Wankel engines unfortunately have no real advantages and some major fatal flaws which is why no one offers a passenger aircraft with a Wankel engine

In aviation Wankel engines have no advantages, their power to weight ratio performance is not better than other available options that are also more efficient and much more reliable

@@sandervanderkammen9230 Sure it is, it's possible for Wankel engines to produce the same power at half the weight compared to piston engines. Maybe not compared to 2-strokes in small sizes though.

@devilsoffspring5519 Reliably? *NO* The new 4-stroke Rotax is better and the Wankel engine is a boat anchor compared to GTs... No legitimate company uses a Wankel engine in a passenger aircraft.

Thank you!

I agree the biggest danger is pilot error. There’s no stalling because “the wind is suddenly from behind” when turning downwind. There is no wind relative to the flying plane (other than what is caused due to its forward movement). It might just be my interpretation but what you say you think I meant doesn’t seem to match what I was saying in the video. I was not explaining it in terms of straight flight. I think my 2D animations maybe make it seem that way. I don’t have skill in 3D animation unfortunately. My reference to inertia was in relation to gusts/windshear which is near instantaneous. Not sure if you are comparing that to inertia when turning? There will be a very small forward component of speed loss due to turning (accelerating), but at a realistic turn rate in a light aircraft this takes, what, 30 seconds to complete a 180° turn? Even at a very fast turn rate (and associated steep bank angle) the increase in stall speed due to load factor will dwarf the loss due to the inertia of changing direction. One can calculate how much that would be but it’s so negligible, miniscule compared to everything else I talked about. Other than a fun theoretical thought exercise, is it even worth covering what causes maybe a 1 knot drop in airspeed? For practical flying, wouldn't it be better to talk about staying coordinated and about wing loading (and thus stall speed) increase with bank angle (while maintaining altitude or climbing) which can make differences well into the two-digit knot numbers? My opinion at least. Anyway I suspect we are possibly saying something very similar.

Why are we trying to consider anything besides the aircraft and a slice of the column of the air that it is flying within? As the aircraft is flying through the air a force called drag (sum of induced, parasite and form) acts upon it as the air resists it motion. The wings generate lift by acting upon the air, for a given wing on a given aircraft, the lift force generated will be a function of the calibrated airspeed and the angle of attack. The aircraft's motion through the air is relative solely to the air and the motion of the air relative to the ground does not affect the airspeed and therefore does not affect the lift or the drag. The aircraft is banked it uses a lateral component of lift as centripetal force to curve its flight path. As stated earlier, the lift is generated by the wings acting upon the air the aircraft is flying through. The air acted upon by the wings experiences a force opposite that of the lift. There is no other force acting upon the aircraft that is a function of the speed of the wind over the ground at a given altitude. There are numerous situations where forces act upon the aircraft due to wind gradients. These can result in pronounced and abrupt airspeed and performance changes. These can come from rising or falling columns of air, vortices, air density changes, frontal boundaries, storms and inversion layers that tend to have sudden shifts in both direction and wind speed separated by a small vertical distance. Most people will refer to this experience while flying in an aircraft as "turbulence".

There is a fundamental error here: "In a downwind turn groundspeed (inertial speed) increases due to a centripetal component of the aerodynamic force and the angle of drift." "Inertial speed" changes with the centripetal turn force, but not with the wind drift. We have already established that there is no change in inertia relative to the wind drift. So, the inertia change relative to aerodynamic effect is no different than the case of no wind.

@@davetime5234 The centripetal force acts normal to the air-velocity. The angle of drift means that there is a component of the centripetal force acting in the direction of ground-velocity.

@@colingtaylor2158 "centripetal force acts normal to the air-velocity" Yes, centripetal force acts normal to relative air velocity: but air velocity relative to the aircraft, not air velocity relative to the ground. Acceleration (here the only acceleration is the centripetal acceleration), is independent of the velocity reference frame. Because there in only centripetal acceleration (which is in a normal direction, that is, an acceleration at a right angle to the aircraft's direction of motion within the airmass): There is no acceleration in the aircraft's longitudinal direction within the airmass. Translation of the above: the aircraft has no change in airspeed from a turn to a downwind (as set out by Lets Go Aviate's main theme).

