked and just finished your video on "how to start a jet" and it got me thinking about that very thing and **WHAMMO** the next recommended video way this one! It was like KZbin read my mind. Scary.... Anyway thank you for explaining specificlly how this worked, I feel like you have answered a question I have thought about since I was 16!

[@AgentJayZ]

Thanks! It's comments from people like you that are mostly the reason I make these videos.

[@hugooooo2011]

Anubis OKC i

[@Raulcb400f]

Hi AgentJayZ, I have been a big fan of your work for a long time and I have noticed that in your latest videos you are more relaxed and good humored which makes your content very pleasant to watch. Thank you very much and please continue educating us. Greetings from Argentina.

[@Mishn0]

Back a million years ago I saw a magazine article where they made a dual engine Honda Civic. They took a second engin/transaxle assembly and put it in the back of the car.

[@sweepleader]

Jay, your stuff just get better and better, thanks!

[@krugtech]

I think that blower also helps keep rpm under control. The cartridge gas generator doesn't shut off when the rpm gets too high. I have one I'm going to try running on steam. Keep up the good work old friend!

[@toadman506]

GREAT Video Jay, this is one of the things that you just never get to see up close if you're not actively working with them, even in the FM's it;'s a line drawing of the Cart Starter and Breech. I think 've seen exactly ONE maybe 5 second clip of a Crew Chief installing a Cart into an F-105, from a distance with no details of how it sits in the aircraft, or even what the breech end really looks like

[@arthurmario5996]

these engines are like cathedrals (or holy icons) to tech. probably millions of man-hours over the years to develop. went from amazingly simple to amazingly complex. (while retaining amazing reliability!!!). So much for the idea that very complex things can't be reliable.

[@dalebraun5497]

450 ft lbs of torque in a second or two....amazing considering the gearing and weight needed to get rotating. Thanks for sharing.

[@scarecrow1323]

Hi Jay, it's Ben from London, Ontario again.... dude you are the best. Your dialogue while you work is comical and informative at the same time. Bravo kind Sir. I am a 310T Diesel Technician and I am at the top of my field. I enjoy sharing my knowledge and experience with the younger generation (even though sometimes they don't want to hear it).... and I would like to offer the same to you. If you have any interests or technical questions, please let me know and I would love to answer them for you. I have decided that when I turn 50, that I am going to start an apprenticeship for Gas Turbine Jet Engine Overhaul Technician and set myself up to tinker with jet engine while "in retirement". I have always been fascinated by military aircraft and would have loved to have been a helicopter mechanic. Anyway.... thats my piece for today. Keep up the excellent work. 👍

[@edwardarruda7215]

Worked on KC-135A had 4 cart starters

[@Digit654]

All USAF aircraft that stood nuclear alert used cartridge starters. B-52s used them on the #4 and 5 engines using the bleed air from the two running engines to start the other 6. The F4D used cartridge starters on both J-79-15 engines. Usually they would use Ground support to start the aircraft during regular training missions. May I point out something I noticed. Installation of the starter band clamp, you could have placed the band clamp after dropping the starter in place then bring the clamp in from one side of the flange and worked around the mating flange. I’m not trying to tell you your business, just trying to simplify a job I did many times on the J-79/F-4.

[@davidwalle5025]

Digit654 the 52 had the capability for all 8 engines to have cartridges for a quick start the cartidges were made by olin in east alton il

[@Digit654]

David Walle Yes, David you are quite correct. However, in practice, rarely were all 8 used in cartridge mode. KC-135s on the other hand used cartridges in all 4 engines. The BUFFs just started faster using the 2/6 method. In my time in SAC, I never saw all 8 engines use cartridges.

[@killman369547]

@@Digit654 Yea, using all 8 cartridges would mean they need that bomber moving ASAP because missiles are incoming.

[@jimporter7602]

Lucky to see 3 cartredge startson F-4D at Udorn RTAFB in 70-71 and was ground man for a cartredge start for maintance on J -57 KC-135A. RPMs came up really fast, almost lnstantly RRM were 30% at Kadena AFB in 72

[@RickAtlantaPilot]

Jim Porter - were the cartridges used in those starts because of a lack of start carts available or another reason? Thanks for your service!

