Flap retraction
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I fly a G550, and 400 ft flap retraction certainly is in the book, thats not all it says, but on the 2 donks profile 400ft is flap retraction height.
What amazes me more, is that companies override what the manufactures set out as a profile.
What amazes me more, is that companies override what the manufactures set out as a profile.
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Any chance you could send me a page reference?
All I can find in the 550 manual is 06-02-00, normal take off with AT which call for gear then flap before the 400 foot call. I think whats in the 550 manual is correct but not what everyone actually does - never flown a 550 though.
Will try to post the page on here.
All I can find in the 550 manual is 06-02-00, normal take off with AT which call for gear then flap before the 400 foot call. I think whats in the 550 manual is correct but not what everyone actually does - never flown a 550 though.
Will try to post the page on here.
Last edited by tommoutrie; 17th Nov 2012 at 08:29.
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In the FSI document "G550 PTH", on Preface, page MTP-1, Gulfstream has stated that FSI is in fact their training partner, and that documents produced by FSI, are adopted as standard procedure for ALL Gulfstream aircraft.
On Page 19-13 (Rev 5.2, Oct 2011) it states that at 400 Ft AAL, the command "Flaps Up", Flight Level change" shall be given.
If you can get a hold of this document, it provides excellent standards training for pilots new to Gulfstream aircraft, and anyone flying an older generation aircraft where training documents may be lacking.
I'm not here to start a fight gents, just sharing what I got!
Hope this helps
FR
On Page 19-13 (Rev 5.2, Oct 2011) it states that at 400 Ft AAL, the command "Flaps Up", Flight Level change" shall be given.
If you can get a hold of this document, it provides excellent standards training for pilots new to Gulfstream aircraft, and anyone flying an older generation aircraft where training documents may be lacking.
I'm not here to start a fight gents, just sharing what I got!
Hope this helps
FR
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thanks frank - that confirms my earlier suspicion which is that this comes from Flight Safety. Its definitely not whats in the G550 manual from Gulfstream because I've looked at that and tried to post the page. Its not in the Global manual, the Challenger manual, the Embraer Lineage manual, the Cessna Citationjet manual, or the Embraer Phenom manual.
I'm not trying to start a fight either, I'm simply trying to work out why we don't fly these planes the way the manufacturer suggested during a particularly critical phase of flight and why the belief that we should do otherwise is so deeply ingrained. FSI are responsible for teaching a very large number of pilots and there is a commonly held belief that if it comes from them then its gospel. Maybe it isnt..
I'm not trying to start a fight either, I'm simply trying to work out why we don't fly these planes the way the manufacturer suggested during a particularly critical phase of flight and why the belief that we should do otherwise is so deeply ingrained. FSI are responsible for teaching a very large number of pilots and there is a commonly held belief that if it comes from them then its gospel. Maybe it isnt..
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You need to hit the aircraft perf charts, for the CL 30 the acceleration altitude is called the transition segment, section 7-19 of the perf data in the operational reference manual.
I use APG for take off calculations and I was given the option when I opened the account to use 400 or 1500 for this segment. If the airport needs higher than 1500 it is published on the APG data sheet.
What normally happens if I can't do 1500 feet then an emergency turn is published by APG.
I fully agree that the aircraft I fly all wizz through flap retract and careful energy managment is required.
The argument for me waiting for 1500 all engines is that should an engine fail I don't need to remember what the profile should be as I do it all the time.
Never say never though as with a low initial level off after take off or with gusty conditions I use 400 feet and if I am freelancing I do what I am told.
I use APG for take off calculations and I was given the option when I opened the account to use 400 or 1500 for this segment. If the airport needs higher than 1500 it is published on the APG data sheet.
What normally happens if I can't do 1500 feet then an emergency turn is published by APG.
I fully agree that the aircraft I fly all wizz through flap retract and careful energy managment is required.
The argument for me waiting for 1500 all engines is that should an engine fail I don't need to remember what the profile should be as I do it all the time.
Never say never though as with a low initial level off after take off or with gusty conditions I use 400 feet and if I am freelancing I do what I am told.
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Originally Posted by Kak Klaxon
The argument for me waiting for 1500 all engines is that should an engine fail I don't need to remember what the profile should be as I do it all the time.
As for blasting through minimum flap retract or noise abatement - here's an idea - follow procedures - take off in FLC and reduce power after take off. That's what's in every ops manual for every company that I have flown the CJ for and I can count on one hand the number of pilots I know that do it.