Quote "Now if we repeat the exact same exercise with the conveyor belt moving at a steady pace, I think we can all agree that if the same actions are performed, the car would also end up at the same speed in the opposite direction. " <- that is clearly wrong. You need to learn what an inertial reference frame is. That's where newtonian physics applies. If you don't understand that you will calculate nonsense. Even in your though experiment the question would be what reference frame? To earth the car would clearly have a different speed which is exactly why the downwind turn is not a myth but a physical reality.

​@swunt10 for a supposed engineer you seem to have a lack of understanding of the difference between the terms speed which is a scalar and velocity which is a vector. Just lay it out in your language as an engineer. Believe me I will be able to follow you all the way if you show me your work. You're just a troll buddy and it's obvious that you're just repeating whatever you found on Google like that attempt at bringing in a reference to the Coriolis effect. Good day!

​@swunt10 for a supposed engineer you seem to have a lack of understanding of the difference between the terms speed which is a scalar and velocity which is a vector. Show us your engineering prowess and lay it in your terms as an engineer without dumbing it down for us. Trust me, I will be able to follow right along. You are, after all, the one claiming to be an engineer not us "morons" as you called us. I can't take your position seriously when you open with the aircraft having departed controlled flight as it initiates the turn. You have already violated the parameters of the experiment and then claimed the conclusions of others are therefore false. The aircraft must maintain controlled flight throughout the turn without increasing power while it turns from headwind to downwind. It cannot make a turn that exceeds the ability of the aircraft to maintain controlled flight as then it is no longer "flying" and instead an object moving through a mass of air. Those are two very different things and at the very core of our disagreement. If you can't see that, then I'm must concludes that you're just a troll buddy and it's obvious that you're just repeating whatever you found on Google. For example that attempt at bringing in a reference to the Coriolis effect which does not apply for an object moving on the surface of the earth. Next thing you're going to tell me is that an airplane on a conveyor belt moving opposite the aircraft's direction of forward travel in excess of its takeoff speed will stop the aircraft from taking off. LOL Good day to you!

@@swunt10 Deleted my original reply. I'm content to fly my aircraft as I always fly it with the *knowledge* that this is indeed a myth that some cannot let go. I know it won't and does not stall while safely and easily doing the very things that you insist cannot be done. That is okay and I'm at peace with it, it's no skin off my back and I'm am too low of stature and qualifications to dare to tell you otherwise. Have a great day! PS Refresh your knowledge on the difference between a scalar (speed) and a vector (velocity). You should already know this as an engineer. After all an engineer should be precise in their use of terminology and I simply cannot believe that an engineer like you claim to be could so easily overlook such things. My terminology was intentional and I expected you to catch on across multiple comments. PPS Changing the frame of reference would not alter the conclusion (the downwind turn is a myth). Changing the frame of reference would only change the velocities input and the velocity output as those would be relative to the frame of reference. How much more softball can this get?!

@@swunt10 "the car would also end up at the same speed in the opposite direction. " "<- that is clearly wrong. You need to learn what an inertial reference frame is" To an adequately trained engineer that is an unnecessarily pedantic criticism. I know exactly what he meant and the effect on the relevant reverence frames. "To earth the car would clearly have a different speed " Yeah, that's why the solid distinction in the wider dialogue between ground speed and airspeed. Airspeed is the moving reference frame relative speed. Ground speed is the Earth reference speed.

If winds gust, this is a risk. But to the extent winds are steady, there is no such effect.

I'll bite! You are performing a 360 degree turn at a 20 degree bank at minimum airspeed with the stall horn sounding at a constant altitude. Winds aloft are steady at 30 knots. What happens to your airspeed as you turn? What do you need to do to at each point in this turn to maintain altitude and complete a full 360 turn? Let's assume you are in a C172 configured for slow flight, it is trimmed and already in the 20 degree bank. The stall speed is 40 knots and you are maintaining altitude at a steady 42 knots indicated with the stall horn sounding. You begin the turn heading directly into the wind... This is a standard maneuver that any student for a private pilot certificate must be able to perform and must be able to continue to perform during a flight review, so you should be very familiar with this.

