Flap retraction
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http://myaccount.dropsend.com/file/3e0e7c7fcf8cbc20
Final segment climb speed.
Thats all the data posted which proves your net climb gradients clean when you take flaps up at V2+20.
Would you like any more data?
Send me any scenarios you wish run that you think change the manufacturers AFM.
Fact is, what most people do is not in the AFM and what I have suggested to you is exactly what the people that make the planes want us to do. There is a clear divide here - somewhere along the line the message has become confused and we no longer deal with any engine failure case other than the one that is most critical. It is correct that we plan for that but it is not correct to then degrade the flight path performance of the aircraft by not doing what the manufacturers say.
Almost all of us - me included until recently - have been doing it wrong because we have been taught badly.
Final segment climb speed.
Thats all the data posted which proves your net climb gradients clean when you take flaps up at V2+20.
Would you like any more data?
Send me any scenarios you wish run that you think change the manufacturers AFM.
Fact is, what most people do is not in the AFM and what I have suggested to you is exactly what the people that make the planes want us to do. There is a clear divide here - somewhere along the line the message has become confused and we no longer deal with any engine failure case other than the one that is most critical. It is correct that we plan for that but it is not correct to then degrade the flight path performance of the aircraft by not doing what the manufacturers say.
Almost all of us - me included until recently - have been doing it wrong because we have been taught badly.
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Cough..
Its great that its in the commercial type you previously flew - which type was it?
An all engines flap retraction height is not in the Challenger manual, its not in the XLS manual, its not in the Lineage manual, its not in the Phenom manual, its not in the Citationjet manual, its not in the Hawker 125 series manual, and I don't understand what scares you. I've never seen an all engines flap retraction height in any flight manual ever. I've never seen a flap retraction height at all - only acceleration altitudes. If you don't need the level platform then no platform exists.
The obstacle clearance is irrelevent to the arguement because the take off performance calculation is exactly the same - the obstacle clearance and net take off flight path calculation is based on OEI at V1 so nothing has changed. What I think is misunderstood is the effect of retracting the flaps as per the manufacturers AFM and performance data. In fact, I'll go further. If you don't do it the way the manufacturer says, you are on unknown ground. What type do you fly and what departure profile do you use for a noise abatement and non noise departure? Lets see how compliant it is.
Explain exactly what scares you. I do the same perf calcs as anyone else - almost certainly a lot more as I cross check the FGP data. I then fly the aircraft as the flight manual states. Does it scare you that I don't simply copy what I learned on an airliner and apply it to a business jet? Does it scare you that I'm doing exactly what it says in the manual?
I've kind of had enough of tribal knowledge ruling this thread. Post the legislation that imposes a flap retraction height in the case of an all engines operating take off. Post the data which shows a flap retraction height as opposed to an acceleration altitude exists at all. Post any AFM procedure which states that exceeding V2 by 30, 40, 50 knots is acceptable practice and has no effect on aircraft performance. You need 1.25 V2 to have the flaps retracted on a challenger - thats what the speed to fly table gives you. Thats not even V2+20 so at V2+20 you have plenty of handling margin and thats probably why the speed was chosen. What you definitely dont have is any idea how much you have degraded the flight path by if you dont raise the flap.
bizarre that you all think this is sensible but don't have any data or any statements in the AFM that show it!
Its great that its in the commercial type you previously flew - which type was it?
An all engines flap retraction height is not in the Challenger manual, its not in the XLS manual, its not in the Lineage manual, its not in the Phenom manual, its not in the Citationjet manual, its not in the Hawker 125 series manual, and I don't understand what scares you. I've never seen an all engines flap retraction height in any flight manual ever. I've never seen a flap retraction height at all - only acceleration altitudes. If you don't need the level platform then no platform exists.
The obstacle clearance is irrelevent to the arguement because the take off performance calculation is exactly the same - the obstacle clearance and net take off flight path calculation is based on OEI at V1 so nothing has changed. What I think is misunderstood is the effect of retracting the flaps as per the manufacturers AFM and performance data. In fact, I'll go further. If you don't do it the way the manufacturer says, you are on unknown ground. What type do you fly and what departure profile do you use for a noise abatement and non noise departure? Lets see how compliant it is.
Explain exactly what scares you. I do the same perf calcs as anyone else - almost certainly a lot more as I cross check the FGP data. I then fly the aircraft as the flight manual states. Does it scare you that I don't simply copy what I learned on an airliner and apply it to a business jet? Does it scare you that I'm doing exactly what it says in the manual?
I've kind of had enough of tribal knowledge ruling this thread. Post the legislation that imposes a flap retraction height in the case of an all engines operating take off. Post the data which shows a flap retraction height as opposed to an acceleration altitude exists at all. Post any AFM procedure which states that exceeding V2 by 30, 40, 50 knots is acceptable practice and has no effect on aircraft performance. You need 1.25 V2 to have the flaps retracted on a challenger - thats what the speed to fly table gives you. Thats not even V2+20 so at V2+20 you have plenty of handling margin and thats probably why the speed was chosen. What you definitely dont have is any idea how much you have degraded the flight path by if you dont raise the flap.
bizarre that you all think this is sensible but don't have any data or any statements in the AFM that show it!
