Flap retraction
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Yep it's in the AFM, remember 400 feet is a minimum not a maximum. We do it or have done it for....
B707/737/747-100/200/300/400/ b757, B777
Airbus 300,320,330,340
MD90,11
Embraer 170
Gulfstream 3/4
Falcon 900/7X
All manufacturer approved and is a default in their software.
this is also the way that crew are trained in Flight Safety
Mutt
B707/737/747-100/200/300/400/ b757, B777
Airbus 300,320,330,340
MD90,11
Embraer 170
Gulfstream 3/4
Falcon 900/7X
All manufacturer approved and is a default in their software.
this is also the way that crew are trained in Flight Safety Mutt
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exactly as per the AFM. On my aircraft the AFM says at V2+20. Height is not a condition for flap retraction. It doesnt matter if you are all engines operating or one engine inop. Its exactly the same. Retract the flaps at V2+20. If you can't accelerate to V2+20 in the climb (perhaps because a powerplant has failed) then use a pre-arranged level acceleration platform to pitch to level flight and accelerate there to V2+20 then retract the flap to get rid of the drag and accelerate further to Venr.
Who was throwing Occams razor at me earlier? Surely the method above is simpler that all that other fannying around because its exactly the same regardless of whether you lose an engine or not. Take off, call of "positive rate" - put the gear up and pitch to 15 degrees, accelerate to V2+20, call of "V2+20" - put the flaps up. If you have lost thrust and cant accelerate to V2+20 in the climb, use the Acceleration Altitude agreed prior (1500 feet) and speed up there.
as that bleeding meerkat says, simples!
Who was throwing Occams razor at me earlier? Surely the method above is simpler that all that other fannying around because its exactly the same regardless of whether you lose an engine or not. Take off, call of "positive rate" - put the gear up and pitch to 15 degrees, accelerate to V2+20, call of "V2+20" - put the flaps up. If you have lost thrust and cant accelerate to V2+20 in the climb, use the Acceleration Altitude agreed prior (1500 feet) and speed up there.
as that bleeding meerkat says, simples!
Okay, have to agree that for all donkeys working i agree that the Flap Retraction Altitude is a hang back to some unknown reason that we all do without really questioning it, and that 400ft agl is most likely chosen because it coincides with the OEI acceleration altitude to get to V2+10 and clean up etc., etc. - i know it's not correct, but what sort of time (seconds) does it take on average i wonder to get from V1 to V2+10 etc., etc when compared to reaching 400ft agl?? probably about the same in my CJ ??
Last edited by First.officer; 20th Nov 2012 at 01:39.
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exactly as per the AFM. On my aircraft the AFM says at V2+20. Height is not "a condition for flap retraction. It doesnt matter if you are all engines operating or one engine inop. Its exactly the same. Retract the flaps at V2+20. If you can't accelerate to V2+20 in the climb (perhaps because a powerplant has failed) then use a pre-arranged level acceleration platform to pitch to level flight and accelerate there to V2+20 then retract the flap to get rid of the drag and accelerate further to Venr.
Who was throwing Occams razor at me earlier? Surely the method above is simpler that all that other fannying around because its exactly the same regardless of whether you lose an engine or not. Take off, call of "positive rate" - put the gear up and pitch to 15 degrees, accelerate to V2+20, call of "V2+20" - put the flaps up. If you have lost thrust and cant accelerate to V2+20 in the climb, use the Acceleration Altitude agreed prior (1500 feet) and speed up there.
as that bleeding meerkat says, simples!"
With that in mind, what if you pass V2 +20 while your gear is in transit, ie the lights have not gone out, do you still select flaps up?
Who was throwing Occams razor at me earlier? Surely the method above is simpler that all that other fannying around because its exactly the same regardless of whether you lose an engine or not. Take off, call of "positive rate" - put the gear up and pitch to 15 degrees, accelerate to V2+20, call of "V2+20" - put the flaps up. If you have lost thrust and cant accelerate to V2+20 in the climb, use the Acceleration Altitude agreed prior (1500 feet) and speed up there.
as that bleeding meerkat says, simples!"