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actually, therein lies the problem. You only need to remember a profile to fly at all because of the warped logic coming out of flight safety. The only thing you need to remember (as far as the manufacturers are concerned) is that the flaps on the CJ can come up at V2+10. On the Challenger its V2+20. Phenom its V2+1 and so on. And you always do that whether an engine fails or not. Should you lose an engine before V2+10 (for the CJ and whatever for other aircraft) you will lose a large percentage of your available thrust. You may, therefore, need a level acceleration platform to achieve V2+10 in order to raise the flaps and climb away clean. ICAO introduced two certification platforms - 400 feet and 1500 feet. You will probably remember that the straight CJ happened to be certified at 400 feet but most aircraft now are certified at 1500 feet for a level acceleration platform. The reason was to do with time available at max thrust OEI. In fact, the perversion of leaving the flaps down and climbing at higher speeds against the induced drag causes quite a serious problem - should an engine fail at higher speed when you are still in the take off flap condition, whats your plan? Just consider for a moment where you are - climbing at 160kts against the flap, engine fails at 900 feet (very common for a birdstrike) what do you do?
The reason for taking the flap up at the speed the manufacturer suggests is that is where the L/D curves are closest for the different wing configurations. What you get, therefore, is minimal pitch change, and the most efficient combination of lift and drag for the changing speeds. As soon as you are appreciably over this speed you are simply creating more drag than you need to for the lift you need and there is no case at all for doing this on take off. Its arguable that this is desirable on approach so that you have an element of drag control to help lose speed but on take off all you do is degrade the climb profile and therefore have an associated decrease in safety and increase in noise. Where does it come from?
I think there is quite a serious climb performance gradient issue here which I've done some maths on and there is also an awful lot of confusion caused by poor understanding and incorrect teaching by some of the training organisations (not just flight safety). Pilots talk about different profiles for an all engine operating take off and a loss of thrust condition but in reality they are exactly the same. I just really want to check that I'm not missing something and make sure that no manufacturer issues a manual that tells us to do what everyone is actually doing.
The reason for taking the flap up at the speed the manufacturer suggests is that is where the L/D curves are closest for the different wing configurations. What you get, therefore, is minimal pitch change, and the most efficient combination of lift and drag for the changing speeds. As soon as you are appreciably over this speed you are simply creating more drag than you need to for the lift you need and there is no case at all for doing this on take off. Its arguable that this is desirable on approach so that you have an element of drag control to help lose speed but on take off all you do is degrade the climb profile and therefore have an associated decrease in safety and increase in noise. Where does it come from?
I think there is quite a serious climb performance gradient issue here which I've done some maths on and there is also an awful lot of confusion caused by poor understanding and incorrect teaching by some of the training organisations (not just flight safety). Pilots talk about different profiles for an all engine operating take off and a loss of thrust condition but in reality they are exactly the same. I just really want to check that I'm not missing something and make sure that no manufacturer issues a manual that tells us to do what everyone is actually doing.
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Hi Klaxon, checked and thats all OEI data. Not all engines operating. All that does is add to the fact that you shouldnt be climbing with take off flap at anything significantly above the flap retraction speed otherwise you dont really know where you are along the all engines operating take off path..
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you calculate a single engine net take off path (or more likely a bit of software does it for you) then fly an all engine operating take off and you don't do it the way the manufacturer intended. You hold a take off flap setting, climb against drag, make more noise than necessary, end up in an unknown and unprovable vertical situation with regard to SID gradient, and you use more fuel. And there's no reason for it.
I'll put 100 quid on it. Does that help?
I'll put 100 quid on it. Does that help?
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and its not a boffs question. We all do it wrong, we are pilots, we are taught to do it wrong. And I'm pretty sure I can prove it.
Come on, I'll up the bet if you like. But its two way...
Come on, I'll up the bet if you like. But its two way...
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On the Hawker, we regularly do flap 0 take-offs. The second segment climb performance is calculated using our computerised programme and/or the aircraft manual and is often better than using flap 15 ( not to mention one less action to undertake at a particularly busy stage of the flight).
Some flight departments like to standardise procedures for all types and this could range from a Citation up to an Airbus. Clearly there are different requirements for different aircraft and a one size fits all policy sometimes appears a little non-sensical. Airmanship dictates how we operate and any variations from SOPs are discussed beforehand and need to justifiable to the men in suits at any subsequent board of inquiry.