Last edited by tommoutrie; 27th Nov 2012 at 20:40.
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Cough.
Post the section of your AFM that discusses an all engines operating flap retraction height. I've had a bet accepted for a thousand pounds that data did not exist for a clean climb below 400 feet and I've posted it. From the AFM. I'll directly issue a double or quits to you if you like that what you do on a normal departure does not come from your AFM. I'm going to suggest it comes from Flight Safety.
Are you up for the double or quits? Are you sure what you are doing is what the people who built the plane think you're doing and that I'm nuts?
If so, bets on.
Post the section of your AFM that discusses an all engines operating flap retraction height. I've had a bet accepted for a thousand pounds that data did not exist for a clean climb below 400 feet and I've posted it. From the AFM. I'll directly issue a double or quits to you if you like that what you do on a normal departure does not come from your AFM. I'm going to suggest it comes from Flight Safety.
Are you up for the double or quits? Are you sure what you are doing is what the people who built the plane think you're doing and that I'm nuts?
If so, bets on.
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by the way, saying I'm up for a Darwin award and I make stuff up when it comes straight out of the manual is offensive.
The bets still open to anyone else who wants to take it.
The bets still open to anyone else who wants to take it.
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On the 737 and with the way our performance is set up any obstacle and engine failure between V1 and passing MSA is considered. To be safe during that time we have to stick to the calculated flap schedule which is based on heights. V2 + 20 can be up to 50kts below minimum clean speed, so pitching down to accelerate those 50kts upon reaching V2 +20 will immediately invalidate any obstacle clearance (not to mention any required NADP). The furthest obstacle considered I've seen was around 30NM from the departure end of he runway, our EFB tells us something like that just for information. Acceleration heights are usually different for all engines operating and one engine out, both have to be filled into the Take Off Ref page 2 during preflight, same as the thrust reduction height.
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Tom, you're getting increasingly strident on here and all you're doing is proving the old adage that a little knowledge is a dangerous thing.
You keep banging on about one graph in the AFM as if that were the only factor, when I and others have pointed out to you that several other things, not least EU-OPS, are the driving factors.
To give a couple of similar examples:
1. According to the AFM I can join the visual circuit at Oxford at 300 knots; you know perfectly well, though, that the Rules of the Air limit us to 250 below 10k and that for practical reasons of preparing for the final approach and fitting in with other traffic we want to be back nearer 150knots and configured appropriately. By your logic I should go for the higher speed clean and damn the rules and other airspace users.
2. Where in the AFM does it say that I can't land in 100m RVR? By your logic because it doesn't say it in the AFM I can go ahead and do that if I want.
The reason why EU-OPS and every equivalent regulation round the world says you must follow your Part B procedures is precisely to stop people who've read one bit of information in isolation coming up with their own hare-brained procedures. And once again, you must follow your Part B; it's not a case of " maybe if I feel like agreeeing with it I'll do it". If you think your Part B isn't correct, then raise a fuss with your company until they either explain why it's written the way it is or change it if in fact your point is correct.
And finally, again this has been written before but you choose to ignore it because it doesn't fit your little theory, the heights mentioned in some AFM's and many SOP's are not retraction heights; they are acceleration heights, except that normally on two engines in high performance bizjets you are already above the minimum retraction speed when you get there. Just because many people refer to them incorrectly due to poor training does not invalidate the procedure.
You keep banging on about one graph in the AFM as if that were the only factor, when I and others have pointed out to you that several other things, not least EU-OPS, are the driving factors.
To give a couple of similar examples:
1. According to the AFM I can join the visual circuit at Oxford at 300 knots; you know perfectly well, though, that the Rules of the Air limit us to 250 below 10k and that for practical reasons of preparing for the final approach and fitting in with other traffic we want to be back nearer 150knots and configured appropriately. By your logic I should go for the higher speed clean and damn the rules and other airspace users.
2. Where in the AFM does it say that I can't land in 100m RVR? By your logic because it doesn't say it in the AFM I can go ahead and do that if I want.
The reason why EU-OPS and every equivalent regulation round the world says you must follow your Part B procedures is precisely to stop people who've read one bit of information in isolation coming up with their own hare-brained procedures. And once again, you must follow your Part B; it's not a case of " maybe if I feel like agreeeing with it I'll do it". If you think your Part B isn't correct, then raise a fuss with your company until they either explain why it's written the way it is or change it if in fact your point is correct.
And finally, again this has been written before but you choose to ignore it because it doesn't fit your little theory, the heights mentioned in some AFM's and many SOP's are not retraction heights; they are acceleration heights, except that normally on two engines in high performance bizjets you are already above the minimum retraction speed when you get there. Just because many people refer to them incorrectly due to poor training does not invalidate the procedure.
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Tom,
I think that BizJetJock has highlighted an important issue. We, as commercial pilots, are bound by several parameters: firstly, what the AFM says that the aircraft is capable of, secondly what the Regulating Authority says is legal, and thirdly what the AOC of your particular company has decided to do (potentially more restrictive than the other two).