With that in mind, what if you pass V2 +20 while your gear is in transit, ie the lights have not gone out, do you still select flaps up?
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I think the root of the problem is that you are confusing a minimum with an instruction. V2+x (depending on type) is the minimum safe speed for flap retraction, in the same way as Vfe is the maximum for extension. Do you always extend flaps at Vfe as you slow down?
Good luck with a meeting with FSI; unfortunately a large part of the problem is that they don't understand it either so you will not get an authoritative answer even if they sound definitive.
Bear in mind that the checklists are written as a follow up to you having done everything, so by the time you get to reading a checklist which may or may not mention a height or a speed you will be long past it.
That also opens the can of worms of why are they still teaching read and do checklists decades after manufacturers changed to scan flows and challenge and response?
May be able to add some more definitive references later, but I need to go and earn a crust now!
Good luck with a meeting with FSI; unfortunately a large part of the problem is that they don't understand it either so you will not get an authoritative answer even if they sound definitive.
Bear in mind that the checklists are written as a follow up to you having done everything, so by the time you get to reading a checklist which may or may not mention a height or a speed you will be long past it.
That also opens the can of worms of why are they still teaching read and do checklists decades after manufacturers changed to scan flows and challenge and response?
May be able to add some more definitive references later, but I need to go and earn a crust now!
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Originally Posted by BizJetJock
I think the root of the problem is that you are confusing a minimum with an instruction. V2+x (depending on type) is the minimum safe speed for flap retraction...
He is saying that failure to comply in a timely manner degrades flight-path performance, burns fuel and increases noise footprint.
He is not advocating going against anything written in the AFM.
(Incidentally since we are all professionals here and since we have all known since PPL days that the AFM is the word of God herself, can we stop the straw-man arguments about "test-pilot" flying? Even the gashest cowboys I have ever shared a Cessna with know not to argue with the AFM. )
He is claiming - suggesting even in his Tom-like manner - that the height restriction is arbitrary, unnecessary, wasteful, and possibly came out of the mists of time as tribal-knowledge and has no place in modern ops.
It's a point of view that no one has properly knocked down though some have made balanced well-reasoned and informed arguments against.
Not much like a real PPrune thread then.
This should be locked.
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OK, I'll go with the Challenger 605 since it is one of the types I am current on, and the other - the CJ - is not a Part 25 aircraft so really doesn't qualify for this discussion.
So let's start with the AFM.
All it says in the normal procedures section is the After Takeoff Checklist where it just says:
O. After Take-Off Check
(1) LDG GEAR lever .............UP
(2) FLAPS ................. Set to 0°
(3)
No mention of heights or speeds.
In the FCOM1, expanded normal procedures, it says:
G. After Take-Off Check
(1) Landing gear ........................................................Chec k retracted.
NOTE
During normal operations, landing gear and flap indications are normally occulted (removed
from EICAS) when the landing gear are stowed and the flaps are up.
At not less than VFTO + 5 KIAS:
(2) Flaps....................................................... .................. Set to 0°.
(3)
Note it says "not less than".
Also bear in mind that this is the checklist, which is intended to be used as a follow up after the event. The after takeoff checklist should not normally be read until the aircraft is well away from the airport since before that the crew should be concentrating on flying.
So flying a NADP profile in no way conflicts with the AFM, ensures obstacle clearance in the event of an engine failure and gives commonality of procedures between normal and OEI.
As I said before, the height trigger is to start acceleration and is only indirectly linked to flap retraction, and certainly should not be as low as 400ft.
In fact it is the rush to pull the flaps up quickly after takeoff which
Part of the problem is that training providers (I will not single out FSI since there are plenty of others) market themselves as teaching people all they need to know, and most pilots do not make the effort to find out how little the actually know.
