engine fail B777 after V1, TAC on
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engine fail B777 after V1, TAC on
It's a CAE B777-333ER simulator. Instructor says there will be less rocking of the wings if feet are placed flat in the floor after rotation. He says I was "fighting" the TAC. Hold heading with aileron he said ; TAC trims rudder for min drag.
I'd appreciate opinions to this recommendation.
How is the technique different if TAC is off ? ( I'm guessing conventional technique : keep straight with rudder, trim rudder as required, i.e, you cannot put feet flat in the floor ?
I'd appreciate opinions to this recommendation.
How is the technique different if TAC is off ? ( I'm guessing conventional technique : keep straight with rudder, trim rudder as required, i.e, you cannot put feet flat in the floor ?
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TAC on = Our manual states that TAC doesn't not FULLY compensate for yaw. So some rudder use is preferred. Can it be done with your feet on the floor? Usually yes. In general you just set a significantly smaller than usual rudder deflection and hold it. Do not waggle your feet.
TAC off = standard engine out rudder technique
TAC off = standard engine out rudder technique
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The instructor is a dangerous criminal if he tells you to take your feet off the rudders during rotation. He should be grounded and retrained himself. Quickly!
The TAC, just as anything else, can and will fail when least expected.
For instance in an engine seizure or separation the TAC loses engine input and will not react. You have to adjust rudder yourself.
Please inform the instructor's senior about this. I hope CAE will react appropriately.
The TAC, just as anything else, can and will fail when least expected.
For instance in an engine seizure or separation the TAC loses engine input and will not react. You have to adjust rudder yourself.
Please inform the instructor's senior about this. I hope CAE will react appropriately.
My twopence worth is that having flown 10000 hrs plus on a heavy "non TAC'd" Boeing I also found myself fighting the TAC when I transitioned to the 777.
On the previous type the teaching was to apply rudder A/R and then lock the feet/apply constant foot pressure..if you felt the foot loads changing you'd stuffed up.
OTOH with TAC you certainly still need to be ready to apply appropriate rudder as the engine fails but you then need to be ready for TAC to start reducing your foot loads. Another way of thinking of it (IMHO) is that you need to be ready to relax the feet as the TAC catches up with what you've done...maybe that's what the instructor is getting at?
On the previous type the teaching was to apply rudder A/R and then lock the feet/apply constant foot pressure..if you felt the foot loads changing you'd stuffed up.
OTOH with TAC you certainly still need to be ready to apply appropriate rudder as the engine fails but you then need to be ready for TAC to start reducing your foot loads. Another way of thinking of it (IMHO) is that you need to be ready to relax the feet as the TAC catches up with what you've done...maybe that's what the instructor is getting at?
Last edited by wiggy; 23rd Feb 2012 at 20:22.
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777 rudder trim TAC fail
Forgive me for latching on to your thread but I’m soon to be starting my 777 course. I’ve been reading about TAC fail with an efato.
This may be obvious but there’s no mention of which way you trim the rudder - is it towards the failed or live (dead-leg) engine.
This may be obvious but there’s no mention of which way you trim the rudder - is it towards the failed or live (dead-leg) engine.
That said I can only reiterate what was said both upthread and elsewhere - regardless of whether TAC is working or not if an engine fails you'll still need to use your feet to some degree and you'll need to trim to some degree. Now TBH I'm a bear with a small brain so I didn't think in terms of I needed to trim "left" or "right", I just tried to remove the leg load.....just as you've probably done on your previous multi-engine types.
If all else fails you'll no doubt do at least one sim before encountering EFATOS and TAC, so you should have an opportunity to play with the rudder trim before it becomes to the course.
We used to practice engine failures with and without TAC separately. Then someone pointed out that this probably wasn’t the best kind of training, so we just do engine failures now without any pre-expectation, which is much closer to real life (TAC working or not for real is about 50/50 after 25+ years' worth of EFs).
As Wiggy says, I’m sure you’ll have plenty of time to work it all out. For me, the trick is not to try and get it too precise, and definitely not to look down and back for the trim indicator when not far off the ground...!
As Wiggy says, I’m sure you’ll have plenty of time to work it all out. For me, the trick is not to try and get it too precise, and definitely not to look down and back for the trim indicator when not far off the ground...!
Curious concept
How the pilot in the loop needs to respond to an engine failure is a simple tracking problem, it should not need cognition, it is push n pull to retain an eye pleasing outcome. On the takeoff, the driver is driving his eyeballs towards a few fixed point at the end of the runway. An engine failure disturbs the vector of the aircraft and gives an error in the tracking task, that the driver responds to, on the ground, that be rudder to return the eyeballs to the desired point in space.
TAC ON or OFF merely reduces the force necessary to be applied, once the pilot has applied an initial input. It works quite well, but after 9000 hours using it, whether it works r not is irrelevant. The pilot response remains the same in the 777 or 787 as it would be in a Pitts in an wind, or a Baron running along the tarmac with varying thrust strings on each engine.
TAC was a nice change to the B767 and 757 and to the 737, where it is nice to have a hand on the rudder trim when flying about the patterns with one blender silent.
For the FNG to the type, ask your IP to run you down the runway and for the IP to vary randomly the thrust levers arbitrarily while the FNG tracks a centreline, or the point at the end of the runway. Same deal airborne sorts out asymmetric flight fairly promptly.
Funny though, having a major thrust loss in the 773 is enough to toss the APLT off, so don't assume that these engines don't bark n bite.
TAC ON or OFF merely reduces the force necessary to be applied, once the pilot has applied an initial input. It works quite well, but after 9000 hours using it, whether it works r not is irrelevant. The pilot response remains the same in the 777 or 787 as it would be in a Pitts in an wind, or a Baron running along the tarmac with varying thrust strings on each engine.
TAC was a nice change to the B767 and 757 and to the 737, where it is nice to have a hand on the rudder trim when flying about the patterns with one blender silent.
For the FNG to the type, ask your IP to run you down the runway and for the IP to vary randomly the thrust levers arbitrarily while the FNG tracks a centreline, or the point at the end of the runway. Same deal airborne sorts out asymmetric flight fairly promptly.
Funny though, having a major thrust loss in the 773 is enough to toss the APLT off, so don't assume that these engines don't bark n bite.