[@jimporter7602]

No they were the alert aircraft, parked near the end of the end of the runway, were armed and ready to go if any migs got to close. We were about 200 miles west of North Viet nam

[@HerkCC]

F111 would fly with several for cross country trips incase there was no -60 available. I hated cleaning the breech cap after they were fired on the #1 engine.

[@CAPFlyer]

On the "exhaust turbine" device - I wonder if it was installed not just to cool the heated exhaust, but also to make sure the starter is properly evacuated as the cartridge "burns out" and pull out any particulate and gasses that if allowed to build up could cause damage to the turbine wheel. Even at that, I have to wonder how much velocity is lost from the cartridge stream once through the turbine so it may also be to simply energize the exhaust stream sufficiently to evacuate the turbine volume since the exhaust stream itself wouldn't be sufficient after expending all its energy on the turbine.

[@AgentJayZ]

A couple of good points there.

[@RickAtlantaPilot]

This video shows a German F-4 doing a cartridge start. I think what you say @Chris Trott is likely why there is the ventilation impeller as this thing makes a lot of smoke. If watching on a PC, you can press the "Shift-Left Arrow" key a few times to slow down the playback - and really see how much comes out: kzbin.info/www/bejne/qKDHgYOopaakjLM

[@SquillyMon]

Those GM models used longitudinally mounted V8's coupled to FWD transmissions. No Transverse mounting. Just a little factoid in case you were interested, not super important...but there you have it.

[@shishetube]

Thanks JayZ for another great video, today Saturday I spent most of the day at Palm Springs Air Museum were I found a J79 engine with afterburner, it was so nice to put my hands on it and identify most of the components even the “Oh crap ring” one of the volunteers come to me and ask me if I was ok when she saw me on the floor taking pictures at the gear boxes and pumps. This engine has only 2 fuel lines to each afterburner spray bar so I am assuming it’s an older model.

[@AgentJayZ]

I've been there and seen that engine. I think I checked the data plate, but I've forgotten what model (dash number) it is. Dude, please use my full username. I don't want to attract the ire of that famous guy who may or may not have objections...

[@bobparker9511]

Nice work! Thanks for sharing.

[@SOU6900]

Not sure if you've seen it but there's a video on KZbin of an F4F Wildcat being started with something like this.

[@carabela125]

I saw the starter for the engine of an ME-262. It's a 1 cylinder internal combustion engine with a pull rope to start it.

[@josephspratt2055]

They used to have them on bulldozers and other large excavation equipment, they were called Pony Motors (they weren't really motors, they were engines).

[@Subgunman]

Cartridge start combustion gas cooling compressor. One could possibly machine a plate to block the impeller opening. If it is not sucking air in, which would add an additional load to the air starter, that means less of a load imposed on the air starter section. Kinda think of it as an impeller rotating in a vacume.

[@danielthechskid]

My thinking exactly, though this appears to be a mixed flow impeller, partly axial partly centrifugal, I wonder if blocking it would reduce or increase the load. It's worth a try.

[@hommie789]

Holy crap, 90 gallons of fuel a minute per engine times two engines is 180 gallons. That's 1206 LBS a minute, hard to believe they can carry that much fuel. BTW I know it's splitting hairs but GM didn't put a 454 engine in a Corvette in 1978, last year they put it in the Corvette was 1974. Have a great weekend Jay awesome video as always.

[@AgentJayZ]

I actually know almost nothing about cars.

[@BillyNoMates1974]

would love to see how much snow there is there and the white out conditions

[@hehawification]

Tonnes of it (snow) It would shock you to see

[@alexcorado6732]

It seem to be great stuff and all, but how did I got this on my recommendations?? Even though I couldn't make heads or tails of it I watch till the end lol

[@shafiullah5348]

Very nice I like your work

[@listerdave1240]

@12:49 That housing looks like something I might make. Does it come out of the factory like that or has it been poorly repaired/modified in someone's garage? Or is it just me thinking it looks awful but it is actually OK?

[@AgentJayZ]

It's all as made, unmodified.