Rightly or wrongly, we are bound by the AOC, which is an evolving document and should, with time, address any anomalies that might occur. On the Hawker in my operation, the Authority, the AFM and the AOC allow either flap 0 or flap15 take-offs. The AFM publishes second segment climb profiles for both and under certain circumstances we get a better rate and gradient using flap 0. However, the AFM doesn't publish a profile for a combination of flap 0 and flap 15 to 1500', therefore we have to use one or the other.
The practical advantage of flying flap 15 to 1500' with both engines operating is that the aircraft is already configured such that it will give a known climb gradient if one engine fails at any point between V1 and 1500' agl provided that climb power is set on the operating engine and the aircraft is pitched to climb at V2. Of course, with two engines operating we will follow the SID which, unless stated otherwise, has a Terps climb gradient requirement of 300' per nm or so to clear obstacles (or 900'pm at 180 kts).
Therefore, all you need to do with a fully functioning aircraft is to climb at a sensible speed and adjust rate of climb with power such that you at least achieve the required SID climb gradient. If an engine fails before 1500', apply climb power and pitch for V2. However, if your AOC says that you must leave climb power set until 1500' regardless of how many engines are operating just in case one fails and you forget to apply climb power to the live one then you have another set of problems to contend with, particularly on a cold day out of Farnborough with an initial level-off at 2200 agl !
Of course, without an AOC, operators are only bound by the law and the AFM. It is often the ambiguous wording of AOCs that causes pilots to fly illogical procedures and these anomalies should be highlighted to the Operator for possible amendment.
AP
I think that BizJetJock has highlighted an important issue. We, as commercial pilots, are bound by several parameters: firstly, what the AFM says that the aircraft is capable of, secondly what the Regulating Authority says is legal, and thirdly what the AOC of your particular company has decided to do (potentially more restrictive than the other two).
Rightly or wrongly, we are bound by the AOC, which is an evolving document and should, with time, address any anomalies that might occur. On the Hawker in my operation, the Authority, the AFM and the AOC allow either flap 0 or flap15 take-offs. The AFM publishes second segment climb profiles for both and under certain circumstances we get a better rate and gradient using flap 0. However, the AFM doesn't publish a profile for a combination of flap 0 and flap 15 to 1500', therefore we have to use one or the other.
The practical advantage of flying flap 15 to 1500' with both engines operating is that the aircraft is already configured such that it will give a known climb gradient if one engine fails at any point between V1 and 1500' agl provided that climb power is set on the operating engine and the aircraft is pitched to climb at V2. Of course, with two engines operating we will follow the SID which, unless stated otherwise, has a Terps climb gradient requirement of 300' per nm or so to clear obstacles (or 900'pm at 180 kts).
Therefore, all you need to do with a fully functioning aircraft is to climb at a sensible speed and adjust rate of climb with power such that you at least achieve the required SID climb gradient. If an engine fails before 1500', apply climb power and pitch for V2. However, if your AOC says that you must leave climb power set until 1500' regardless of how many engines are operating just in case one fails and you forget to apply climb power to the live one then you have another set of problems to contend with, particularly on a cold day out of Farnborough with an initial level-off at 2200 agl !
Of course, without an AOC, operators are only bound by the law and the AFM. It is often the ambiguous wording of AOCs that causes pilots to fly illogical procedures and these anomalies should be highlighted to the Operator for possible amendment.
AP
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Tom,
We have the same profile for both my types, the 737 and 320. In both types the profile is the same, around v2-v2+20 until minimum 400' (Though our thrust reduction alt is higher) then select climb thrust and accelerate. If we are using full thrust on departure, or given a positive windshear then I will pitch to maintain a stable climb speed within those values. Gin and tonic isn't served on take off.
The 400' reference is found the the QRH for the all engines running, normal takeoff profile for both airbus and Boeing.
As for the noise profiles, we comply with them as written.
We have the same profile for both my types, the 737 and 320. In both types the profile is the same, around v2-v2+20 until minimum 400' (Though our thrust reduction alt is higher) then select climb thrust and accelerate. If we are using full thrust on departure, or given a positive windshear then I will pitch to maintain a stable climb speed within those values. Gin and tonic isn't served on take off.
The 400' reference is found the the QRH for the all engines running, normal takeoff profile for both airbus and Boeing.
As for the noise profiles, we comply with them as written.
Last edited by Cough; 28th Nov 2012 at 10:28.
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evening Cough
Thats exactly in accordance with what I've been trying to raise as you are flying to the speeds suggested in the AFM. What I'm trying to raise is the fact that the majority of business jet pilots will routinely exceed the flap up speed by 30, 40, 50 knots, sometimes even more, because they believe there is a mandated flap retraction height. If a particular manufacturer has imposed one (I've seen it in the Boeing training guide for the 737 and 757 and many 737 operators impose an MFRA of 1000 feet) then thats fine and you have to comply with it but nobody should make the mistake of believing that its in EU-OPS or EASA (my knowledge of EU-OPS is pretty good, my knowledge of EASA is not so good) until a reference is found. I cannot find one, I have asked many times if any pilots can quote one.
thanks for your input - haven't flown airliners and its interesting that this difference exists.
