Newbie Vmca question
Why do it if it's not fun?
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No new debates there, DAR. I think we're all agreed that's perfectly possible. Thanks for the proof though! The debate is purely about the terminology we'd use to describe it (or the terminology we'd use to describe the speed a couple of knots lower where you wouldn't be able to maintain control.)
Out of interest... you said the stall warner was going - but how close to the stall were you actually required to get to complete your test flight profile? Asymmetric flight near the stall is something I have little experience of, and little desire to practice!
FFF
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PS - Thanks for your PM - reply coming later!
Out of interest... you said the stall warner was going - but how close to the stall were you actually required to get to complete your test flight profile? Asymmetric flight near the stall is something I have little experience of, and little desire to practice!
FFF
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PS - Thanks for your PM - reply coming later!
Moderator
the stall warner was going - but how close to the stall were you actually required to get to complete your test flight profile?
Yes, the stall warning was sounding during this element of my flight. it had started at 75 MPH IAS. I observed 73 MPH IAS while maintaining control with the left engine feathered, and right at MCP (flaps and gear up). With some reduction to the right power to maintain straight flight, I was able to fly as slowly as 67 MPH IAS, at which point pitch control could not be maintained. The first indication of the inability to control pitch, is my indication of a stall. In this case, the Navajo gently dropped the nose, but did not change attitude in roll or yaw.
I am not saying that some aircraft may not display alarming tendancies in this configuration, this aircraft did not. I was flying by myself, in the best possible conditions, with lots of altitude, no rush, and no pressure [to go around, or otherwise deal with an emergency].
This flying was accomplished in accordance with a Transport Canada approved flight test program, with many safety measures in effect. Pilots should not be "experimenting" in this phase of flight.
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You also said I don't understand what Vmca means. It's a pity you can't concisely correct my misunderstanding, rather than referring me back to the same posts that I had misunderstood earlier. Generally, when someone misunderstands something I say, I try to re-word it to help them understand.
i have also been put off flying twins for life!
A multi-engine airplane is not inherently difficult. Certain aspects of it's behavior, namely flying with one engine inoperative at low speeds, merit attention, but are easily addressed. The multi-engine airplane is not a flying deathtrap.
If you intend to fly a conventional gear airplane, then learning about handling a tailwheel is in your best interest. It takes specific instruction.
If you intend to fly instruments, then learning about instrument flight is necessary. Specific instruction is required.
If you intend to fly a multi-engine airplane, then dedicated, specific instruction is given. No different than if you intend do do anything else in aviation.
In light multi-engine airplanes, in many cases the loss of one engine will not permit the airplane to retain altitude for long, or at all. Only a few light piston twins have much of a single engine service ceiling. Think of it this way, however; you have a lot more options in the twin than you do in a single, following the loss of one engine. You've also got additional generators, additional hydraulic pumps, additional vacuum pumps, additional fuel pumps and fuel options, etc. With the twin you've got greater all-engine speed, climb performance, and in many cases, comfort.
Then again, you've also got much greater expense.
Multi-engine airplanes shouldn't frighten, but only beg for understanding. Flying one is just another trick in your bag of tricks, nothing more. The single most important thing you need to understand about losing an engine in a light twin comes into play when being slow and carrying power on the good engine, and it's drilled into you time and time again during training until it's a very simple concept to remember and understand; sometimes when directional control becomes an issue, the only remaining choice is to retard power on the good engine. Once that concept is internalized and you understand from experience why you shouldn't get too slow, you realize that losing an engine isn't really an emergency (a concept that your instructor in single engine airplanes should have also instilled). It's just another phase of flight for which you can easily be trained.
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Would one of you be kind enough to post complete simulated Vmca demonstration procedure, from initiating Vmca, to recognition of impending vmca, to initial action and recovery.
Thanks in advance.
Thanks in advance.
Why do it if it's not fun?
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Avicon,
The following is provided for information only - please get proper instruction, in an aircraft, from a multi-engine instructor, as part of an approved course!
Other instructors may do this slightly differently, but here's how I do it:
- Perform relevant airmanship actions - safe altituden, appropriate area, good lookout.
- I have control of the aircraft; however, you have control of the rudder.
