Engine Failure on Takeoff actions
Thread Starter
Join Date: Aug 2003
Location: Surrey
Posts: 1,217
Likes: 0
Received 0 Likes
on
0 Posts
Engine Failure on Takeoff actions
In the rough running thread there was a small diversion on the specific immediate actions on an EFATO.
here are some points from an article in AOPA USA, the key point being the imperative of 'unloading the wings' and here is a view that if it was trimmed to fly before the failure, it will fly (descending rather than climbing obviously) after the failure with no need for the pilot to man handle the aircraft into the glide attitude.
I was in the former camp as it seemed logical, but decided to give it a go.
At a safe height I set up in a trimmed climb at Vy + 10 (my typical climb away speed) and pulled the power to idle with the only control input being gentle roll control to keep up right, and Low and Behold if it didn't arc right over into a descent. It over shot the target airspeed initially and then bobbled around the target airspeed but I didn't go more than a couple of knots below the trimmed airspeed. So if you climb away trimmed, then as long as you don't pull (at least in my airplane) it will just naturally move to a glide at pretty close to best glide.
It IS however a pretty dramatic view change from mostly sky to a lot of ground. Interestingly I can remember lots of stall practice (approach, accelerated, departure), lots of PFLs and some 'What would you do if questions' but never configuring for a departure climb and then going to idle power to see that particular transition. What about other people's training?
here are some points from an article in AOPA USA, the key point being the imperative of 'unloading the wings' and here is a view that if it was trimmed to fly before the failure, it will fly (descending rather than climbing obviously) after the failure with no need for the pilot to man handle the aircraft into the glide attitude.
I was in the former camp as it seemed logical, but decided to give it a go.
At a safe height I set up in a trimmed climb at Vy + 10 (my typical climb away speed) and pulled the power to idle with the only control input being gentle roll control to keep up right, and Low and Behold if it didn't arc right over into a descent. It over shot the target airspeed initially and then bobbled around the target airspeed but I didn't go more than a couple of knots below the trimmed airspeed. So if you climb away trimmed, then as long as you don't pull (at least in my airplane) it will just naturally move to a glide at pretty close to best glide.
It IS however a pretty dramatic view change from mostly sky to a lot of ground. Interestingly I can remember lots of stall practice (approach, accelerated, departure), lots of PFLs and some 'What would you do if questions' but never configuring for a departure climb and then going to idle power to see that particular transition. What about other people's training?
Join Date: Jun 2003
Location: EuroGA.org
Posts: 13,787
Likes: 0
Received 0 Likes
on
0 Posts
An interesting Q might be whether to select landing flap. It knocks quite a bit off the stall speed in some types - best part of 10kt in mine I think. That's a lot less energy to get rid of when one reaches the ground.
Why do it if it's not fun?
Join Date: Jul 2001
Location: Bournemouth
Posts: 4,779
Likes: 0
Received 0 Likes
on
0 Posts
Mm,
I agree that what you've found is exactly what will happen.
But I'm not sure I'd teach a pilot to do it that way. And there are two reasons.
When flying, in trim and hands off, a pilot will naturally tend to make corrections in order to maintain the desired attitude. When an EFATO occurs, there is a very distinct change in attitude, as you discovered. If a pilot is taught to "leave everything alone", there would be a natural tendency to leave everything alone, including the attitude. Only be conciously appreciating that there is a large attitude change, and positively effecting that attitude change, can you be sure that human factors don't conspire to override the natural tendency of the aircraft to pitch down, and the result will not be nice.
The second reason is a little more practical. Go and repeat your experiment, but this time, use a stopwatch to measure the time it takes to settle down in a steady descent. Now repeat the exercise, but instead of letting the aircraft take care of itself, positively select the gliding attitude, and time it again. You will find that it all happens much quicker if you do something positive, which a) means you get to your glide speed quicker, so glide further, and b) means you can set your attitude then move onto something else much quicker. Attitude+Power=Performance - can't do much about the power, but set the attitude and you'll get the performance you want!
Having said that, I wouldn't dismiss your experiment completely. One thing it does show is that little, if any, trim change is needed (in your aircraft, at any rate) to go from a climb to a glide. That will be the case whether you let the aircraft settle into the descent itself, or positively set the attitude. It might not be the case in other types, so it's worth everyone experimenting (at a safe height) so that they know what way to expect to move the trim wheel if they have an EFATO.
FFF
-------------
I agree that what you've found is exactly what will happen.
But I'm not sure I'd teach a pilot to do it that way. And there are two reasons.
When flying, in trim and hands off, a pilot will naturally tend to make corrections in order to maintain the desired attitude. When an EFATO occurs, there is a very distinct change in attitude, as you discovered. If a pilot is taught to "leave everything alone", there would be a natural tendency to leave everything alone, including the attitude. Only be conciously appreciating that there is a large attitude change, and positively effecting that attitude change, can you be sure that human factors don't conspire to override the natural tendency of the aircraft to pitch down, and the result will not be nice.
