Vmc or Die 

After flying 34 years with the airlines, including five years with Turbo Props and various narrow body jets, I have yet to hear an instructor explain these procedures as well as you have…. I have enjoyed each and every video.

Best 14 minutes on piston twin principles on YT…You out did yourself brother….Thanks🙏🏼✈

I figured that I better add a quick comment. Vmc definitions focus on rudder authority, not aileron authority, but they’re really two sides of the same coin. I didn’t really explain that in the video…

As a retired Australian flight instructor with multiple twin ratings including Cessna 300 and 400 series i am amazed at how many VMCa accidents happen in the US. I saw your reference to not empasising the importance of rudder but I feel I should make some points. So for the inexperienced pilot who read this..... The problem with an engine failure in a twin is asymetric thrust. This thrust produces yaw. You correct yaw with rudder, not ailerons! The C310 has a VMCa about 80kts. It has a best rate of climb SE of 106kts and a best angle of climb of 95kts. You should be NO WHERE NEAR VMCa! The way to avoid VMCa is with AIRSPEED! Not ailerons! Not angle of bank!. The aircraft WILL be sideslipping because it is producing asymetric thust! What is important is holding a heading and preventing un-wanted yaw. It is correct that if you get below VMCa you MUST reduce power on the good engine. Once power is reduced you will regain rudder authority. Nose attitude controls air speed so you must lower the nose and regain airspeed to 95 kts at least and re-apply power. RUDDER prevents yaw not ailerons. The 5 degree angle of bank is not to save you from VMCa, it is to improve climb performance once you are in control and have achievedd 106kts. It is obvious to me that VMCa is NOT well understood or well taught in the US, if it was there would not be so many fatalities because of this. My first twin endorsment included a VMCa roll over demonstration with the appropriate recovery method. This was obviously done at altitude. I can assure you this demonstration remained firmly fixed in my mind. I suggest all twin pilot go out with an instructor and do this exercise if you have not already done so. IF you get to VMCa, you are going down! You must remain in control by reducing power and lower the nose to gain AIRSPEED! In a twin, AIRSPEED is KING! If you are anywhere near VMCa with an engine out, you are "behind the power curve", you will NOT be climbing, you will NOT be maintaing height, you WILL be going down! Look for the blue line speed and fly it REGARDLESS! Holding it straight, identifying, feathering, cleaning up the aircraft are all priorities before worrying about 5 degrees angle of bank!

The goal with one engine inoperative is zero sideslip. A yaw string on the nose was a teaching aid a local instructor used.

Nice Video. I fly a C414A and can confirm what you said. I've experienced two engine failures (one in a C340 other in a 1975 C414) and there is little performance there. I do a lot of low alt engine failure practice on X-Plane and agree it's closer to reality. Nice job!!

There’s a lot to considering when you’re 45 seconds into the air and the ground is coming up fast. Great video.

Excellent video and explanation. Only issue I have is about Vmc having to do with ailerons countering roll when it's actually rudder, but you did mention this somewhere in the comments. Being from the area, this crash hit close to home. And being a multi-turbine instructor, I am going to try incorporating this video into our single-engine courses. Vmc or Die is a perfect title.

Really good video. I do think they are safer for the pilot with the right mindset and training however. I fly a 3 engine big jets as a captain and I own a baron, I have to remember that if I lose one in the baron sometimes straight ahead is the best option, and I need to think about it more like a power loss in a single. I separate the 2 in my mind. It is not gonna fly out like a jet, and V1 is basically blue line in most situation. I tried this out hot and have in MSFS out of Santa Fe after watching your last video, and it’s a bitch. Once or twice I just ended up with an off airport landing. I took off out of Oshkosh yesterday in real life eastbound at max gross weight, and briefed that if we couldn’t land straight ahead and it wouldn’t fly I was gonna nurse it over the houses into the lake just off the end. I also agree about xplane having a better flight model and handling more realistically with an engine out. If you ever need help with the videos let me know. I think your channel is gonna go far.

SO well done. I knew asymmetric thrust was bad, but it's really BAD in a conventional twin. Stuff I never knew. One word - Skymaster. Wish I could afford to spin two props.