- Please use the rudder to prevent yaw (using a distant visual feature as a reference, as taught on previous exercises).
- Whilst maintaining pitch, and keeping wings level with ailerons, I gradually close one throttle, expecting you to apply rudder (and trim) to prevent yaw. I then increase power on the other engine until it's at maximum power, again expecting you to apply rudder to prevent yaw.
- I point out to you our current airspeed.
- I pitch the aircraft up, a little at a time, in order to gradually reduce airspeed. After each change in pitch, I wait for you to increase rudder as necessary, and re-trim the rudder, then we look at the new, lower airspeed.
- I repeat this as many times as necessary until you run out of rudder, at which point we note the speed - this is Vmc.
Everything up to this point is a repeat of a previous exercise we've already done, to demonstrate the connection between airspeed and rudder.
- I then pitch up once more, just a tiny bit this time to decrease speed by only a couple of knots. I encourage you to apply more rudder to prevent the yaw, but of course you are unable. Over the next few seconds, the yaw develops into a spiral dive.
- I take control of the rudder ("I have control"), then demonstrate the recovery: close both throttles, lower the nose, then recover to the desired attitude.
Depending on circumstances (student ability, weather, aircraft type, etc), I might repeat this a few times with different scenarios: wings level vs 5 degrees of bank is my favourite, but also critical vs non-critical engine, zero thrust vs windmilling, noting what difference the change makes to Vmc.
FFF
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The following is provided for information only - please get proper instruction, in an aircraft, from a multi-engine instructor, as part of an approved course!
Other instructors may do this slightly differently, but here's how I do it:
- Perform relevant airmanship actions - safe altituden, appropriate area, good lookout.
- I have control of the aircraft; however, you have control of the rudder.
- Please use the rudder to prevent yaw (using a distant visual feature as a reference, as taught on previous exercises).
- Whilst maintaining pitch, and keeping wings level with ailerons, I gradually close one throttle, expecting you to apply rudder (and trim) to prevent yaw. I then increase power on the other engine until it's at maximum power, again expecting you to apply rudder to prevent yaw.
- I point out to you our current airspeed.
- I pitch the aircraft up, a little at a time, in order to gradually reduce airspeed. After each change in pitch, I wait for you to increase rudder as necessary, and re-trim the rudder, then we look at the new, lower airspeed.
- I repeat this as many times as necessary until you run out of rudder, at which point we note the speed - this is Vmc.
Everything up to this point is a repeat of a previous exercise we've already done, to demonstrate the connection between airspeed and rudder.
- I then pitch up once more, just a tiny bit this time to decrease speed by only a couple of knots. I encourage you to apply more rudder to prevent the yaw, but of course you are unable. Over the next few seconds, the yaw develops into a spiral dive.
- I take control of the rudder ("I have control"), then demonstrate the recovery: close both throttles, lower the nose, then recover to the desired attitude.
Depending on circumstances (student ability, weather, aircraft type, etc), I might repeat this a few times with different scenarios: wings level vs 5 degrees of bank is my favourite, but also critical vs non-critical engine, zero thrust vs windmilling, noting what difference the change makes to Vmc.
FFF
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Moderator
Excellent and useful post FFF.
From my place as a non instructor, but tester of such things, I will offer a few additional thoughts to FFF's, though not to contradict....
The Vmca number in the flight manual, which you are aiming for, you may actually find you can better, for two reasons:
If flying a normally aspirated twin at altitude, you started loosing power as you climbed, so you don't have as much asymmetrical power to overcome at altitude. So, you can fly more slowly with the rudder effectiveness you have up there.
The Vmca number is also predicated on a speed at which a sudden loss of power can be managed. You can manage a slower speed, if you creep down to it well prepared.
The weight and C of G of the aircraft may also affect Vmca, though not always as you would expect, so read the flight manual...
From my place as a non instructor, but tester of such things, I will offer a few additional thoughts to FFF's, though not to contradict....
The Vmca number in the flight manual, which you are aiming for, you may actually find you can better, for two reasons:
If flying a normally aspirated twin at altitude, you started loosing power as you climbed, so you don't have as much asymmetrical power to overcome at altitude. So, you can fly more slowly with the rudder effectiveness you have up there.