[@matthewkendall7791]

Definitely not the prettiest welds in the world, but I guess as long as they hold it doesn't have to be perfect. Let's call it "rustic" welding.

[@EricTViking]

I hear your workshop music, I see you are also a man of culture! 😁👍 Really enjoying the videos m8 - keep up the good work!

[@AgentJayZ]

Thanks 👍

[@MemorialRifleRange]

I have a fascination with Cartridge starts. I have a brass base of one cartridge that was used on a Radial engine in the US, I always wondered if they were reloaded and what was used to load them with in the 1st place.

[@kevyelyod1211]

Safe drive home !⛄️☃️

[@vector6977]

Would be awesome to see a cartridge start on one of these.

[@toadman506]

kzbin.info/www/bejne/hXineGafib6Ahrs

[@RallyRat]

That impeller probably can't absorb much power at only 3400 rpm. My guess is that it is there to pull fumes out of the engine compartment during starting, and maybe evacuate some of the nasty chemicals and heat from a cartridge start as the starter is spinning down.

[@AgentJayZ]

+rallyrat The torque spec is at the output shaft of the starter... which is powered by the actual air turbine through 2 stages of reduction gearing. The turbine itself probably spins about 35 thousand or more rpm at full speed.

[@dalesmth1]

Like the old Turbonique engines if the early 60's. That thing was a death trap.

[@tomuchfunwithgas846]

Two many !'s. I worked on a few f4c's.

[@perrydiddle3698]

So, the cartridge starter only fires for a few seconds? How much time does that give you to start the main engine(s)?

[@TheProfessor936]

A few seconds?

[@BeechSportBill]

Looks like a GE supercharger from a P-38

[@AgentJayZ]

I think all jet engines are related to that turbocharger, aren't they?

[@randymagnum143]

Allis-Chalmers built a lot of them.

[@drewthompson7457]

Hi Jay. Thank you for all the info you post. In the first couple of minutes you talk about hp conversions. At work, a professor, (ex- Orenda), told me that at a certain height, 1 lb of thrust is equal to 1 hp. (I forget what altitude). Is this accurate enough for non-trade people? About your "Micro adjuster". I used to install video heads to about 1 thousandth of a mm. I Always thought it funny that I tapped them into that accuracy with the handle of a screwdriver.

[@RehanRehan-ym5pj]

How start the engine selfe do thae .kick how

[@allensanders5535]

I agree with not agreeing with the second method of calculating HP using speed because as in the F-4s case a lot of planes are structurally limited in its speed and not in engine thrust. the F-4 can and has been flown well above its structurally listed speed limit, plus no 2 planes will fly at the same max speed do to deference in aero drag. (just my opinion)

[@grandpacocky7618]

Some of those welds look pretty...ordinary.

[@ToshRoberts]

Oh cool I have one of these complete.

[@nicholascaro1364]

Cap or remove fresh air intake wheel and you will have a more efficient starter

[@jordanbrown7786]

Hey Agent Jay Z.; any chance that your company has a branch located in Southeast Washington? Only two weeks into my second job and finding that half the time my sanitation supervisor is having us do the work ass-backwards. Would honestly rather be working as a part of the sanitation crews at the Tyson Foods slaughter and processing plant.... Any words of advice though if there is no branch of your company in Southeast Washington?

[@AIM54A]

The screw in part by the inlet for the combustion air that's lockwired down, Is that a relief valve or a mesh screen inlet filter? Its the item in the lower left of the frame when looking at the data plate. 13:27

[@AgentJayZ]

I think it's a relief valve for the combustion gas inlet.

[@sw5334]

Near the end of the video you talk about the impeller cooling the exhaust, would it also be possible that the impeller draws air in/around the canister to also cool the canister after the charge is set off? Maybe on the original there was a shroud around it. Maybe this has been answered in the last couple years. Thanks. And cause I'm also Canadian....Sorry

[@grahamj9101]

Hi AgentJayZ! Perhaps you should have explained for those in North America who are less knowledgeable about foreign customs that the gesture showing two fingers extended with the palm towards the the body, which is used in the UK, Ireland, Australia and New Zealand, means exactly the same as showing the middle finger over there. However, with American culture becoming more widespread, this ancient practice, which is hundreds of years old, is being usurped over here by the single finger gesture.