I would say that an extra engine DOES make you safer for the most part. There are some caveats though that can get you in trouble, especially at slower speed, i.e. taking off or landing. Here you can get in trouble for sure if you are not ready or proficient.

Every twin owner should routinely fly with a multi engine CFI and practice engine loss at altitude. Muscle memory is so important!🙏

Very well done…. I’ve have been fortunate to fly/own a Aerostar 700. With one engine (loss of one), it climbs out at 660 ft. But, you can’t be stupid with overconfidence.

the algorithm just suggested this video to me and i really enjoyed the in depth explanations.

Fascinating and yea I wouldn’t put myself in a twin that has a critical engine namely both have to be counter rotating, and secondly doesn’t have an auto feather Too much to worry about when things go south and very rapidly.

Thanks for all the information you provide in your videos. I really appreciate learning about things like this.

Great video once again. I really appreciate these videos. Keep up the good work

Ive watched a few great pilots flyibg twins get in front of the power curve when loosing an engine on takeoff. 1) pick longer runway you can get to 10 knots faster on rotate. Closer to blue line speeds, Never rotate early. 2) dont use flaps, one less step in procedure, choose longer runway. 3) gear up 5 ft above ground. Thats 2 steps left out of procedure during engine out. Removed flaps & gear up steps immediantly. Plus less drag. 4) throttle, props & mixture are most likely set duribg take out so less to think about in emergency. All are full forward already. 5) pitch for blue line, raise dead on engine 5 degrees, split the ball using rudder. 6) then identify, verify by pullibg throttle on dead engine to idle, feather dead engine & pull its mixture off. Lastly turn off fuel pump, adjust crossfeed fuel. ⛽️ Either land off field straight ahead best option even gear up & survive landing.

Your attention to detail in explaining the effects of asymmetric thrust as amazing. I never thought of the trained use of rudder, and how it is adversarial in this case. The Santa Fe accident scared me (I fly a 310R), particularly because the pilot must have been a great stick&rudder, but you may have a point. That said, it was a turbo, so would it not have had more climb performance at 9000 feet density altitude, even with average technique. The NTSB will report if the failed side was feathered, and if that remaining turbo was operating.

Good explanation, Im keeping my 337.

I appreciate you sharing your knowledge

A stellar voice in safety and fluency, you are making the air safer with each video. Thank you