The Vmca number is also predicated on a speed at which a sudden loss of power can be managed. You can manage a slower speed, if you creep down to it well prepared.
The weight and C of G of the aircraft may also affect Vmca, though not always as you would expect, so read the flight manual...
I must step in here as I have a big problem of FFF's description.
The point of a "VMC" training (and I think the earlier convoluted debate on VMC vs VMCA was pedantry in the lieu of practicality, but that is another debate) is to teach the student to recognize when the aircraft is approaching VMC and to learn how to effectively recover from this dangerous low speed regime.
It is entirely unnecessary and IMO quite dangerous, to actually slow to a speed where full rudder can no longer control the aircrafts direction. For many common light twin trainers this will result in a speed very close to stalling speed.
A much better way to demonstrate VMC is to, after the aircraft is stabilized with one engine zero thrusted, go to full power on the operating engine and then reduce airspeed while maintaining direction. When I feel the student had put in about 1/2 of total rudder travel I tell the student to apply no more rudder but continue decreasing airspeed. As the aircraft starts to yaw and roll into the dead engine I have the student reduce power on the operating engine and lower the nose to accelerate in order to regain control, which teaches both the recognition of VMC loss of control and to have the student practice the recovery procedure.
Incidentally the closes I have ever come to be killed by a student was on a ME training flight in a PA34 Seneca. The exercise was a engine failure on a go around. We climbed to 4000 ft AGL and set up with gear down flaps full and landing red speed. I then told the student to go around and as he shoved the power up I pulled one throttle back. For some inexplicable reason the student then applied full back stick. Before I could react the aircraft stalled and snapped rolled. I tool over control with the aircraft inverted and 40 degrees nose down
. If I had not been an aerobatic instructor I probably would not have survived. I take single engine work at lower airspeeds very seriously....
The point of a "VMC" training (and I think the earlier convoluted debate on VMC vs VMCA was pedantry in the lieu of practicality, but that is another debate) is to teach the student to recognize when the aircraft is approaching VMC and to learn how to effectively recover from this dangerous low speed regime.
It is entirely unnecessary and IMO quite dangerous, to actually slow to a speed where full rudder can no longer control the aircrafts direction. For many common light twin trainers this will result in a speed very close to stalling speed.
A much better way to demonstrate VMC is to, after the aircraft is stabilized with one engine zero thrusted, go to full power on the operating engine and then reduce airspeed while maintaining direction. When I feel the student had put in about 1/2 of total rudder travel I tell the student to apply no more rudder but continue decreasing airspeed. As the aircraft starts to yaw and roll into the dead engine I have the student reduce power on the operating engine and lower the nose to accelerate in order to regain control, which teaches both the recognition of VMC loss of control and to have the student practice the recovery procedure.
Incidentally the closes I have ever come to be killed by a student was on a ME training flight in a PA34 Seneca. The exercise was a engine failure on a go around. We climbed to 4000 ft AGL and set up with gear down flaps full and landing red speed. I then told the student to go around and as he shoved the power up I pulled one throttle back. For some inexplicable reason the student then applied full back stick. Before I could react the aircraft stalled and snapped rolled. I tool over control with the aircraft inverted and 40 degrees nose down
. If I had not been an aerobatic instructor I probably would not have survived. I take single engine work at lower airspeeds very seriously....
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Thank you so much FFF.
Just what I wanted. I had done this exercise with my instructor about 9 months ago, and I had forgotten about it all completely. I thought it would be good idea to know what to expect when I do this again later this month during my ME endorsement test.
Just what I wanted. I had done this exercise with my instructor about 9 months ago, and I had forgotten about it all completely. I thought it would be good idea to know what to expect when I do this again later this month during my ME endorsement test.
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Not sure I agree with you, BPF. There are several training benefits of going right down to actual Vmc which I can think of. Safety is, of course, paramount, and your story of the snap roll is sobering, but - my personal opinion, I have no problem if you don't agree - there is no safety issue demonstrating Vmc when I have control of the elevators, ailerons and throttles.
QED!