[@AgentJayZ]

I guess I expected a lot more folks to know that. I t was all in fun, of course. The last time I saw that gesture was on an episode of Benny Hill.

[@grahamj9101]

My comment was also made with my tongue firmly planted in my cheek. So you used to get Benny Hill's shows aired in Canada? Sid (correction: Fred) Scuttle rules OK! Or should that be UK? We still get some of the old Brit sitcom series, such as 'Dad's Army' (one of the best ever made) endlessly repeated. I have a vague memory that the platoon all gave the V-sign (and not Churchill's) to a portrait of Hitler in one episode.

[@RDC_Autosports]

are those adjustable veins i see at the bottom of the engine?

[@coalsmokegood]

I use to make the cartridge that goes on that starting unit. I have a bad one a the house that I tell people about.

[@AgentJayZ]

I know a guy who serviced that system on Phantoms in VietNam. He hated those things. If it didn't go off, you were supposed to quickly remove the cartridge and replace it. Sure... holding a rocket motor in your hands that has been "lit", and hoping it doesn't burn your arms and face off.

[@kevyelyod1211]

@10:38 AgentJayZ picking up helpful pointers from his comments crew😉👍

[@zuestoots5176]

lb/hr means a hell of lot more than Gallons per mile. at 65mph, i get around 30mpg, that means lb/hr of about 8 pounds..but it only makes 210hp

[@drubradley8821]

At about 12 minutes 45 seconds, when talking about machining a "coin" cover block off plate on the starter... There is a (?) hose barb approx 1" to 1.500" diameter that is wire tied. Assuming that the hose barb has a threaded end that screws/plumbs into the casting aluminum body.... My questions is, do these engines use a thread sealant or teflon tape of sorts, or is the mechanical factor of the A/N or B&N or what ever type of thread they may be, good enough, as per the convex to concave mating surfaces good enough... I realize that the simple NPTF or NPTC would not be found on aviation due to the funny nature of NPT theory. I would like to guess, that if "NO" teflon tape or other type of sealants are used, would be due to the possibility of foreign contamination being entered into the system ,and likely most of all, the mechanical nature of the A/N type fitting seal just fine with out anything on the threads, right? feel free anybody to correct me if I am wrong or missed something. I have not come across any reference for or against this in my book, I suppose, as detailed as the book is, if it is not there in the book, that would mean that i better not be there on the real thing? LOL

[@AgentJayZ]

It's not a hose barb. It's the body of a relief valve. Pipe fittings are an abomination to all things technological, and are not found anywhere on any aircraft turbine engine anywhere, as far as I know. Pipe wrenches are implements of bludgeoned hackery; there are exactly none in the tool inventory at Jet City. All of the tubing fittings used on all of the engines I've ever worked on are quite capable of meeting their performance specifications without being smeared or otherwise contaminated with any sticky or slimy products that are often referred to as "sealants". NPT roughly translates into "If I have to touch that, I might be sick, so have a bucket ready".

[@5695q]

Jay, have you have worked on any JT8D engines from B727's, pod engines for #1 & #3 have the cross shaft with a crank arm attached to the other end on one of the engines so the cable coming through the pylon can connect to the fuel control. I don't think the throttles are interconnected at the engine but may be at the quadrant. My AFM for the F4N is in storage so can't reference it right now.

[@AgentJayZ]

Have not worked on a JT8D before. I would like to, though.

[@arthurmario5996]

Black Sabbath at 22:00!

[@scotty8630]

Is there a bendix on this starter?

[@AgentJayZ]

These starters are made by Bendix, if that's what you mean.

[@scotty8630]

@@AgentJayZ I was thinking about the mechanism in a car starter that throws the armature into the flywheel and then retracts when the car starts. Is the jet engine starter retracted in the same way?

[@AgentJayZ]

I've got videos on jet engine starters.

[@scotty8630]

@@AgentJayZ Thanks. I will look for them.