I have several objections with the concepts as explained in this video. Here a few of the most important iones. The ball 1/2 width off center is not "uncoordinated flight". Coordinated flight means zero sideslip angle. When there is no net lateral force, coordinated flight is equivalent to the apparent gravity vector being perpendicular to the wings (which is what the ball actually measures). But that's not the situation when you have asymmetric thrust. Certainly, when you have asymmetric thrust you want to counter the thrust yawing moment with rudder. However, the way the rudder applies yaw moment is through a lateral force on the fin which creates an unbalanced lateral force. So what happens next? Perhaps it's easier with an example. Say that the right engine fails. Initially you have an unbalanced yaw moment to the right that you will counteract with left rudder. The left yaw moment achieved by the rudder is via a lateral force to the right on the fin. Because of that unbalanced lateral force, the plane will start to drift to the right/ Because now the wind hits the fin a bit from the right, that will tend to create a left force which in fact will be felt as a reduction of the right force previously mentioned, which in turn reduces the left yawing moment initially achieved with the application of left rudder. So you are not fully cancelling the right yaw anymore. You will need to add more rudder. If you were going slow and you were already applying all the rudder you had, too bad, you don't have more rudder to add, you just lost control of your plane. So is there a way to cancel the right force on the rudder so we avoid the sideslip and the need to add even more rudder? Yes: Bank to the left enough so as the left horizontal component of the lift vector equals and cancels the right force on the fin. In this way, you can keep zero sideslip and a zero net yaw moment with the original rudder input. THIS IS WHY VMC IS LESS WHEN YOU KEEP A BANK TO THE GOOD ENGINE. YOU NEED LESS RUDDER TO ZERO THE THRUST'S ASYMMETRIC YAWING MOMENT. VMC DOESN'T HAPPEN WHEN YOU RUN OUT OF AILERONS TO KEEP THE WINGS LEVEL. IT HAPPENS WHEN YOU RUN OUT OF RUDDER TO ZERO OUT THE YAW MOMENT and your plane yaws and rolls (as a result of the yaw) out of control. Note that if you bank the plane to cancel the later forces, you will be flying in a bank but with net zero lateral force and with zero sideslip. THIS IS THE REAL COORDINATED FLIGHT. Yet, the ball will "fall" a bit towards the lower wing because you are banking but not turning. But if you pout a yarn in the middle of the windshield, the yarn will be completely centered. This applies to all airplanes, prop or jets. There are a few differences between prop an jet, yes, but this is not one of them. This is just rudder compensating the thrust's yaw moment and bank compensating the rudder's unbalanced lateral force. The source of thrust is irrelevant. The differences between jet and prop are: a) In a jet you don't need to maintain aileron input to maintain this status. You are in coordinated flight (even if the ball tells otherwise) and the lift is symmetrical. In a twin prop the working propeller will be blowing higher speed air over its wing which will then generate more lift so you will need to maintain aileron towards the good engine to keep the bank constant. b) Other effects of propellers (like torque and p-factor) will make that you will need more rudder and aileron to compensate the loss of the left engine than the loss of the left engine. Those effects don't exist in a jet. c) Most jets are required and designed to have an engine failure during the take-off roll at about V1 (which is typically before Vr and before lift-off) and still be able to maintain directional control on the ground, accelerate to Vr, lift off and accelerate to V2 which is the minimum speed you should keep in the climb after losing an engine. V2 is typically much larger than V1. The rudder is design to maintain directional control at V1 and, because the effectiveness of the rudder goes with the square of the airspeed, by the time you reach V2 you have plenty of rudder authority so the bank technique is not really critical. V2 is well above Vmc. In a prop twin, Vmc is Vmc so if you are flying at Vmc you have ero margin, you NEED that bank to maintain control, and the blue line (the minimum speed you should keep when climbing on a single engine) is typically not much higher, so you have margin but not much, so the bank technique is still critical. Finally, I don't know where you got that wrong notion that Vmc changes with weight. Unlike the stall speed, it doesn't. And the reason why one does and the other doesn't is easy. Lift counteracts weight, and weight depends on weight. Rudder counteracts thrust yaw, and thrust and it's lever arm do not depend on weight. What does depend on weight is how much bank you need to keep the zero sideslip condition. The heavier the plane the larger the lift so you need a smaller bank to achieve the same horizontal component of the lift.

Fantastic explanation. Thanks for taking the time to do this.

Very professional presentation.

VMC roll is caused by P-factor as much as it is asymmetric thrust. P-factor is why it's worse to lose the left engine than the right engine. The down-going propeller blade takes a bigger bite of the air and therefore, pulls harder than the up-going blade..

Awesome explanation..thanks

Great explanation...thank you.

Further to my last comment, I would recommend that every pilot read 'Stick and Rudder' by Wolfgang Langweisse. This has been my flying bible for 30+years and although written in 1930 it is very relevant with all aircraft. A thorough understanding of flying the wing which, is all you are doing really will save a lot of lives and misery. Too many treat it like driving their car and an instructor or pilot that has that mindset will crash

Best explanation of the topic I've encountered anywhere. Got yourself a new subscriber. Thx!

The idea behind the twin and safety assumes that you are properly trained and have the experience to handle a twin engine, and complex (constant speed prop, retractable landing gear) aircraft. If properly trained the twin provides a safer flight. The buffalo and the "pusher pull you"cessna" are exceptions given their single engine performance.

Excellent. This is mind-blowingly well prepared and explained.

Excellent, fascinating and informative. Nicely done buddy.

I think I see your point. The 5* angle of bank toward the good (let's say, Left) engine serves to balance the plane so it will fly essentially straight through the air. The ailerons will however, create a (add to the) starboard yaw that must be countered with slight rudder.

I've seen a 402 take off , lose one engine , then a few seconds later went into a Vmc roll.Confusion as to which engine died was chaotic as I was later told , the pilot brought the working engine to idle , recovered from the roll , landed straight ahead and wrecked the Airplane. The four occupants survived. A lot or recurrent training would have prevented this but at the end ,the passengers and pilot are still around. Great tutorial by the way ! thanks !