@@oracle427 All aircraft can be stalled at any speed but only one critical angle of attack, (AOA), this little exercise both you and the content creator presents, ignores this absolute fact. The issue has absolutely nothing to do with either indicated or ground speed and everything to do with critical AOA. As the nose of the aircraft deviates from a direct head wind, one will have to be constantly compensating for gradual loss of lift, for any given airspeed and being most pronounced with direct tail wind. Increasing AOA at such low speed will bring on a very abrupt stall. One can apply more power to compensate loss of lift and decreasing altitude, but if the stick is pulled back, (increase in AOA), it will stall. Bear in mind many simple aircraft, Cubs, Champs, etc, lack the power for such a compensation. The butterfly in the car analogy is false in this context. The aircraft must maintain stall speed plus wind speed to remain airborne and that requires a surplus of power. I have personally experienced a sinking aircraft in such a situation and know pilots lost as a result of being caught unawares.

​​@@waynetokarz174 I'm sorry but your response does not address my question at all. As you should know very well with the setup I gave, you as the pilot would need to take no action whatsoever to maintain flying airspeed and avoid a stall and the aircraft will turn round and round all day no matter what the winds do as long as they remain steady with no gusts. This can easily be proven be actually performing the maneuver the next time you go fly. If you have any doubt about it, you shouldn't after doing it. Parts of your response are correct, particularly with respect to the critical AOA, but your aircraft will not lose airspeed as it turns downwind in steady wind conditions, that is the myth. This is what is taught as part of a become a pilot. In fact what is taught is how gusts and windshear due to various environmental conditions can result in a sudden loss or gain in airspeed and can result in unrecoverable loss of altitude at low altitude. That is why we are taught to add a gust factor in gusty wind conditions, but there is no such practice for a steady wind, because it is completely unnecessary.

​​@@waynetokarz174 I suggest you should review chapter 12 of the Pilots Handbook of Aeronautical Knowledge. You also did not answer my question, so I'll go ahead and answer it for you. The pilot would need to do nothing at all in steady winds and the aircraft will turn round and round all day long despite turning from headwind to downwind and every which way. No power changes, no control inputs, just let it fly. Yes airplanes always stall at the critical AOA that had nothing to do with the fact that pilots believe this myth. I can't fault non-pilot enthusiasts without training.

​@@waynetokarz174having read your response again I just realized something. I think you believe that an aircraft with a "tailwind" is flying at a higher AoA than the same aircraft flying into a "headwind". This is not true and the aircraft is flying at the same AoA in steady flight in either the "headwind" or "tailwind" because the aircraft is not experiencing either of those in steady wind conditions while airborne.

AOPA, wow that is unbelievable, and is unfortunately part of the reason people believe it. The problem is if a pilot thinks the downwind turn is dangerous because of inertia or whatever, then they don't understand the real dangers of the downwind turn (windshear/gusts, speed illusions, reduced angle of climb etc. mixed in with the higher stall speed in a bank) and are thus potentially placing themselves in danger. Half of being safe is knowing what dangers to look out for. The "on the step" myth is one I've been wanting to tackle for a while.

@@swunt10 Oh dear, here we go again. Will it ever end? I daresay you are a good engineer, but are you a pilot?

@@swunt10 I've been flying for 40 years - and I have lost count of the number of times that I have tried to convince people who believe in this myth. So, against my better judgement, I will wearily try again. You make the mistake of considering the physics of an aircraft in flight in relation to the ground. The ground is completely irrelevant once the aircraft is airborne.