(I started typing up the benefits of my method, but then stopped because I feel this conversation really belongs in the Instructors forum rather than Private Flying - it relates solely to instructing technique. If you're interested enough to continue discussing, let's start a new thread in there.)
As for your snap roll, I'll bet you were glad you were at 4000' and not 400'! Makes me wonder how I'd handle that... I haven't done any aeros other than spins for nearly 10 years.
FFF
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Other instructors may do this slightly differently, but here's how I do it:
(I started typing up the benefits of my method, but then stopped because I feel this conversation really belongs in the Instructors forum rather than Private Flying - it relates solely to instructing technique. If you're interested enough to continue discussing, let's start a new thread in there.)
As for your snap roll, I'll bet you were glad you were at 4000' and not 400'! Makes me wonder how I'd handle that... I haven't done any aeros other than spins for nearly 10 years.
FFF
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There are several training benefits of going right down to actual Vmc which I can think of.
I have to agree with Big Pistons Forever. This is the technique I have used sucessfully for many years.
It's a bit like stalling, where we are not teaching students how to stall the aircraft but teach them how to apply the correct recovery technique, loss of control at Vmca is the same.
Not sure I agree with you, BPF. There are several training benefits of going right down to actual Vmc which I can think of. Safety is, of course, paramount, and your story of the snap roll is sobering, but - my personal opinion, I have no problem if you don't agree - there is no safety issue demonstrating Vmc when I have control of the elevators, ailerons and throttles.
In part because it is quite low-powered, the Twin Comanche on a single-engine (and at any altitude at which you would contemplate doing the exercise) retains sufficient rudder authority to maintain directional control right down to the stall. I think there were some nasty accidents in the 60s and 70s involving Vmca "demonstrations" in training situations that resulted stall-spin upsets, and it was as a result that the POH Vmca of the Twin Comanche was raised to the modern 78 KCAS figure, to give the instructors and examiners an excuse to terminate the demonstration after slowing to that speed.
Moderator
It is entirely unnecessary and IMO quite dangerous, to actually slow to a speed where full rudder can no longer control the aircrafts direction. For many common light twin trainers this will result in a speed very close to stalling speed.
In flying at Vmc, not only could you be very close to stalling speed, you could be right there. It is possible, and indeed considered favourable, that a twin reach stalling speed before directional control cannot be maintained with one engine inop.
I'm sure you are aware that the design requirements for these aircraft include: (my bold)
§ 3.123 One-engine-inoperative stalls. Multiengine airplanes shall not display any undue spinning tendency and shall be safely recoverable without applying power to the inoperative engine when stalled with:
(a) The critical engine inoperative,
(b) Flaps and landing gear retracted,
(c) The remaining engines operating at up to 75 percent of maximum continuous power, except that the power need not be greater than that at which the use of maximum control travel just holds the wings laterally level in approaching the stall. The operating engines may be throttled back during the recovery from the stall.
During recent flight testing I was doing in each of two Navajos, I was nervous about entering that phase of flight with the aircraft (both PA-31's, one with wing lockers, the other without). I am not well experienced in Navajos, and suffered from years of hearing hangar talk about how poorly they flew on one engine.
To the contrary, at both forward C of G gross weight, and light aft, I found these two Navajos, both with different external mods, to be very docile in this phase of flight. With the left engine both at idle, and stopped and feathered, and the right at 75% power, stalls were quite controllable.
On some occasions I reached Vmca first, and the stall was performed with either a slight heading change underway, or slightly reduced power on the right. Other times, I reached the stall first.
I have done similar flying in Cessna 300 twins, a King Air 200, and DHC-6, and found them to be similarly agreeable. I have not tried it in the light Piper twins, though the certification requirements would leave me expecting they would be equally compliant.
I agree that mishandling the aircraft can result in unexpected areobatics, and am empathetic to Big Piston's scare. I have found (first from some unsatisfactory experience in my poor briefing) that a very thorough ground briefing as to who will do what, and what that will be, can be a great benifit to a no suprizes flight. I have occasion to be doing this type of flying in aircraft types I have never before flown, and sometimes in the company of other company or safety pilots. I have found that a complete review of the flight test plan [= lesson] (which takes 45 minutes to an hour), and the normal pre takeoff pilot briefing, tailored to the flight, are an excellent way to keep things safe.