Do a booklet on these concepts as described by you with lots o illustrations please?! Third time watching and still taking notes! Bravo 🎉good sir. Thank you.

I seriously appreciate your videos sir!!

Excellent! Like John, below I am also a long time guy who is now spoiled because I fly jets. We don't even consider many of the points in this video because we have so much power available. Yes, the plane needs to be trimmed out for the engine out situation but we don't think twice about turning into the good engine. We just trim and fly. Not so when I flew the Dash8. Plenty of power on that plane BUT the massive props way out on the wing coupled with the massive rudder meant that you had to get that thing trimmed out right in order to relax on one engine. This is an exceptional video and should be required viewing annually by anyone who flies a light piston twin. Or, a fully loaded and heavy King Air, etc.

Thank you well explained. You've got another subscriber !!

This is one of the best videos I have I seen.

Superb, nice contrast and complement to blancolirio who deals with stall spin accidents all the best. Nice work!

Expert analysis. Been a long time since I flew single pilot charter in my turbo twin Comanche. No one gets enough exposure to this kind of critical performance training.

I received my multi-engine rating in a Piper Seneca with counter rotating props vmc was fairly minimal but while training with a Piper Navajo with turbo engines I had to demonstrate vmc and recover. Then my instructor feathered my left engine and did some air work and turning into the dead prop I had to make a landing with the left engine shutdown and making normal left turns in the pattern. All very stressful even with the instructor along. Think what it would be like IMC at night! I flew that Navajo many many hours and thank GOD I never had a engine failure. I do think counter rotating props do help a bit with the VMC problem but there is a Macho feeling out there with pilots. Trouble flying a twin one one engine? Then fly a single! I did saw a demo pilot flying a souped up Navajo do a left engine feather on take-off at 25 ft agl Ever see Bob Hoover fly his Aero Commander he was the VMC expert!!

Hello, very well done. The accident reports are still full of VMC accidents in twins. I too practice engine out procedures on FS2020 and XPlane 12. It does train your thinking enough that reacting to an engine failure becomes automatic after Sim practice. I sometimes look off to one side and then fail the engine to simulate it being a "surprise". No one should fly light twins without being ready to properly handle the airplane on one engine. Thanks.

Excellent video for the Pre-Student!

I flew the exact profile and executed as accurate the scenario reported on the 310 crash in X-Plane and was unable to recover 4 out of 5 times - funny thing is the successful flight was a result of leaning in to the good engine - I had very few options that I could notice in the struggle in that scenery and it was a handful from the get go, it made me feel so sorry for the PIC it was a horrible situation he could never be adequately trained for.

Superb explanation of a complex subject!

Absolutely brilliant explanations. Best I’ve read, seen, or heard; ever. Good lord brother, not all of us are so goddamn bright 😅 Could you talk a little slower for those of us on the average part of the spectrum?! Thank you for considering. What a treasure to find your channel. I’m watching this video another four times.

Thinking about aileron authority, slight sideways flight path, and vmc. I wonder if the large tip tanks contribute to a loss of aileron authority by disrupting airflow slightly over the aileron given a slightly sideways flight path? Not saying tip tanks caused the crash, but Im wondering if it might of contributed or if a wing clear of tip tanks would have performed slightly better?

WOW, so far above and beyond the textbooks! A little clean-up and editing, and license this vid to Flight Safety Int'l/Sporty's/etc. 👍👍👍

Hi ,at the 11.42 clip, I would like to ask, Could use a hobby model ,to demonstrate the maneuver your explaining? Or use vr to show us the maneuver? Thanks

Only recently came across your excellent concise, data dense channel. Thanks for your work.

That Was Really Great! Surely You're A CFI Or Lecturer At Some Aviation School. What's Your Take On Counter-Rotating Engines In The Same Situation? Thank You.

Very informative thanks. Off to X plane to try it out and see if I can do the 5 deg bank 1/2 ball. Should be a challenge. Find flying the Barron 58 a challenge anyway. 😅😅😅😅😅😅😅😅😅😅

I used to read aviation consumer back in the 80's and they had an article about the Cessna 414 where the company hired the best pilot they could find to fly it on one engine and sure enough, it ended badly.