@@swunt10 Actually, pilots do study physics to gain their license. They must understand Newtonian physics and Bernoulli's theorem, in order to understand how a wing generates lift. The gyroscopic precession of propellers is also taught. You are employing the incorrect physical model. An aircraft does not behave like a vehicle on the road, when changing direction. The ground (and all the physics you cite) are utterly irrelevant to an aircraft in flight. You seem to think that an aircraft pivots about a vertical axis to change direction. It does not. Instead, it moves though an air mass which is itself, also in motion. If you think about it in that way, you will see that the originator of this video is entirely correct - and you would be hard pressed to find a flight instructor who would disagree with him. Imagine an aircraft flying at a constant speed above cloud, using his instruments to make a constant rate turn. He and his aircraft, experience a circular flight path, like the circumference of a circle. However, if we were to watch his flight from his ADS-B GPS returns, we would see a spiral track, moving downwind. Nevertheless the aircraft, which experiences only relative airspeed, behaves precisely the same whether it is flying into the wind or downwind. The downwind turn is only risky if the pilot is not relying upon his airspeed, but is instead looking at the ground and judging his speed from that. Grave mistakes such as this are demonstrated to a student pilot in their initial training. Many seasoned and much admired professional flight instructors, such as Paul Bertorelli, Ron Machado (ATP) and Peter Garrison (who has designed and built two aircraft) have each written about the myth of the downwind turn. Indeed, they have each expressed such frustration at the persistence of this myth, that they are inclined never to write about it again. A feeling which resonates with me!

​@@rigilchristVery well said! I offer to add a little and certainly not take away from anything that you said. The wings of an aircraft in level controlled flight generate a lift force that one can assume to be opposite to the force of gravity in level flight. When an aircraft banks to make a turn a lateral component of the lift force acts as the centripetal force and accelerates the aircraft into a turning path. The lateral component of the velocity will continue to change direction while this lateral lift component exists. The aircraft will rotate due to the aerodynamic forces acting on the wings and stabilizers. How an aircraft turns is something that is taught to all pilots at this level of detail and this has been well understood for over a hundred years now.

I do, just about every takeoff I do when staying in the pattern. If there is no wind or 20 knots wind I remain at Vy speed from upwind, through crosswind, onto downwind. My ASI keeps reading 60kts throughout, every time, regardless of wind speed.

Charles, you should try flying a sailplane and do some manouevring in wave lift in a 50 knot wind and a 50 knot airspeed. Clue: your airspeed does not slam from 100 knots to zero as you turn. Of course, your GROUNDSPEED does, but the glider flies without reference to the ground

Almost every pilot at some point in training will be asked to fly a turn at minimum airspeed in a 20 degree bank. Many small aircraft stall at approximately 40 knots. Now I've actually done this in wind aloft at 30-40 knots yet somehow the aircraft didn't stall despite being at an airspeed of about 42-45 knots the entire time. I never added power at any point in the turn and the airspeed remained constant. This is a myth and this video is spot on.

True, He is compensating with engine power to maintain/ accelerate to 60 indicated. Gliders maintain/ get back to these safe speeds cause of low drag. He shouldn't try this thoery in a sluggish airplane above stall.

​@@LetsGoAviate excellent video and judging by all the comments, it's clear that the myth remains alive and well!

I think that makes logical sense: the IAS doesn't change from the turn across the wind direction, but the apparent ground relative motion does change. So overly steep turns in reference to external ground reference is a risk.

Disagree , Climb performance into wind remains unaffected. Ground speed decreases . Landing downwind , then you have to reverse wind gradient ! (please try ) You tend to increase asi close to the ground . But ground speed increases . Trust the instruments. Not what it looks like .

@@marks2749 instruments can lie, asi is strictly an indicator and does not show AOA, for the ASI to indicate safe flying speed downwind, you will require an increase in throttle. You obviously have not performed downwind landings.

That has to do with your response to ground cues. Same with airplane pilots. People increase their bank and pull harder to make their turn and end up stalling. It's not due to the wind alone, it's the pilot's incorrect response to what the wind does to his pattern positioning.

​@@Dr_Kenneth_NoisewaterDo you fly? Perhaps you could show our poorly inexperienced souls first hand how not to crash in a downwind turn without adding power.

​@@Dr_Kenneth_NoisewaterIf this was true then there'd be no such thing as stall induced wind shear.

Two options: 1) lower the nose sufficiently to maintain speed 2) be going fast enough at the start that you don’t burn off so much speed in the turn you get into a dangerously low speed on exit.