In discussing what is to be flown, and what should be, but yet could be expected, everything is out in the open before you leave the ground. For any "newer" pilot reading this, who is in the midst of receiving instruction, do not try to truncate your instructor's ground briefing prior to a lesson. If your instructor requires a half hour of ground briefing, prior to an hour flight, eagerly pay the instructor for that time - particularly if you have questions, or something is new to you. You'll feel very much happier having spent the extra before hand, than having Big Pistons yell "I've got it" as you roll inverted in a Seneca after doing the wrong thing!
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It is important to remember in all single engine asymmetric situations that the one thing that will always get you out of trouble and stabilise things, is to reduce throttle on the good engine.
Have a real engine out scenario and have to make a steep turn into the "dangerous" dead engine to make a field? Reduce throttle. Can't control heading? Reduce throttle. There's nothing that says you're not allowed to do that.
Sometimes in ME training stuff tends to get fixated on "full power on working engine" and it can lead to bad practice at times. I did numerous unstable and semi-scary approaches during my training because I got fixated on this. It's easily done.
Have a real engine out scenario and have to make a steep turn into the "dangerous" dead engine to make a field? Reduce throttle. Can't control heading? Reduce throttle. There's nothing that says you're not allowed to do that.
Sometimes in ME training stuff tends to get fixated on "full power on working engine" and it can lead to bad practice at times. I did numerous unstable and semi-scary approaches during my training because I got fixated on this. It's easily done.
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I dont suppose there would be critical engine on aircraft with centreline thrust arrangement, would there. Apart from P factor effect diminishing from the loss of one engine(assuming both rotating clockwise), and the degraded climb performance. Correct me if I'm wrong.
Can ME with centreline thrust propellers be considered to behave like a single engine in the event of one engine failure and Vmca not being applicable to them?
Can ME with centreline thrust propellers be considered to behave like a single engine in the event of one engine failure and Vmca not being applicable to them?
First off I would like say that I think your posts are always very informative and I value your contributions to this forum. However I think you have entirely
missed the point I was trying to make by making a common mistake, that is extrapolating your very considerable experience to what should be expected of a low hour student.
It is entirely appropriate that an engineering test pilot explore the full VMC regime because the point of the exercise is to assess compliance with the certification standards. However when teaching the Multi Engine rating demonstrating the actual VMC in certification required configuration is irrelevant. The point of the exercise is teach the student to recognize the onset of a speed below which the aircraft can be directionally controlled and then how to safely recover. This can be just as easily and IMO much more safely, be demonstrated by limiting rudder travel to half travel during the demonstration. I would also like to point out that the flight in which I experienced the upset in the Seneca was preceded, like all my ME instructional flights, with a comprehensive brief which emphasized the importance of lowering the nose to maintain a safe airspeed during an engine failure in an overshoot. Despite that the student in the heat of the moment got everything backwards.....but then that is the challenge of teaching low houred PPL's in complex airplanes, a challenge that does not exist for test pilots flying a very carefully thought out test card.
FFF
I respect what you say but I guess we have a philosophical difference over the conduct of flight training. Your having control of the rudder, elevator and power during a full on VMC makes the manoever safe, but for the manoever to IMO be of full value the student on their own must be able to demonstrate they can control the aircraft. They can obviously only do this if they have their hands on the rudder, elevator, and throttle.....
I guess I have contributed to a conversation that most properly belongs in the instructor forum so my apologies for the thread drift
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Can ME with centreline thrust propellers be considered to behave like a single engine in the event of one engine failure and Vmca not being applicable to them?
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what should be expected of a low hour student.
That said, we would all agree that low speed, and particularly asymmetric maneuvers, are the mosy risky. I find that there is a grey zone where we as pilots of more experience are morally bound to not encourage low hour pilots to go "exploring" these risks, but on the other hand, we bear some responsibilty for assuring that these low hour pilots are aware that the aircraft has been designed to behave well in these situations - to a point.
Right or wrong, (and I could be either) I think that new pilots can benefit from experiencing flight a bit beyond "the point", in a artificially safe environment. Hopefully it will be memorable for them in a way which will aid them in getting the most out of the plane when they need to, without creating unsafe situations, or being tempted to "fool around" later.