[@scotty8630]

@@AgentJayZ I just found out about one way bearings in starter clutches. Now I know how it works. Really innovative. I wonder why they don't use them in cars.

[@Pro5.0]

Hi @AgentJayZ, I was wondering what would say an LM1500 setup for a Power generating style turbine cost brand new vs used but refurbished to near perfect condition by you guys there in Canada? Just something that popped into my head and was wondering...

[@AgentJayZ]

Not available new. But a general rule for industrial gas turbines is one million per megawatt. Overhauled serviceable units can be about 90% cheaper.

[@mikezaq1]

Are there any ground-based turbines that do use a cartridge starter?

[@TheDisabledGamersChannel]

Question, what makes Turbine engines whine real loud and make that incredible noise upon startup ?

[@AgentJayZ]

Two separate questions. 1) The interaction as the blades pass the stators. It happens many times per second. 2) Incredible noise is too vague. Could mean a lot of things. Have a look at my vid called Rolls Royce Olympus... You'll like it.

[@TheDisabledGamersChannel]

Thank you so much for the reply, much appreciated, it's great to see a content creator interact with subscribers, kudos to you sir.

[@grahamj9101]

The "incredible noise" on start up is frequently a phenomenon known as 'combustion rumble'. It's a form of acoustic resonance in the combustion chamber, resulting from a transient combustion instability. I fly on B.777s quite frequently, and when GE90s start up, the whole airframe is subjected to a brief, but quite noticeable level of noise and vibration, which can only be caused by this phenomenon. In contrast, the start up on Trent 800s is relatively more benign. PS The 'howl' produced by the Olympus is music to my ears.

[@TheDisabledGamersChannel]

The howl is music to my ears as well, thanks for the info, much appreciated.

[@grahamj9101]

And I happened to work on the machine that makes that howl.

[@seannot-telling9806]

No reverse threat threading? Well I guess we live with it. We are all captive anyway.

[@AgentJayZ]

What's a reverse threat? A bonus?

[@seannot-telling9806]

Yes I think that would work and you did give us a good showing.

[@Dr.Guryay]

Hello Jay! Was there a seal before the adaptor? During operation does the adaptor get filled with oil? Is there a drain for the adaptor flange which opens to the EMAD? Thanks...

[@denniswagner3962]

That 4 inch hose looks more like 4 cm to me. What am I missing?

[@AgentJayZ]

It's a 2" hose with a 4" adapter on the end... as described in the video.

[@denniswagner3962]

AgentJayZ in the video you reference a 4” hose.

[@scottbatchley6923]

Is that like the kaughman starter they had a long time ago?

[@scottbatchley6923]

I am aware it just reminded me of the old starter Thanks

[@fps079]

When you run these engines you never mention or show a de-preservation run. I assume none of them are in a preserved state when you get them. Is that because you are getting the engines directly after a rebuild or recent use? Just curious. Great videos. I watched the whole J65 run and was curious about the oil smoke too. I thought you had a leak. Thanks for explaining.

[@AgentJayZ]

We test engines after building them. Sometimes we preserve them after testing.

[@SheepInACart]

To bring the temperature down, or to provide extra oxygen to help burn off combustion products? Stable solid oxidizers are very weight inefficient, turbines can be oxidized but not reduced and burning near a stoichiometric ratio would generate the hottest possible exhaust (which since its not heating a ton of nitrogen like a jet does, could be ridiculously high). Thus I think its highly likely the cartridge would burn very rich so as to not damage the turbine (as would be supported by the turbine being covered in oil\carbon based nastiness), and thus the extra air would actually be for completing combustion afterwards.. although I can't think exactly why they wouldn't just let it do so externally. Maybe the unburnt products are too toxic, or the huge plume of smoke\flame unsuitable? Maybe the back pressure is actually desirable, as it self limits the starters working pressure, allowing more variation in cartridges or engines? Maybe its actually the vacuum off the little turbine thats used for something during the start, and they don't care what happens to the air at all? All guesses, so probably something else entirely. Either way it'd be very interesting to find somebody who knows, because my quick google found very little mention of this little air turbines role in the cartridge start. The linked pdf by RickAtlantaPilot call it a "turbine braking fan", so perhaps it prevents overspeed?