​​@@charlesmyers9765 this makes zero sense and no pilot would add power as they turn downwind. This is not necessary and not taught to anyone. How would one add power anyway during takeoff? In most small aircraft you are at maximum power for takeoff when turning downwind. An aircraft at minimum airspeed just above a stall can still back to 20 degrees and turn all day long at a constant power setting and maintain a steady airspeed despite being in a steady wind aloft. Of the aircraft is only 2-3 know above stall speed then based on your logic almost any gentle wind would immediately result in a stall as the aircraft turns downwind. There is rarely a day where winds aloft are less then 15 knots at pattern attitude. Almost every student pilot will need to demonstrate this during training. It is optional for a private pilot rating, but most instructors will teach it anyway. This contradicts what you are saying and confirms that this is indeed a myth.

perfect answer

By the following: "Full-scale airplanes take long enough to turn that they can speed up or slow down to maintain a constant airspeed as they change direction" Are you implying that with a constant downwind, that any speed change is imposed on the pilot due making the turn to downwind? (where the airplane changes orientation with respect to the wind direction over the ground?)

@@davetime5234 no, I am not. Ones speed and direction over ground is always irrelevant, (except to navigation calculations), there is no speed change imposed upon the pilot. Both tail and headwinds are not absolute in the velocity frame, therefore during the turn a lack of excess airspeed will be noted as a loss of lift, which translates to a loss of altitude. This now sets the pilot/aircraft up for potential loss of control. Technically, if during the turn, a loss of altitude was experienced, the first indicator of loss of control has already been experienced.

@@waynetokarz174 I'm not sure if I'm interpreting this correctly?: "Both tail and headwinds are not absolute in the velocity frame" In the airspeed frame, in the case of a steady wind, there are no tail winds or headwinds, whether turning or not(?). In the above case, there is no change in airspeed due to wind during a turn. But of course, the turn requires more lift, so more angle of attack, and the drag to produce that lift. So, the increased lift to turn the aircraft will decrease airspeed. And if that extra turn lift's (drag induced) airspeed decrease is not arrested by thrust, then assuming trim at the prior airspeed, the nose will drop to acquire that speed from altitude loss? So, there is no effect from wind you are now saying (in other words, the same thing happens in a turn whether there is a steady wind or calm conditions)?

@@davetime5234I’m sorry Dave but I am not able to follow your comment. A lot of people are applying pure theoretical physics to the topic, whereas in the real world there are factors not being raised here. For starters the theory applies as an instantaneous event while in reality there is a huge time lag between cause, effect and reaction. The airplane has to catch up to the air. Failure to allow for this lag coupled with slow or improper control inputs will result in a downwind turn stall. People on here are beating theory to death while failing the two simplest proofs, GO FLY IT! Look up accident reports. Crashed planes don’t lie.

nope, AOA is absolutely the only thing that matters.

@@waynetokarz174 AoA is perhaps the ultimate thing that matters, but hardly the only thing that matters. As long as your load and density altitude are within limits and you don't make overly abrupt pitch changes, indicated airspeed is a good proxy for maintaining AoA within limits. I assume that when he stated indicated airspeed matters, that in choosing between IAS and GS, it is IAS that matters.

Totally correct! FI here.

I did 45 degree turns for my checkride in the pattern. If you aren't trying to maintain altitude there is absolutely nothing wrong with steep turns, infact, sticking to 20 degree turns will make you more likely to try and drag the nose with the pedals and get yourself into a spin.

While there is nothing wrong with a properly executed steep turn in general, the key point is that you are increasing wing loading compared to a shallower turn and in the pattern you will already be fairly slow so you are reducing your margin above the stall. Also aggressive manoeuvring in the pattern isn’t great.

@@speedbird300 And you are pushing closer to the stall AOA, as coaxing greater lift from the wings at a given airspeed for the turning force, adds to the AOA already needed to oppose weight due to gravity. Two safety margins you are pushing against: 1)spare AoA left before the critical AoA 2)low altitude (less potential energy "reserve" to recover)