747 - Outboard engine failure- why no bank?
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VmcA-2 for 747-400... ¿?¿?¿?
Note for you, ACMS...
xxx
There is NO such thing as a VmcG-2... just a VmcG for 1 engine.
Since you cannot find the VmcA-2 info in your 744 publications...
Would suggest you look at the numbers I gave for the 200/300.
I would say, being conservative, VmcA-2 is close to 165.
Might save you neck one day.
I do engine-out ferries, reason I know the figure for the Classic.
Read the engine-out ferry procedures. Quite an education.
Happy contrails
xxx
There is NO such thing as a VmcG-2... just a VmcG for 1 engine.
Since you cannot find the VmcA-2 info in your 744 publications...
Would suggest you look at the numbers I gave for the 200/300.
I would say, being conservative, VmcA-2 is close to 165.
Might save you neck one day.
I do engine-out ferries, reason I know the figure for the Classic.
Read the engine-out ferry procedures. Quite an education.
Happy contrails
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VMCA2 not quoted for the -400 in any Boeing manuals that I have, seem to remember a figure of 157kts for the -200(R-R) and 162 for the -400 from a conversion course instructor some years ago (but nothing in print!).
VMCG for the -400(P&W), using TO1 at sea level is 116kts.
Aileron into the live engines would probably be required during a 2-engines go-around. (Not recommended by Boeing after gear down, but achievable provided not attempted too late on in approach).
VMCG for the -400(P&W), using TO1 at sea level is 116kts.
Aileron into the live engines would probably be required during a 2-engines go-around. (Not recommended by Boeing after gear down, but achievable provided not attempted too late on in approach).
ACMS - did you never fly 2-eng approaches and landings in the sim during your 744 time?
I have flown the B707, B747-200 and A340 and they ALL require you to maintain an approach speed above VMCA2 until a commit point and thereafter a speed reduction to Vref.
We used to do 2-eng base flying on the aircraft. For the B707 the go around procedure from 300` was to continue down the glideslope whilst accelerating with full power on the inner and as much power as could be obtained without losing directional control on the outer until enough speed was achieved to have full power on both - only then was a climb away started. The lack of rudder authority with too much thrust on the outer was very obvious.
I have flown the B707, B747-200 and A340 and they ALL require you to maintain an approach speed above VMCA2 until a commit point and thereafter a speed reduction to Vref.
We used to do 2-eng base flying on the aircraft. For the B707 the go around procedure from 300` was to continue down the glideslope whilst accelerating with full power on the inner and as much power as could be obtained without losing directional control on the outer until enough speed was achieved to have full power on both - only then was a climb away started. The lack of rudder authority with too much thrust on the outer was very obvious.
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Note on VmcA - VmcG speeds
Just be aware that the differences in number between the numbers you gentlemen mention are all based on different engines...
There is a tremendous amount of difference (and effect on 747 yaw to be counteracted with the rudder) between a JT9D-7 and a JT9D-7R4G2. Same story between CF6-45A and CF6-80EC2 or RB211-524B and a RB211-524G...
xxx
On the engines cited above, the thrust varies between 46,000 lbs and 58,000 lbs. I have seen minimum V1 speeds (VmcG) varying between 114 and 130 KIAS depending on type of engine (thrust). There is NO "standard" number which can be memorized. And again, if not sure, being conservative, I add or substract "1 or 2 knots" when necessary.
xxx
Happy contrails
There is a tremendous amount of difference (and effect on 747 yaw to be counteracted with the rudder) between a JT9D-7 and a JT9D-7R4G2. Same story between CF6-45A and CF6-80EC2 or RB211-524B and a RB211-524G...
xxx
On the engines cited above, the thrust varies between 46,000 lbs and 58,000 lbs. I have seen minimum V1 speeds (VmcG) varying between 114 and 130 KIAS depending on type of engine (thrust). There is NO "standard" number which can be memorized. And again, if not sure, being conservative, I add or substract "1 or 2 knots" when necessary.
xxx
Happy contrails
Yes we did double Eng failures after T/O at high weights, was interesting.
And we did 2 Eng approaches, if I remember correctly you didn't put the gear down UNTIL you were 100% certain of landing. You were then committed, however in the sim we used to practice go-arounds after gear down. You accelerated down the slope while cleaning up to flap 5 I think? then climbed away. it's been a while since my conversion to the 400 ( 14 years ago )
We all know VMCG and VMCA with 2 engs out is higher.
Our T/O data is all computer done now and it only gives you the VMCG.
Interesting though, it must be in the Boeing AFM which we can't see?
Thanks for the info but as I'm now on the 777, VMCA after 2 Engines fail would be the last thing on my mind!!
And we did 2 Eng approaches, if I remember correctly you didn't put the gear down UNTIL you were 100% certain of landing. You were then committed, however in the sim we used to practice go-arounds after gear down. You accelerated down the slope while cleaning up to flap 5 I think? then climbed away. it's been a while since my conversion to the 400 ( 14 years ago )
We all know VMCG and VMCA with 2 engs out is higher.
Our T/O data is all computer done now and it only gives you the VMCG.
Interesting though, it must be in the Boeing AFM which we can't see?
Thanks for the info but as I'm now on the 777, VMCA after 2 Engines fail would be the last thing on my mind!!
Last edited by ACMS; 25th Sep 2008 at 01:03.
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To go back to the original question, an FAA wonk told me years ago that for the vast majority of multiengine aircraft, the ideal bank with one out was two and a half degrees. The five degrees is a number for certification. Because of people like me, most training is done with no bank, since that is better then five or more degrees. I had a an instructor on the whale tell me that it holds true there. Unfortunately, I can point to nothing in writing.