[@AgentJayZ]

It would not bring the temp down. Combustion takes place in an environment of excess oxygen. So... unnecessary at best. Destroy engine at worst.

[@lloydevans2900]

Strange as it may seem, pyrotechnic mixtures for gas generators do actually produce a fair bit of nitrogen. What you want most from one of these cartridges is lots of gas very quickly to generate pressure, rather than excessive heat which would just munch the turbine. The pyrotechnic charge is probably cordite or some similar variation of smokeless powder. These have the oxygen for oxidation tied up in nitro groups attached to organic molecules, like nitroglycerine, nitrocellulose (aka guncotton) or nitroguanidine. The oxygen from the nitro groups burns some of the carbon in the molecule (or all the carbon and hydrogen too if the oxygen balance is positive), which is the source of heat energy. The leftover nitrogen from all those nitro groups becomes nitrogen gas, which doesn't contribute much extra heat but does add a lot of gas volume. For example, nitroguanidine has the formula CH4N4O2, which burns to produce CO + H2O + H2 + 2 N2. All gases, 40% of which is nitrogen.

[@thomasburke7995]

A micro adjusting tool... I would cringe to see what a BIG F@+£//=£:!NG hammer looks like ... Keep up the excellent work man...

[@killman369547]

you won't see a big hammer anywhere near a jet engine, a rubber mallet is about as close as you'll find.

[@MrGoldman9]

ohhhh boy I love the way how you fuking take men I love your video and honda car imagination that's mean a lot of experience and funky comedian personalty .........beg fans to you ...man I love your video and your education way .....from an overseas pilot

[@snowballs442]

It was two Toronados......

[@kevyelyod1211]

Manufacturing Question! Why does the GE J79 have parts on it with branding from companies that are not GE? Is GE similar to Dell computers in that they don’t make parts they just assemble parts from hundreds of suppliers and then call it their own?

[@AgentJayZ]

+Kevy Elyod The engine was so good, over 17,000 were made. Many countries produced it under license, I guess to create jobs for their own people.

[@skrame01]

I'm interested to know where the actual thrust force is developed inside the engine. I know thrust is developed as a reaction to ejecting the exhaust at high speed; this means there are pressures inside the engine acting on the casings to develop the engine thrust force. You said the rotor has no thrust load that contributes to thrust, so I imagine it is the stator blades that have presure differences on them that actually force the case forward, is this true? When I sketch what I think these forces are it doesnt seem to add up. Thanks.

[@AgentJayZ]

If you google turbojet thrust distribution the first hit is a diagram I like, and it will point the way...

[@skrame01]

AgentJayZ Thanks, very interesting, however I noticed the illustrations seem to contradict each other. The F graph shows the burner section does not contribute much thrust, but the diagram below it shows the combustor section contributes more thrust than the compressor section. Interesting. I will search more. Thanks.

[@grahamj9101]

You will, most probably, have found a diagram based on the dear old R-R Avon, lifted from the pages of an early edition of 'The Jet Engine' by Rolls-Royce. We've been through this issue before on this channel and the basic answer is that the net thrust of an engine is the summation of all the forward loads on the engine internal components, minus the summation of all the rearward loads on all the engine internal components. But what happens when the vectoring nozzles of the Pegasus engine in the Harrier move to point vertically downwards and the aircraft is in the hover? The thrust is exactly the same, so what's happened?

[@skrame01]

grahamj9101 I'm just learning about jet engines. The loads on the components are of interest given the large amount of power the machine generates. A device that produces high speed flow accelerates the flow, and thus there must be a net reaction force, physically caused by static pressure acting on internal surfaces in the machine. The harrier nozzle is open to atmosphere, the unbalanced internal pressure in the gas delivery tube opposite the nozzle area lifts the plane.

[@grahamj9101]

If you've been following my regular contributions to this channel you will know that I had a career of over 40 years with R-R, designing gas turbine engines - and, if you didn't, you do now. This was my exam question for you. You have passed! Equally, you could do a similar calculation for a 'conventional' engine, without summating the internal loads, but an engine design team needs to know what those internal pressures and loads are.