Thats exactly in accordance with what I've been trying to raise as you are flying to the speeds suggested in the AFM. What I'm trying to raise is the fact that the majority of business jet pilots will routinely exceed the flap up speed by 30, 40, 50 knots, sometimes even more, because they believe there is a mandated flap retraction height. If a particular manufacturer has imposed one (I've seen it in the Boeing training guide for the 737 and 757 and many 737 operators impose an MFRA of 1000 feet) then thats fine and you have to comply with it but nobody should make the mistake of believing that its in EU-OPS or EASA (my knowledge of EU-OPS is pretty good, my knowledge of EASA is not so good) until a reference is found. I cannot find one, I have asked many times if any pilots can quote one.
thanks for your input - haven't flown airliners and its interesting that this difference exists.
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400 feet is not mentioned in the AFM of any type flown by my company. I'm not at all sure that it is best practice - I think its tribal knowledge and promulgated by training organisations on types for which its not appropriate. Its a bad place for to use as a trigger for retracting the flaps precisely because its a common place for things to start happening - turning on a SID for instance, or getting told on the radio to contact another frequency. A height check is just not logical for moving flaps - the wing configuration is only dependent on speed so what is the logic? Its utter rubbish to say "you might move the wrong lever" otherwise it would be mandated that you leave the gear down and you can't go around under 400 feet. You degrade the climb performance of the aircraft in both the all engines operating and one engine inoperative conditions if you fail to retract the flaps once you are through the retraction speed (otherwise what is the logic in retracting them at all?).
The chap with the Hawker has the data - compare a typical take off with flap and without. Look at the OEI net take off climb chart for the same conditions. Which has the better gradient? If its clean, take off clean. If you cant take off clean because of runway limitations, why don't you raise the flap at V2+10 and benefit from the improved climb gradient at that point? What is the logic of climbing against drag? As soon as the flaps start to travel the aircraft is trending from the net gradient flapped to the net gradient clean so what stops you doing it? I'm getting a Hawker manual from a colleague today so I can see if its true that Hawker mandate that you can't do this in the AFM.
The argument about needing "maneuvering margin" when clean is also bogus. The minimum clean wing speed on a Challenger is 1.25Vs. At low weights this is V2+4, at high weights its V2+7. However, the manufacturer says flaps up at V2+20 - the margin is already there which is why they set that speed.
So far nobody has posted a regulation and nobody has posted an AFM reference which states this (I take Cough's comments on the Boeing and the Airbus because I have seen 400 feet and 1000 feet referred to in training notes but I very much doubt any operator of an airliner would exceed the minimum flap retraction speeds by 20 to 50 knots in the way that business jets routinely do).
Please, somebody, post the rule which prevents the flap retraction before 400 feet and, failing that, the section of the AFM which prevents the flap retraction during an all engines operating take off when passing V2+X. If that bit is hard to find, please explain why we bother to take the flaps up at 1500 feet if the climb is better with flap?
ta
The chap with the Hawker has the data - compare a typical take off with flap and without. Look at the OEI net take off climb chart for the same conditions. Which has the better gradient? If its clean, take off clean. If you cant take off clean because of runway limitations, why don't you raise the flap at V2+10 and benefit from the improved climb gradient at that point? What is the logic of climbing against drag? As soon as the flaps start to travel the aircraft is trending from the net gradient flapped to the net gradient clean so what stops you doing it? I'm getting a Hawker manual from a colleague today so I can see if its true that Hawker mandate that you can't do this in the AFM.
The argument about needing "maneuvering margin" when clean is also bogus. The minimum clean wing speed on a Challenger is 1.25Vs. At low weights this is V2+4, at high weights its V2+7. However, the manufacturer says flaps up at V2+20 - the margin is already there which is why they set that speed.
So far nobody has posted a regulation and nobody has posted an AFM reference which states this (I take Cough's comments on the Boeing and the Airbus because I have seen 400 feet and 1000 feet referred to in training notes but I very much doubt any operator of an airliner would exceed the minimum flap retraction speeds by 20 to 50 knots in the way that business jets routinely do).
Please, somebody, post the rule which prevents the flap retraction before 400 feet and, failing that, the section of the AFM which prevents the flap retraction during an all engines operating take off when passing V2+X. If that bit is hard to find, please explain why we bother to take the flaps up at 1500 feet if the climb is better with flap?
ta
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So far nobody has posted a regulation
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they quoted a section of FAR25 without quoting the conditions one of which is a failure of the critical powerplant at V1. How is this relevant if you have planned for that failure but actually achieved V2+X and are climbing with all engines operating to that point?
Let me stress again because some people seem to be concerned that the planning changes. The planning remains performance group A - nothing has changed. In the event of a failure of a powerplant at any stage the actual flight path exceeds that of the net take off path calculated (as shown by the two charts I posted).
What I've been suggesting is that we follow the AFM. What most pilots are doing is making up procedures which rely on falling back to the most degraded flight path possible and I have no idea why they are not following the manufacturers guidelines. I'm being accused of making up procedures - the opposite is true. I'm suggesting that we read the AFM properly and do exactly what it says rather than come up with utter rubbish like climbing against drag to control the speed, delaying flap retraction so that theres "handling margin" and all these other bogus arguments which would be in the flight manual if they were true.