(And I realize I further thread drift here, pardon me!)
I consider Vmca training to have similarity to spin training in this respect. As I am certain that a low hour pilot should experience a one turn spin during training, I also feel that pilot (during ME training) should experience flight with only one engine developing power, where directional control can no longer be maintianed - just to see what it's like.
Without wanting to offend any instructor, I would state that if training of this type is not being done, because it is thought to be "too dangerous", that sends the wrong message to newer pilots. These maneuvers can be very dangerous, if flown in the wrong circumstances. But if planned, and executed carefully, should have a margin of safety which is acceptable. If that margin of safety is not acceptable because the instructor themself cannot safely recover the possible departure from controlled flight which could result, that's a whole different problem, which, in my opinion, should not be a reason to not demonstrate. I certainly agree that a snap roll in a Seneca is a really bad occurance, but I know that the aircraft should be able to withstand it safely, if the recovery is reasonable. (apparently it can, thanks for the good flying Big Pistons!). I worry that there are instructors avoiding flying anywhere near the stall, because they could not recover such an unusual attitude. I opine that they should be able to, if they are to be instructing on type.
(I drift further, pardon me...)
During a design complince flight test in a club 172, accompanied by an instructor with rank in the club, to "check me out", he asked me to demonstrate a roll. I declined. He pressed a bit, asking, "this plane would roll wouldn't it?". Yes, but I'm not going to do it. I honestly thought it was a trap, to get me to do something stupid. From that expression of loss on his face, I realized that he really did want to experience a roll. Sad for him that he never had. It was not the time/place/airplane on that flight - his loss.
In some of the things I post here, I seek to add my one small voice to those who would say that our industry should not be diluting flight training, particularly because the training of the instructors themselves is being diluted over time. During my low hours training, I was taught spins, 'till I could do them well, I was taught flight with one engine actually feathered in the 310, until I could no longer maintain directional control, and I was taught to loop and roll. I practice these skills as often as the aircraft type permits. I hope the students of this era realize their responsibility in obtaining this type of training from compotent instructors, and gently, yet firmly, assert their right to those learning experiences.
Though the organisation and regulator can set the training curriculum and learnign goals, the student and new pilot play a role in asking for "more", and indicating that that training not being available is not good enough. That said, you lower time pilots..... You bear the responsibility for obtaining that training, taking it seriously, and having the good discipline to not fool around later!
Pilot DAR
First off I think it is important to point out that while my principal flying job is flying an airtanker in aerial forest fire suppression operations I also hold a current Transport Canada Class 1 aeroplane flight Instructor rating and a Class 1 aerobatic instructor rating, so I can situate the theory into the practice when it comes to discussing instruction practices
I am also discouraged by the "dumbing down" of flight instructor ratings. This is IMO particularly egregious with multi engine training which is unfortunately taught by instructors which have little or no actual twin flying experience.
I think all flying instruction should be conducted with a consideration of risk and rewards vs the training objectives. An example of this would e your spin example. Obviously you can not demonstrate a spin without actually stalling the aircraft with enough yaw to allow the aircraft to depart and enter auto rotation. In the case of a VMC demo however the effect of VMC and the procedure to recover from a VMC induced loss of directional control can IMO be just as convincing be demonstrated by limiting rudder travel such that
the MC induced ya occurs at a higher safer speed. Therefore my personal risk reward calculus is that there is no benefit to talking the speed down to actual
VMC.
In any case the problem with VMC is not recovering from a preplanned and briefed VMC demo at altitude, a situation that is unlikely to actually occur in the real world, it is to deal with the low altitude and low speed regime in the case of an EFATO. There is a horrible record of low altitude fatal loss of control accidents after engine failures in light twins.
The current multi engine training syllabus is IMO not doing a very good job of preparing new twin pilots because it is simply too dangerous to do actual low altitude simulated engine failures. The good news is the emerging new generation of flight sims like the Redbird and the alsim now have realistic enough visual systems and flight modelling to allow students to practice the worst case scenarios. I strongly encourage all the light twin student pilots I know to invest in a few hours of training in one of these sims even though the tie can not be counted. It is also vital IMO that anyone flying a light twin take annual recurrent training. If they don't then I think the second engine will only be good for taking them to the scene of the accident......