The second reason is a little more practical. Go and repeat your experiment, but this time, use a stopwatch to measure the time it takes to settle down in a steady descent. Now repeat the exercise, but instead of letting the aircraft take care of itself, positively select the gliding attitude, and time it again. You will find that it all happens much quicker if you do something positive, which a) means you get to your glide speed quicker, so glide further, and b) means you can set your attitude then move onto something else much quicker. Attitude+Power=Performance - can't do much about the power, but set the attitude and you'll get the performance you want!
Having said that, I wouldn't dismiss your experiment completely. One thing it does show is that little, if any, trim change is needed (in your aircraft, at any rate) to go from a climb to a glide. That will be the case whether you let the aircraft settle into the descent itself, or positively set the attitude. It might not be the case in other types, so it's worth everyone experimenting (at a safe height) so that they know what way to expect to move the trim wheel if they have an EFATO.
FFF
-------------
Join Date: Mar 2006
Location: heathrow
Posts: 990
Likes: 0
Received 0 Likes
on
0 Posts
If a pilot is taught to "leave everything alone", there would be a natural tendency to leave everything alone
Join Date: Oct 2007
Location: england
Posts: 98
Likes: 0
Received 0 Likes
on
0 Posts
FFF is right; in the event of an EFATO the crucial element is time or the lack thereof.
What mm's experiment showed was that when an aeroplane is trimmed it is not trimmed for a speed, whatever the pilot may think he is doing, but for an angle.
What mm's experiment showed was that when an aeroplane is trimmed it is not trimmed for a speed, whatever the pilot may think he is doing, but for an angle.
Join Date: Nov 2001
Location: 1000ft above you, giving you the bird!
Posts: 579
Received 0 Likes
on
0 Posts
Having first hand experience of a catastrophic failure after take off at 300ft with a glider attached to the back and a sewage farm in front of me - i can assure you that an aircraft trimmed for glide approach is welcome relief, especially when you start to lose visibility with hot oil smearing the screen, luckily for me and the glider it all turned out fine - however we did turn back -and to qualify that statement i mean, we were departing on a northerly runway and were just passed the airfield boundary when it went bang very loudly, there was a SW runway 100 degrees to our left.
Ditched the glider in a nano second whilst pushing and rolling left to remain in the airfield boundary - made the runway, rolled to a stop slid the canopy back, put my hands up on the canopy frame to assist getting out directly above my brow, immediatley slipped stright back in the seat cos of the oil - crash truck arrives - lift myself out - jump out - open the cowling and look at a conrod poking out of the crank looking at me.....
Guess the type????
Ditched the glider in a nano second whilst pushing and rolling left to remain in the airfield boundary - made the runway, rolled to a stop slid the canopy back, put my hands up on the canopy frame to assist getting out directly above my brow, immediatley slipped stright back in the seat cos of the oil - crash truck arrives - lift myself out - jump out - open the cowling and look at a conrod poking out of the crank looking at me.....
Guess the type????
Join Date: Oct 2005
Location: USA
Posts: 3,218
Likes: 0
Received 0 Likes
on
0 Posts
What mm's experiment showed was that when an aeroplane is trimmed it is not trimmed for a speed, whatever the pilot may think he is doing, but for an angle.
Large pitch changes or airspeed changes aren't necessary when an engine failure occurs. Fly the airplane back down.
In most light airplanes, your climb speed is very close to your best glide speed and if the airplane is trimmed for takeoff, it's properly trimmed to come back down. A power loss is not the end of the world; it's a transition from a climb to a descent, and from power on to a glde. Nothing more.
Thread Starter
Join Date: Aug 2003
Location: Surrey
Posts: 1,217
Likes: 0
Received 0 Likes
on
0 Posts
The pitch change felt 'large' and fast, although there was no need for me to do anything to make the pitch change happen. In real life I would have needed to 'catch it' to keep from accelerating over best glide as it hunted back to its trimmed airspeed in the descent. I pulled the power off over about two seconds and was pitched down to best glide at about 4 seconds - with no material decay in airspeed, which did surprise me. Always worth giving it a try to see if the articles people write are correct or not.
Join Date: Mar 2005
Location: UK
Posts: 551
Likes: 0
Received 0 Likes
on
0 Posts
For many light A/C the speed for Vy is often very close to the speed for best glide. Obviously, when an EFATO occurs, you want to have as much time as possible on your hands. Failure to pitch over without delay, may result in an increase or decrease in airspeed. Deviation from best glide speed will cause you to squander height and therefore time. In my opinion, the first action should be to pitch over without delay and adopt the glide. Finding the A/C in trim, is an added bonus! 
Join Date: Oct 2005
Location: USA
Posts: 3,218
Likes: 0
Received 0 Likes
on
0 Posts
Deviation from best glide speed will cause you to squander height and therefore time.
Don't make the equation harder than it need be. You do not need to agressively push the nose over. You DO need to fly the airplane.