[@Subgunman]

Someone enjoying a little Ozzie Osborn in the background arround the 22 min mark. Paranoid.

[@paulmoir4452]

I believe these were previously revealed to be secret and mysterious messages being received. They are in no way related to commercial copyrighted material.

[@grahamj9101]

No, that's just a malign satanic influence, which sounds like Black Sabbath, being picked up as interference. Any acoustic resemblance to the band from Aston, Birmingham, UK, is a total coincidence. PS His name is Ozzy Osbourne.

[@paulmoir4452]

I stand corrected!

[@grahamj9101]

And I wasn't able to get to a farewell tour gig.

[@todddembsky8321]

Drive Safe, in Minnesota, when we know we are going to miss the road, the driver hands his beer to his mate and says "Watch This". Fun video, I love Jet porn. It is a beautiful thing.

[@RickAtlantaPilot]

Awesome video as always! 2 quick questions: 1. When you installed the improvised medallion to cover the opening for cartridge start gases, did you have to use a sealing compound (like an RTV gasket compound that can handle high pressure) or are the flat mating surfaces and clamping force enough to make any leakage negligible? 2. Do you know and, if so, can you share if the power facilities operating the gas generators have a "shop air" type of system for starting them or do they have/use start carts pulled in as needed? Thanks as always!

[@AgentJayZ]

There was no sealant used on the original connection, so I didn't either. We will also not be sealing against hot gases, just start cart air, which is about 30 psi. Some facilities use compressed air from a reservoir, or natural gas regulated down from pipeline pressure. Some places use unregulated natural gas, which is very hard on the starter.

[@YCbCr]

Now this makes me think about a turboexpander used to regulate (natural) gas pressure and in the meantime extract energy from it. It looks quite interesting even just as a museum set. 40/6 bar, 86500 m3/h, 2850 kW. :o

[@skrame01]

When rebuilding an engine is it a thing to test any parts for cracks?

[@AgentJayZ]

There are many things used for testing parts for cracks. The most popular by far is a thing called the MK.1 Eyeball, accompanied by a strong light source and often a magnifying glass.

[@skrame01]

So no dye penetrant or xray?

[@AgentJayZ]

+Stephen Kramer ...you asked if there were any. I described one. The most common one. Then you assumed there were no others.

[@skrame01]

AgentJayZ ok, maybe my question should have been more general such as do you have to inspect for cracks in parts when rebuilding an engine, and if so how do you do it, or is it unesessary, say, because if a crack is too small to be seen visually it's not a problem. I assume you don't have to inspect every surface of all parts with the magnifying glass?

[@williegillie5712]

JayZ was a picking and a grinning

[@greg0063]

If this is a J79 going back in a plane is it legal to modify the starter?

[@anthonysibley1021]

He states its going into a ground based application

[@greg0063]

Thanks I missed that

[@arthurmario5996]

Who are your main customers!

[@AgentJayZ]

It's confusing that your words are arranged into what might seem like a question, but are punctuated with a character that is used to indicate a forceful command or a shouted warning. If this were a subassembly, it would be rejected, and possibly sent for disassembly/inspection/ testing. I'm just going to reject it.

[@arthurmario5996]

+AgentJayZ sorry, fat fingers. meant "?". I'm sure you get a lot of jerks, sad to say.

[@heedfulnewt6625]

toyota prius needs one

[@jasonlabby172]

Hello AgentJayZ, would like to thank you for all the cool videos you make. Not sure if you've mentioned it already, but I would like to know how your working for. There's S&S, Madex, and Jetcity, seems like you are part of them all. Please explain the status of these companies and how they relate to you. I tried send private message but can't find a way to do so.

[@AgentJayZ]

I've worked for all of them in the past, two of them now, and I also own one. Easy!

[@tomuchfunwithgas846]

F14 a thirsty bird.

[@raygun23]

The Commies and the Cholesterolites, come together as one.