If you are going to quote regulations you have to understand them. FAR25 is for certification and nothing I've said changes what you do if an engine fails at V1. But the lack of aerodynamic understanding and made up rules that people are applying simply because they have never even considered failures at other points in the climb is astonishing. Where have you got your procedures for an engine failure at 500 feet with V2+50 and take off flap set? It simply doesn't exist! Its nowhere and you made it up! More likely, someone else made it up and you and others follow it blindly without thinking about it. What is the problem with following the AFM? I simply don't understand what the argument is against doing this.
If its in the AFM then fine (cough and his 737 and 320, its very good that he's read it and knows its in there) but is isnt in the AFM for the types I have flown or written manuals for. Is it actually in the AFM for your aircraft or do you just think it is?
Let me stress again because some people seem to be concerned that the planning changes. The planning remains performance group A - nothing has changed. In the event of a failure of a powerplant at any stage the actual flight path exceeds that of the net take off path calculated (as shown by the two charts I posted).
What I've been suggesting is that we follow the AFM. What most pilots are doing is making up procedures which rely on falling back to the most degraded flight path possible and I have no idea why they are not following the manufacturers guidelines. I'm being accused of making up procedures - the opposite is true. I'm suggesting that we read the AFM properly and do exactly what it says rather than come up with utter rubbish like climbing against drag to control the speed, delaying flap retraction so that theres "handling margin" and all these other bogus arguments which would be in the flight manual if they were true.
If you are going to quote regulations you have to understand them. FAR25 is for certification and nothing I've said changes what you do if an engine fails at V1. But the lack of aerodynamic understanding and made up rules that people are applying simply because they have never even considered failures at other points in the climb is astonishing. Where have you got your procedures for an engine failure at 500 feet with V2+50 and take off flap set? It simply doesn't exist! Its nowhere and you made it up! More likely, someone else made it up and you and others follow it blindly without thinking about it. What is the problem with following the AFM? I simply don't understand what the argument is against doing this.
If its in the AFM then fine (cough and his 737 and 320, its very good that he's read it and knows its in there) but is isnt in the AFM for the types I have flown or written manuals for. Is it actually in the AFM for your aircraft or do you just think it is?
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ballyeck 297 posts including mine - on flap retraction, Im with poster number 10 of referring to handling the big jets from a bygone era but still very relevant . Im pragmatic anything less than 400ft its a bit early (which is all the fuss is about I think?) and unless your doing the NAPD 1 or 2 then if there not up by 1500ft tell me otherwise I may think you've forgotten them anyway I don't loose too much sleep I'll stick with the phrase 'height and speed good' before I my hand on the lever. 400,500, 1000, 1300 1500, 3000ft. Whatever I dont loose to much sleep ; I follow whatever SOP provided has its been said many many times so long as its in the AFM
1st prize if this makes 300 posts
1st prize if this makes 300 posts
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What do you fly? Is it in the AFM? Where? Can you post it?
If you cant move the correct lever below 400 feet you can't go around at any height below that so you have to modify your part B. You have to move flap at 200 feet and the gear shortly afterwards on positive rate. How can you do that below 400 feet?
just doesn't add up
If you cant move the correct lever below 400 feet you can't go around at any height below that so you have to modify your part B. You have to move flap at 200 feet and the gear shortly afterwards on positive rate. How can you do that below 400 feet?
just doesn't add up
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EU-OPS has also been quoted several times and you have completely ignored it.
The procedure for an engine failure at 500 feet is to continue the climb to acceleration altitude in the takeoff configuration, reducing the speed to V2 +10 if you are already above that speed. This is specified in the 604 and 605 manuals, but not in the 601.
I'll turn your question around. Where in the AFM does it say we should retract the flaps as soon as aerodynamically possible? You know perfectly well that it doesn't say that anywhere, so your bleating about following the AFM doesn't hold water.
I'm coming to the conclusion that the real problem is the African sun is getting to you...
The procedure for an engine failure at 500 feet is to continue the climb to acceleration altitude in the takeoff configuration, reducing the speed to V2 +10 if you are already above that speed. This is specified in the 604 and 605 manuals, but not in the 601.
I'll turn your question around. Where in the AFM does it say we should retract the flaps as soon as aerodynamically possible? You know perfectly well that it doesn't say that anywhere, so your bleating about following the AFM doesn't hold water.
I'm coming to the conclusion that the real problem is the African sun is getting to you...
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Tom
Put simply, second segment climb finishes at 1500' agl with the required gradient being predicated on the worst case scenario, an engine failure at V1. If an engine fails after V1 but before VFTO then, if you pitch to V2, you will achieve a known gradient starting from a higher point, which is a bonus. If you have already accelerated to VFTO (around 160kts in the Hawker) and have retracted flaps before an engine fails then the Hawker AFM advises to continue climb at that speed until clear of obstacles. In other words, for the Hawker, second segment climb gradient is assured below 1500' as long as the flaps are retracted at or above VFTO and that speed is maintained until 1500'. However, there is no harm in leaving flaps at 15 with all engines running until 1500' if that is what your AOC demands. If the resultant deck angle bothers you (max pitch is 20 degrees from the Hawker AFM) then all you need to do is reduce power until you have a happy balance between deck angle and rate of climb. If you pitch for VFTO then you will have a limited drag penalty. If you pitch for anything less than 220 kts then you won't over speed the flaps. 160-180 kts and 90 per cent N1 works well for the Hawker, giving a good rate of climb and pleasant deck angle. I am slightly confused about all these pilots who are allegedly over-speeding the flaps; if both engines are running and you pitch for VFTO, controlling ROC with power, how can you over- speed the flaps?