Two engines doubles your odds of an engine failure. So, for it to pay off, it needs to double your chances of avoiding a crash landing. There seem to be a lot of twin crashes so I am not so sure it really improves the odds.

Great job

A1 video!

Glider pilot here, and I don't understand. Skip if you wish. So, does the typical twin generate significant adverse yaw from the aileron that is pointing down (which has a long moment arm - being out on the end of the wing)? If so, then banking into the dead engine increases the adverse yaw into the working engine, lessening the rudder input required to keep the aircraft from turning into the dead engine (because the dead engine side is cleaner)? It would seem there is little margin before a roll into the dead engine begins, even though that side is cleaner (from the wing's perspective, not the engine's). By modulating a relative slip into the working engine, with a little rudder into the working engine, one would have a hard time turning into the working engine. Of course, the airplane wants to turn into the dead engine.

I’ve not flown a twin. If I lost one engine at low airspeed, I’d reduce power and push the nose down to gain AS and aileron control, then bring RapM’s up. I think that if I was close to the ground and slow on takeoff, I’d dial in just as much power as the controls could handle. If this was not enough to climb, it would at least extend my glide and options.

Wow. Regardless of how right you might be, getting all this straight, after you’ve already lost 20 IQ points merely by sitting down in the left seat… and then having to overcome several seconds of startle factor… seems like a nearly insurmountable task. I’m wondering if it might be best to pull power on the good engine (probably psychologically impossible, never mind the time spent identifying the good engine) and fly into the crash.

WOW awesome. did you ever read the book stick and rudder? what did you think of it?

Great video

I think that, even though it may be true that banking into the dead engine can be done in very controlled circumstances, and knowing that pilots will always take the easy way out in a desperate situation, I don't tell people it can be done, unless they are going to die if they don't. Once you plant the seed of turning into the dead engine is ok, someone is going to get killed.

Too many words. What was the failed engine short list? Trim Rudder towards the active engine, active engine wing down 5 degrees while using attitude to control speed and feathering the failed engine prop?

Good luck on the turn into the failed engine. Is your experience purely on MS training aid?

Is VMCA speed determined only at full power on the operating engine? Great video thanks!

A question. Blue line represents Vyse, but doesn't that assume that you have excess thrust available? In a situation where you can't maintain altitude single engine at Vyse, could an airspeed closer to minimum drag possibly allow you to maintain altitude, and how does that speed compare to Vyse?

You were soo close. Vmc is when "the Rudder" looses directional control and the plane yaws due to lower air speed & asymmetrically thrust from operating engine. One wouldnt want to use ailerons input during a stalled plane with yawing tendencies. A plane will not Spin when stalled if it does not yaw. One needs both stall & yaw to spin. Last but not least is in light twins its not just stall or a spin or a wing drop but VMC ROLL. This is when the twin pancakes, rolling inverted onto itself if below red line on airspeed indicator & rudder authority is lost.

Thanks!

You have lots of good information here, but there are also several inaccurate statements. A few of them are: Coordinated flight is possible and desirable in OEI flight, but it requires a yaw string to find it. And, more bank is not better, and most aircraft 3-4 degrees is the optimum bank angle, 5 degrees would be too much.

Find the best scene for the crash ....i like that one

Just watch Bob Hoover, and smile. 🙂

Going below VMC doesn’t over power Aileron authority, it over powers rudder authority.

Really great explanation. I would agree with one of the comments below, "best 14 minutes on piston twin principles on YT." Great job

Probably have to watch this 100 yimes to get it straight.

I see. Nothing new for me. At low speeds (high AoA) It is better to use rudder pedals to roll. Because using ailerons may cause the assymetrical stall.

I’m not sure your explanation of the effect of higher weights is correct. In steady state flight, inertia effects are zero (no acceleration). Rather, at higher weights, in a bank some of that weight is counteracting the force from the rudder defection, reducing total lateral load for the same rudder deflection, or looked at another way reducing required rudder defection for the same amount of side slip.