[@jdesmo1]

Hi. This is not a air/cartridge starter. Its a combination air and combustion starter. A turbine cartridge starter uses large shotgun looking shells, and so the cartrige housing is much smaller than this combustor can housing. An example of triple-cartridge starter (gives 3 start attempts) can be seen here in action: kzbin.info/www/bejne/bXymlH2cpa6qd6s Cartridge starters have typically 1, 2, or 3 cartridge configurations. A combustion starter is basically a gas-turbine starter minus the compressor. I uses compressed air piped in from a remote bottle combined with introducing fuel and ignition (via plug) into the combustor

[@AgentJayZ]

+jdesmo1 Interesting that, as shown in the video, the manufacturer has labelled this item Starter, Engine: Cartridge/Pneumatic. I was going on that... and the fact that this is not a combustion starter. Also that it uses cartridges of fuel/oxidizer mixture (combusting) to generate the gas that runs the turbine...

[@HuntersMoon78]

2 Thumbs down, those plebs probably think they're better than you AgentJayZ

[@pythongunner]

Must be getting close to beer:30

[@zyzo99]

Know why russian fits perfectly? Two, strategic reasons, 1st. It was based on western technology/i.e. stolen/. 2nd Easy to replace-in case of a conflict. Yes, its a state of state and state of mind.

[@kevyelyod1211]

J79 afterburner nozzles are angled slightly down in cross section diagrams of the F4 phantom, why is this ? Or are my observations incorrect? Example-> goo.gl/images/Vk3b24

[@AgentJayZ]

I've noticed that too. Even looking at the actual aircraft... I have no idea what's going on... but the engines must be angled inside the fuselage.

[@jimporter7602]

I believe that is the way the engine is installed in the aircraft, at has been 48 yrs. Since i worked on a USAF F-4 J-79-15and-17. We had special tools to keep the nozzle aligned with the engine

[@ASJC27]

In many cases of longitudinally stable aircraft rear mounted engines are installed at a slight angle to produce a specified pitch-up moment. This means that at cruise the required pitch up moment for trim can be partly or fully provided by that thrust vectoring and so little or no elevator input is needed. That results in reduced trim drag (at the cost of a slightly higher thrust requirement).

[@kevyelyod1211]

ASJC27 wow that’s some detail there, would you be able to refer me to some books you may know about that deal with that kind of design knowledge?

[@ASJC27]

You could look at Raymer "Aircraft design: a conceptual approach" (a book that probably any aerospace engineer is familiar with). I'm not sure if that specific issue is discussed, as it is a very basic consideration but that book covers nearly everything to do with conceptual design. It is an engineering book though so depending on your background you may find it too technical.

[@makecba]

Jay, I'm suprised by the lack of swearing in your assembly videos. Are you deliberately keeping things PG-rated or you just don't like to swear?

[@AgentJayZ]

Oh, the live show is a bit saltier than the televised episodes...

[@gbowne1]

put that on your V8! :)

[@billyost1479]

You forgot to mention why the gloves. No doubt it's obvious... but still. Lol

[@krugtech]

Hey buddy I have one of those. I'm going to try to power a drag bike with superheated water, like a steam rocket free turbine. I think you're right, the compressor wheel provides some cooling but I think it also provides some overspeed protection too. BTW I'm selling the van if you know anyone who is interested.

[@arthurmario5996]

are most Canadians cool like you?

[@kubeek]

A bottle of actual beer is 500ml.

[@hommie789]

In Canada, where Jay is, most beers in bottles are packed in 12 OZ bottles which is 355mL.

[@donaldstanfield8862]

2nd - WHEEEEEEEEE!

[@paemt6220]

Iron Eagle II...where Russians fly F4's

[@killman369547]

in all fairness it's not like they could've asked the soviet government to borrow half a dozen MiGs to film with.

[@c185pilot3]

Interesting video....background radio program noise incredibly annoying...interferes with audio.

[@XaymacaJah]

yeaaahhh haaa. victory sign to you to good friend.. haa haaaa. i use one finger to do that. aaaaanyway.... run that engine up already. show me some AB

[@Ivansgarage]

Hard time talking today, go home and have a beer, it will fix your mouth!

[@afzalrahmani7038]

Sir I do can work

[@michellepowell1956]

USA USA USA!. Yes, I was made in the USA.