A challenge for you all - how many of you have actually read the AFM and the FCOM (or equivalent) from cover to cover? You might be surprised at how much you find in there that is not as you were told in training - even on a factory course!
So let's start with the AFM.
All it says in the normal procedures section is the After Takeoff Checklist where it just says:
O. After Take-Off Check
(1) LDG GEAR lever .............UP
(2) FLAPS ................. Set to 0°
(3)
No mention of heights or speeds.
In the FCOM1, expanded normal procedures, it says:
G. After Take-Off Check
(1) Landing gear ........................................................Chec k retracted.
NOTE
During normal operations, landing gear and flap indications are normally occulted (removed
from EICAS) when the landing gear are stowed and the flaps are up.
At not less than VFTO + 5 KIAS:
(2) Flaps....................................................... .................. Set to 0°.
(3)
Note it says "not less than".
Also bear in mind that this is the checklist, which is intended to be used as a follow up after the event. The after takeoff checklist should not normally be read until the aircraft is well away from the airport since before that the crew should be concentrating on flying.
So flying a NADP profile in no way conflicts with the AFM, ensures obstacle clearance in the event of an engine failure and gives commonality of procedures between normal and OEI.
As I said before, the height trigger is to start acceleration and is only indirectly linked to flap retraction, and certainly should not be as low as 400ft.
In fact it is the rush to pull the flaps up quickly after takeoff which
came out of the mists of time as tribal-knowledge and has no place in modern ops.
A challenge for you all - how many of you have actually read the AFM and the FCOM (or equivalent) from cover to cover? You might be surprised at how much you find in there that is not as you were told in training - even on a factory course!
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Hello B200Drv
I feel a bit like I'm being led up the cul-de-sac of shame and slaughter but hey, in for a penny, in for a pound..
I can't think of any particular reason not to select flap up with the gear in transit - there's certainly no limitation I'm aware of. I've got 6 hydraulic packs going full chat at that point. The two that are powering system 3 raise the gear, the other four are split between system 1 and 2 and raise the flap (from memory). Have I missed the point?
Aerodynamically, I can't see why I wouldnt get the airframe clean when Bombardier tell me to.
What have I missed?
I feel a bit like I'm being led up the cul-de-sac of shame and slaughter but hey, in for a penny, in for a pound..
I can't think of any particular reason not to select flap up with the gear in transit - there's certainly no limitation I'm aware of. I've got 6 hydraulic packs going full chat at that point. The two that are powering system 3 raise the gear, the other four are split between system 1 and 2 and raise the flap (from memory). Have I missed the point?
Aerodynamically, I can't see why I wouldnt get the airframe clean when Bombardier tell me to.
What have I missed?
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the other four are split between system 1 and 2 and raise the flap (from memory)
Flaps are electric on all Challenger 600 series.
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bizjetjock - yep thats right, sorry, wasn't really thinking about it and I still dont really understand why its important in terms of a performance discussion. what have I missed? They are completely separate systems. What relation does it have to performance?
(should have remembered that really as the squirly whirly electric cable drive wound itself into a pig tail on one of the 601's I flew not that long ago and I had my head up its chuff looking at it... thats what happens if you answer a question without thinking properly!!)
you could be right, it could be the beer..
(should have remembered that really as the squirly whirly electric cable drive wound itself into a pig tail on one of the 601's I flew not that long ago and I had my head up its chuff looking at it... thats what happens if you answer a question without thinking properly!!)
you could be right, it could be the beer..
Last edited by tommoutrie; 20th Nov 2012 at 11:54.
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Biz jet, you'll upset Cessna if you say it was certified part 23. They voluntarily certified it part 25 for take off and landing and spend a bucket load of cash doing it.
I'm not certain I understand the thrust of the rest of your post. Yes you can fly both noise abatement profiles exactly as they are laid out and not contravene anything in the AFM. Is that a surprise? Thats how it should be. Certainly the 601 flies both profiles without any issue - you do get a pretty consistently high deck angle of approx 20 degrees but I don't really see why that's a problem. You could choose to follow the derate procedure if you want to make it more comfortable (its a bit of a faff in the 601 and my old company couldnt be bothered to include it in the Part B anyway).