First off I think it is important to point out that while my principal flying job is flying an airtanker in aerial forest fire suppression operations I also hold a current Transport Canada Class 1 aeroplane flight Instructor rating and a Class 1 aerobatic instructor rating, so I can situate the theory into the practice when it comes to discussing instruction practices
I am also discouraged by the "dumbing down" of flight instructor ratings. This is IMO particularly egregious with multi engine training which is unfortunately taught by instructors which have little or no actual twin flying experience.
I think all flying instruction should be conducted with a consideration of risk and rewards vs the training objectives. An example of this would e your spin example. Obviously you can not demonstrate a spin without actually stalling the aircraft with enough yaw to allow the aircraft to depart and enter auto rotation. In the case of a VMC demo however the effect of VMC and the procedure to recover from a VMC induced loss of directional control can IMO be just as convincing be demonstrated by limiting rudder travel such that
the MC induced ya occurs at a higher safer speed. Therefore my personal risk reward calculus is that there is no benefit to talking the speed down to actual
VMC.
In any case the problem with VMC is not recovering from a preplanned and briefed VMC demo at altitude, a situation that is unlikely to actually occur in the real world, it is to deal with the low altitude and low speed regime in the case of an EFATO. There is a horrible record of low altitude fatal loss of control accidents after engine failures in light twins.
The current multi engine training syllabus is IMO not doing a very good job of preparing new twin pilots because it is simply too dangerous to do actual low altitude simulated engine failures. The good news is the emerging new generation of flight sims like the Redbird and the alsim now have realistic enough visual systems and flight modelling to allow students to practice the worst case scenarios. I strongly encourage all the light twin student pilots I know to invest in a few hours of training in one of these sims even though the tie can not be counted. It is also vital IMO that anyone flying a light twin take annual recurrent training. If they don't then I think the second engine will only be good for taking them to the scene of the accident......
Moderator
Pistons,
I will certainly defer to your qualification as an instructor, and recognize that there are probably valid training techinqes with which I am simply unfamiliar. As long as the recipient of the training is getting either real, or very realistic training, the core aspects have been met.
I have not flown a simulator in 15 years, so they probably have improved a lot since my ATC 810 days. I did fly Flight Safety's Twin Otter sim quite a bit, and found it extremely worthwhile. I was recently told by a very experienced Twin Otter pilot, that he felt it did not represent Vmca in a Twin Otter.
That, however is moot here, as I'm sure that simulator is not readily available to light twin pilots!
I wonder if today's basic simulators have representative control force feedback, so the pilots learns what it feels like. I have no idea though, so I shall leave the sim discussion with those qualified...
Please excuse the continued thread drift!
I will certainly defer to your qualification as an instructor, and recognize that there are probably valid training techinqes with which I am simply unfamiliar. As long as the recipient of the training is getting either real, or very realistic training, the core aspects have been met.
I have not flown a simulator in 15 years, so they probably have improved a lot since my ATC 810 days. I did fly Flight Safety's Twin Otter sim quite a bit, and found it extremely worthwhile. I was recently told by a very experienced Twin Otter pilot, that he felt it did not represent Vmca in a Twin Otter.
That, however is moot here, as I'm sure that simulator is not readily available to light twin pilots!
I wonder if today's basic simulators have representative control force feedback, so the pilots learns what it feels like. I have no idea though, so I shall leave the sim discussion with those qualified...
Please excuse the continued thread drift!
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The thing to do is practice all this with a competent instructor. When I did my ME CPL, the FI failed the engine and then made me do 45° banked turns in both directions - into the failed engine and away from it. It was a useful exercise.
Addition of a vortex kit to some aeroplanes reduce the Vmc to below the stall at any sort of altitude so you'll stall first before you reach Vmc. The dangerous area is where Vmc and Stall coincide so that they occur at exactly the same moment.
Addition of a vortex kit to some aeroplanes reduce the Vmc to below the stall at any sort of altitude so you'll stall first before you reach Vmc. The dangerous area is where Vmc and Stall coincide so that they occur at exactly the same moment.