Finally, the Flight Safety manual suggests 400' and VFTO as the flap retraction point, presumably as a belt and braces safety measure. There is no mention of 400' in the approved AFM, although the two are often achieved at about the same time. The AFM for your type will tell you how the aircraft should be flown to achieve a desired outcome. Your Authority and company AOC may require a different procedure, possibly for standardisation reasons. If there is a situation whereby the AOC requirements cause your type to be flown outside the limitations of the AFM or in an unnecessarily inefficient manner then you should make this known to your bosses such that the AOC can be amended.
AP
Put simply, second segment climb finishes at 1500' agl with the required gradient being predicated on the worst case scenario, an engine failure at V1. If an engine fails after V1 but before VFTO then, if you pitch to V2, you will achieve a known gradient starting from a higher point, which is a bonus. If you have already accelerated to VFTO (around 160kts in the Hawker) and have retracted flaps before an engine fails then the Hawker AFM advises to continue climb at that speed until clear of obstacles. In other words, for the Hawker, second segment climb gradient is assured below 1500' as long as the flaps are retracted at or above VFTO and that speed is maintained until 1500'. However, there is no harm in leaving flaps at 15 with all engines running until 1500' if that is what your AOC demands. If the resultant deck angle bothers you (max pitch is 20 degrees from the Hawker AFM) then all you need to do is reduce power until you have a happy balance between deck angle and rate of climb. If you pitch for VFTO then you will have a limited drag penalty. If you pitch for anything less than 220 kts then you won't over speed the flaps. 160-180 kts and 90 per cent N1 works well for the Hawker, giving a good rate of climb and pleasant deck angle. I am slightly confused about all these pilots who are allegedly over-speeding the flaps; if both engines are running and you pitch for VFTO, controlling ROC with power, how can you over- speed the flaps?
Finally, the Flight Safety manual suggests 400' and VFTO as the flap retraction point, presumably as a belt and braces safety measure. There is no mention of 400' in the approved AFM, although the two are often achieved at about the same time. The AFM for your type will tell you how the aircraft should be flown to achieve a desired outcome. Your Authority and company AOC may require a different procedure, possibly for standardisation reasons. If there is a situation whereby the AOC requirements cause your type to be flown outside the limitations of the AFM or in an unnecessarily inefficient manner then you should make this known to your bosses such that the AOC can be amended.
AP
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Put simply, second segment climb finishes at 1500' agl
It absolutely does not. This is demonstration of how badly taught this is. Second segment ends at flap retraction. It has nothing whatsoever to do with height. In the event that you lack sufficient power to accelerate to flap retraction speed your aircraft is certified to use certain acceleration platforms and that varies. The most commonly used is 1500 feet but some aircraft use 400 feet. Because the gradient achieved is better clean than flapped, it is permissible and sometimes essential to reduce the platform from 1500 feet where obstacle clearance is not an issue. Just to confirm. Second segment has nothing at all to do with height and on an all engines operating departure you are final segment when you retract the flaps and enroute segment when you have accelerated to your enroute speed.
with the required gradient being predicated on the worst case scenario, an engine failure at V1.
This is true and your performance calculations are predicated on this case but you have tables in the Hawker AFM for flapless departures. Therefore, if you depart in a flapped condition but make it with both engines to flap retraction you can use the flapless gradient from that point which will outperform the flapped gradient. There is no third (level) segment for acceleration because the excess power of all engines operating has both climbed and accelerated you to the retraction speed.
If an engine fails after V1 but before VFTO then, if you pitch to V2, you will achieve a known gradient starting from a higher point, which is a bonus.
Correct. This is, however, unquantifiable without all engines operating tables which we commonly don't have.
If you have already accelerated to VFTO (around 160kts in the Hawker) and have retracted flaps before an engine fails then the Hawker AFM advises to continue climb at that speed until clear of obstacles. In other words, for the Hawker, second segment climb gradient is assured below 1500' as long as the flaps are retracted at or above VFTO and that speed is maintained until 1500'.
I dont have a Hawker AFM but am hopefully getting one later today. Could you post or email me the reference where I can find that in the AFM?
However, there is no harm in leaving flaps at 15 with all engines running until 1500' if that is what your AOC demands.
If you remain below the declared speed for noise abatement departures and thats what you are doing you are correct.
If you are departing without consideration to noise then you are climbing at an unknown gradient (especially if you have reduced power) and would have calculations to make in the event of an engine failure. For instance, if you are on a departure requiring a SID gradient of 5% and you chose to climb at 1000fpm at 200 kts because its comfortable you are under the required SID gradient. If you then fail an engine you will have an element of "zoom climb" while you reduce speed to V2 but it is unquantifiable. So you are under.
If the resultant deck angle bothers you (max pitch is 20 degrees from the Hawker AFM) then all you need to do is reduce power until you have a happy balance between deck angle and rate of climb. If you pitch for VFTO then you will have a limited drag penalty.