Ailerons have nothing to do with it RUDDER stop the yaw this will stop the roll Slight bank towards the live engine will help performance but always control with rudder first

Running engine takes most of em to the point of impact. Raise the dead!! - Mr Addams, Addams Family Pinball circa 1994-ish

If rolling over, kill the good engine and nose down and you MIGHT still die. Don’t kill the good engine and lower the nose, you WILL die.

“VMC Spin”? Oh for goodness sake, the VMC issue is NOT a spin and the loss of yaw/roll control looks NOTHING like a spin.

Just hope it never happens to you.

Watch Probable Cause Dan Gryder - Suprise Multi-Engine Vmc Rollover - Ride Along on This! // Watch ALL on AQP Ride Along Videos! PLAYLIST //

2nd engine DOES, just not when it's not working lol

It's an issue that always vexed me. However it would be very insttucted and more useful if you could provide with a simpler and graphical illustration of a stationary image with the forces at wotk under such contingency.

We never hear about multi engine failures and good landings. Not news worthy.

FlyWire and Blancolirio both say twins spins are basically unrecoverable, so don't get in one. Agree? I think I do. Another video I watched made another point that uncoordinated flight with too great an angle of attack relative to the vertical stabilizer causes it to stall and that's what initiates a snap roll. Scary! ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-VcEg39NmxY4.html&pp=ygURbWFydGluIHBhdWx5IHR3aW4%3D

310 gyroscope.

It's easy to defend my comment. Your statement that VMC is dependent on aileron authority is simply incorrect. A VMC roll is prevented by countering yaw into the dead engine using rudder, rather than with aileron input. Loss of rudder authority makes the increasing yaw and bank into the dead engine impossible to control even WITH aileron input. The same applies to attempting to prevent a stall/spin on the base to final turn. Aileron input to counter the increased bank toward the low wing simply increases the inside wing's AOA and brings it closer to a stall and the aircraft closer to an incipient or fully developed spin. Far more experienced pilots than I am have also criticized your video. JF ATP CFII MEI

At seventy two you need a safety pilot no matter what. Get real. That isn't what you're clay lacey.

I disagree with your assertion that Vmc is a function of weight. First, it's not that higher weights move less, its that higher weights accelerate more slowly, they still move.. As you approach Vmc, rotational speeds are zero anyway. Second, Vmc has to do with counteracting airframe rotation, so angular momentum is in play, not linear. This means that in any rotation the airplane responds to an angular moment of inertia, not plain mass. Third, Vmc is derived from rudder effectiveness vs off center thrust. Rudder effectiveness is a function of the rudder force AND the length of the rudder arm from the center of rotation in the yaw axis, ie the lever arm. So CG location plays a factor in Vmc; aft CG raises Vmc. Fourth, Vmc has to do with asymmetric thrust which produces (mostly) yaw, and is balanced by rudder. Vmc is about balancing these two forces, and specifically when they are no longer able to be balanced. As others have mentioned, ailerons are very secondary. Weight's most pronounced effect is reducing climb performance The greater rotational inertia (if any) will only slow the rate of turn entry or turn cessation. It will not change Vmc. i like that you mention reducing thrust on the good engine to maintain control. Many teach chopping power completely, not necessary if you react at the onset of Vmc. As you begin to lose rudder authority, reducing power on the good engine will reduce Vmc. Placarded Vmc is at full power, and of course you can always change that. This is important when trying to stretch a powered descent into terrain, you have more time to choose a spot if you fly with reduced power on the good engine. By reducing power, you can bring actual Vmc to below stall speed.

Vmc ISN'T about aileron control, but RUDDER control buddy and it's NOT the minimum speed that you can control a twin at 'per se' , but only in a particular configuration which included the live engine at max power!! There are actually plenty of errors in this video and for safety's sake, it should be taken down!!

Good video, nicely explained. The second engine is the one that kills you. Have a lot of time in light twins and much in the 310. It is particularly unforgiving with the inertia from the main tanks which would likely be full if a long flight. Having said that, you are correct there is a lot of misunderstanding and not enough practice. Better to consider 'off airport' landing the right way up higher on the priority list if you get a failure as you would with a single AND practice. Jets for the last 20 years, much safer..