I'm not certain I understand the thrust of the rest of your post. Yes you can fly both noise abatement profiles exactly as they are laid out and not contravene anything in the AFM. Is that a surprise? Thats how it should be. Certainly the 601 flies both profiles without any issue - you do get a pretty consistently high deck angle of approx 20 degrees but I don't really see why that's a problem. You could choose to follow the derate procedure if you want to make it more comfortable (its a bit of a faff in the 601 and my old company couldnt be bothered to include it in the Part B anyway).
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Can I bring us back to the central point? Lots of operators (I have worked for 3) have SOP's which encourage pilots to take off with the appropriate flap setting, go well through the speed at which they could select the flap up (sometimes by 50 kts or more) and take the flap up at 1500 feet just because its seen as a flap retraction platform.
Is this what anyone reading this thread does and do people think that's right or wrong?
Also, whats wrong with raising the flap when the manufacturer suggests? Where did a 400 foot height check come from? What I'm suggesting is that it doesnt make sense to have a height check at all for flap retraction. We should have a level acceleration platform available so that we can pitch level and accelerate if required but why is there a routinely accepted height check for flaps?
thats all I'm saying chaps, slightly surprised that everyone seems so negative about it. Do what you like, I don't really care. Tomorrows thesis is on the advantages of flying the ILS inverted so that you see the ground more easily on breakthrough.
Is this what anyone reading this thread does and do people think that's right or wrong?
Also, whats wrong with raising the flap when the manufacturer suggests? Where did a 400 foot height check come from? What I'm suggesting is that it doesnt make sense to have a height check at all for flap retraction. We should have a level acceleration platform available so that we can pitch level and accelerate if required but why is there a routinely accepted height check for flaps?
thats all I'm saying chaps, slightly surprised that everyone seems so negative about it. Do what you like, I don't really care. Tomorrows thesis is on the advantages of flying the ILS inverted so that you see the ground more easily on breakthrough.
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Biz jet, you'll upset Cessna if you say it was certified part 23. They voluntarily certified it part 25 for take off and landing and spend a bucket load of cash doing it.
My point really is that the manufacturer doesn't specify, so we have plenty of leeway without contradicting anything in the AFM.
At the same time as EU-OPS operators we are obliged to fly NADP's - it is not optional! (OPS1.235 or if you're getting really ahead then CAT.OP.MPA.130)
And that's before you get into any discussions about engine out procedures. Apart from the esoteric arguments about performance, I have plenty of times in training seen people get themselves into trouble by trying to fly their normal profile following an engine failure. So it is much better to have a procedure where you climb to the same acceleration altitude regardless of number of engines. The only difference is the speed you fly to get there.
And just for clarity, you are flying a speed up to the AA, not a fixed pitch or a VS.
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On a noise abatement departure we take off, pitch for V2+15 (or thereabouts), passing 800 feet reduce power a bit, put the autopilot in FLC, LNAV, at 1500 feet wind FLC up to the enroute climb speed of 190, as the aircraft passes V2+20 (normally somewhere around 160) select flaps up, and it climbs away at 190. Then, once clear of the terminal area and typically at around 3000 feet we dial in 250 kts and have a cup of tea.
Normal departure, pitch for 15 degrees, passing V2+20, flap up, when it gets to enroute climb speed 190 or 250 as brief take FLC. Thats not whats in my part B - whats in my part B is daft..
Normal departure, pitch for 15 degrees, passing V2+20, flap up, when it gets to enroute climb speed 190 or 250 as brief take FLC. Thats not whats in my part B - whats in my part B is daft..
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I think noise abatement is quite difficult to fly absolutely accurately and I also think it warrants a proper discussion on here. Its a difficult subject for business jets because hardly anyone does it correctly (well I don't think they do - I could be wrong)
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Thats not whats in my part B - whats in my part B is daft..