This is sort of true but you will have even less of a drag penalty if you are clean. You also have the advantage of an aircraft thats easier to fly in the event of an engine failure and you have no third segment to pitch for. You are already final segment (in fact, because of speed, enroute segment)
If you pitch for anything less than 220 kts then you won't over speed the flaps.
True, but as discussed before you are potentially degrading the climb gradient to a point where you are below the required.
160-180 kts and 90 per cent N1 works well for the Hawker, giving a good rate of climb and pleasant deck angle.
You are wasting fuel against extra drag and you are making more noise over the ground. There is no benefit to leaving the flaps down at that speed.
I am slightly confused about all these pilots who are allegedly over-speeding the flaps; if both engines are running and you pitch for VFTO, controlling ROC with power, how can you over- speed the flaps?
Nobody has mentioned flap overspeed.
Finally, the Flight Safety manual suggests 400' This is a Flight Safety SOP.
and VFTO as the flap retraction point, presumably as a belt and braces safety measure.
absolutely right - this is a presumption. It isn't, as you said, in the AFM
There is no mention of 400' in the approved AFM,
oh, there you go..
although the two are often achieved at about the same time.
This may or may not be true for your type (I would think it depends a lot on load, temperature, departure elevation etc.
The AFM for your type will tell you how the aircraft should be flown to achieve a desired outcome.
Absolutely right, I'm suggesting we follow it.
Your Authority and company AOC may require a different procedure, possibly for standardisation reasons.
This is also possible but quite how the Authority overides the AFM I really don't know. Right at the beginning of most company operating manuals it says something like:-
Each aeroplane is operated in compliance with the terms of the Operations Manual (OM), its Certificate of Airworthiness and within the approved limitations contained in its Aeroplane Flight Manual (AFM).
All operations personnel involved in the dispatch or conduct of a flight must be familiar with the laws, regulations and procedures pertinent to the performance of their duties, including those of the States in which operations are conducted.
The relevant personnel shall adhere to the rules, regulations, instructions and information contained in the OM at all times. However nothing shall keep the personnel from exercising their own best judgment during any irregularity for which the OM gives no provisions or in an emergency situation.
The rules and regulations laid down in the OM (Part A to D) do not overrule any State law or the instructions of the aeroplane’s manufacturer as laid down in their respective Aeroplane Flight Manual. If there is a discrepancy between this manual and any regulation, the Chief Pilot (CP) must be informed immediately.
If there is a situation whereby the AOC requirements cause your type to be flown outside the limitations of the AFM or in an unnecessarily inefficient manner then you should make this known to your bosses such that the AOC can be amended.
Further to that, if there is a situation where the AOC requires the aircraft to be flown in such a manner the AFM is the manual that your ops manual tells you to follow.
It absolutely does not. This is demonstration of how badly taught this is. Second segment ends at flap retraction. It has nothing whatsoever to do with height. In the event that you lack sufficient power to accelerate to flap retraction speed your aircraft is certified to use certain acceleration platforms and that varies. The most commonly used is 1500 feet but some aircraft use 400 feet. Because the gradient achieved is better clean than flapped, it is permissible and sometimes essential to reduce the platform from 1500 feet where obstacle clearance is not an issue. Just to confirm. Second segment has nothing at all to do with height and on an all engines operating departure you are final segment when you retract the flaps and enroute segment when you have accelerated to your enroute speed.
with the required gradient being predicated on the worst case scenario, an engine failure at V1.
This is true and your performance calculations are predicated on this case but you have tables in the Hawker AFM for flapless departures. Therefore, if you depart in a flapped condition but make it with both engines to flap retraction you can use the flapless gradient from that point which will outperform the flapped gradient. There is no third (level) segment for acceleration because the excess power of all engines operating has both climbed and accelerated you to the retraction speed.
If an engine fails after V1 but before VFTO then, if you pitch to V2, you will achieve a known gradient starting from a higher point, which is a bonus.
Correct. This is, however, unquantifiable without all engines operating tables which we commonly don't have.
If you have already accelerated to VFTO (around 160kts in the Hawker) and have retracted flaps before an engine fails then the Hawker AFM advises to continue climb at that speed until clear of obstacles. In other words, for the Hawker, second segment climb gradient is assured below 1500' as long as the flaps are retracted at or above VFTO and that speed is maintained until 1500'.
I dont have a Hawker AFM but am hopefully getting one later today. Could you post or email me the reference where I can find that in the AFM?
However, there is no harm in leaving flaps at 15 with all engines running until 1500' if that is what your AOC demands.
If you remain below the declared speed for noise abatement departures and thats what you are doing you are correct.
If you are departing without consideration to noise then you are climbing at an unknown gradient (especially if you have reduced power) and would have calculations to make in the event of an engine failure. For instance, if you are on a departure requiring a SID gradient of 5% and you chose to climb at 1000fpm at 200 kts because its comfortable you are under the required SID gradient. If you then fail an engine you will have an element of "zoom climb" while you reduce speed to V2 but it is unquantifiable. So you are under.
If the resultant deck angle bothers you (max pitch is 20 degrees from the Hawker AFM) then all you need to do is reduce power until you have a happy balance between deck angle and rate of climb. If you pitch for VFTO then you will have a limited drag penalty.
This is sort of true but you will have even less of a drag penalty if you are clean. You also have the advantage of an aircraft thats easier to fly in the event of an engine failure and you have no third segment to pitch for. You are already final segment (in fact, because of speed, enroute segment)
If you pitch for anything less than 220 kts then you won't over speed the flaps.
True, but as discussed before you are potentially degrading the climb gradient to a point where you are below the required.
160-180 kts and 90 per cent N1 works well for the Hawker, giving a good rate of climb and pleasant deck angle.
You are wasting fuel against extra drag and you are making more noise over the ground. There is no benefit to leaving the flaps down at that speed.
I am slightly confused about all these pilots who are allegedly over-speeding the flaps; if both engines are running and you pitch for VFTO, controlling ROC with power, how can you over- speed the flaps?
Nobody has mentioned flap overspeed.
Finally, the Flight Safety manual suggests 400' This is a Flight Safety SOP.
and VFTO as the flap retraction point, presumably as a belt and braces safety measure.
absolutely right - this is a presumption. It isn't, as you said, in the AFM
There is no mention of 400' in the approved AFM,
oh, there you go..
although the two are often achieved at about the same time.
This may or may not be true for your type (I would think it depends a lot on load, temperature, departure elevation etc.
The AFM for your type will tell you how the aircraft should be flown to achieve a desired outcome.
Absolutely right, I'm suggesting we follow it.
Your Authority and company AOC may require a different procedure, possibly for standardisation reasons.
This is also possible but quite how the Authority overides the AFM I really don't know. Right at the beginning of most company operating manuals it says something like:-
Each aeroplane is operated in compliance with the terms of the Operations Manual (OM), its Certificate of Airworthiness and within the approved limitations contained in its Aeroplane Flight Manual (AFM).
All operations personnel involved in the dispatch or conduct of a flight must be familiar with the laws, regulations and procedures pertinent to the performance of their duties, including those of the States in which operations are conducted.
The relevant personnel shall adhere to the rules, regulations, instructions and information contained in the OM at all times. However nothing shall keep the personnel from exercising their own best judgment during any irregularity for which the OM gives no provisions or in an emergency situation.
The rules and regulations laid down in the OM (Part A to D) do not overrule any State law or the instructions of the aeroplane’s manufacturer as laid down in their respective Aeroplane Flight Manual. If there is a discrepancy between this manual and any regulation, the Chief Pilot (CP) must be informed immediately.
If there is a situation whereby the AOC requirements cause your type to be flown outside the limitations of the AFM or in an unnecessarily inefficient manner then you should make this known to your bosses such that the AOC can be amended.
Further to that, if there is a situation where the AOC requires the aircraft to be flown in such a manner the AFM is the manual that your ops manual tells you to follow.
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Tom
From the Hawker manual re: second segment climb: "this extends from 35 feet to a height of 1500 feet or until the three and a half minute point is reached, whichever occurs first"
However, the manual also states "the charts in this sub-section (net take-off flight path) are provided to enable a complete net take-off flight path to be constructed........once it has been established beyond doubt that all obstacles will be cleared, there is no need to proceed further with the calculation."
That is what the manual for my aircraft says and 1500' is what my company and performance programme use for the end of the second segment regardless of clearing all known obstacles prior to that.
You really are getting your knickers in a twist over very little in my opinion. The time taken to 1500' with all engines operating is a matter of seconds in my type anyway so any potential unnecessary drag penalty by leaving 1st stage of flap set is there for such a short period of time as to be inconsequential. Maybe you should see if your type allows flap 0 take-offs; then you could rest easy.
Personally, I fly the profiles required by the AOC where specified and according to the flight manual and airmanship where not. What else can we do?
AP
From the Hawker manual re: second segment climb: "this extends from 35 feet to a height of 1500 feet or until the three and a half minute point is reached, whichever occurs first"
However, the manual also states "the charts in this sub-section (net take-off flight path) are provided to enable a complete net take-off flight path to be constructed........once it has been established beyond doubt that all obstacles will be cleared, there is no need to proceed further with the calculation."
That is what the manual for my aircraft says and 1500' is what my company and performance programme use for the end of the second segment regardless of clearing all known obstacles prior to that.
You really are getting your knickers in a twist over very little in my opinion. The time taken to 1500' with all engines operating is a matter of seconds in my type anyway so any potential unnecessary drag penalty by leaving 1st stage of flap set is there for such a short period of time as to be inconsequential. Maybe you should see if your type allows flap 0 take-offs; then you could rest easy.
Personally, I fly the profiles required by the AOC where specified and according to the flight manual and airmanship where not. What else can we do?
AP
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Sorry, Tom, indeed you did not say that pilots are routinely over speeding flaps but that they are routinely over speeding minimum retract speed. In the same post you suggest raising the flaps at v2plus 10 with all engines operating. I don't know about your type but in the Hawker, VFTO is when the flaps come up in the climb with all engines operating, which is usually about V2plus 30, depending on conditions. We bug V2 as a reference speed in case an engine fails at V1. In that scenario flaps are raised at V2plus 10 in level flight at 1500' while accelerating to VFTO.
AP
AP