AP
Some flight departments like to standardise procedures for all types and this could range from a Citation up to an Airbus. Clearly there are different requirements for different aircraft and a one size fits all policy sometimes appears a little non-sensical. Airmanship dictates how we operate and any variations from SOPs are discussed beforehand and need to justifiable to the men in suits at any subsequent board of inquiry.
AP
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AP you are working for the enlightened and thanks for your post. The 125 series aircraft is descended from the Dominie I think which was originally used as an instrument training aircraft by the RAF. When it was used by them it almost always did a flap zero take off because, as you say, its already clean that way and the 2nd segment climb is better. Bizarre then that when its used as a business jet the SOP's get fannied around with and it becomes the norm to take off with flaps set at 15(I think). And then, because the dolt that has written the part B has copied it from someone else, this confusing rubbish about 1500 feet gets thrown into the equation. I advocated taking off in the CJ flap zero at my previous employer and got all sorts of snipes for being experimental.
Nobody want to take the 100 quid bet? I'll up it then to 200. Flight Safety instructors particularly welcome..
Nobody want to take the 100 quid bet? I'll up it then to 200. Flight Safety instructors particularly welcome..
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Tommoutrie
Yes, the modern Hawker 125 series is descended from the Dominie albeit with more powerful fan engines as opposed to the original constant thrust, variable noise Viper turbojets.
There seems to be confusion between second segment and noise abatement climb profiles and what they are trying to achieve. 1500' agl is the end of the second segment climb and is the point at which you will accelerate, retract flap if used, and accelerate to en-route climb speed, having had an engine fail at V1. The calculation allows for the aircraft in this condition, if flown straight ahead at V2 to 1500', to clear all obstacles to that point. If this is not possible then an emergency turn procedure is devised. At least, that is how our performance programme works, and it will give profiles for both flap 15 and flap 0.
Noise abatement profiles assume both engines operating and are designed to leave as much noise in the vicinity of the airport as possible with as much height gained over distance travelled as possible (vx) prior to cleaning up and reducing power to a level sufficient to give an acceptable rate of climb or height in time (vy) with minimum noise nuisance.The goal of a noise abatement climb is to reduce noise whereas the goal of second segment climb is to clear obstacles.
Now consider a standard departure where both engines function correctly. If the performance calculation shows that you could clear all obstacles to1500'agl if the aircraft is flown correctly with an engine out at V1 with flap 0 or flap 15, then all that is required to stay safe with two engines operating is a sufficient rate of climb to satisfy the requirements of the SID. This is generally less than a 5% gradient which is the same as a standard ILS, or 750'pm at 150kts. The best two engine performance for our aircraft is achieved by initially pitching to 12degrees and retracting flap and reducing power at the calculated flap retract speed, which is usually reached by 400'agl. Leaving flap extended beyond that speed will result in unnecessary drag and a performance penalty. I generally accelerate after flap retraction to 180-200kts for the initial turn on the SID and control rate of climb with power to avoid exceeding 1000'pm in the final 1000' to level-off (our SOP). This profile exceeds the obstacle clearance requirements of a standard SID four-fold on an ISA day at sea level with climb power set!
Clearly, all departures are briefed and profiles adjusted to suit conditions, terrain and airport requirements. I can't think of any scenario, however, when it is advantageous to leave flap at take-off setting past calculated flap retract speed on our aircraft with both engines operating.
Sorry for the ramble, I really haven't been drinking!
AP
Yes, the modern Hawker 125 series is descended from the Dominie albeit with more powerful fan engines as opposed to the original constant thrust, variable noise Viper turbojets.
There seems to be confusion between second segment and noise abatement climb profiles and what they are trying to achieve. 1500' agl is the end of the second segment climb and is the point at which you will accelerate, retract flap if used, and accelerate to en-route climb speed, having had an engine fail at V1. The calculation allows for the aircraft in this condition, if flown straight ahead at V2 to 1500', to clear all obstacles to that point. If this is not possible then an emergency turn procedure is devised. At least, that is how our performance programme works, and it will give profiles for both flap 15 and flap 0.
Noise abatement profiles assume both engines operating and are designed to leave as much noise in the vicinity of the airport as possible with as much height gained over distance travelled as possible (vx) prior to cleaning up and reducing power to a level sufficient to give an acceptable rate of climb or height in time (vy) with minimum noise nuisance.The goal of a noise abatement climb is to reduce noise whereas the goal of second segment climb is to clear obstacles.
Now consider a standard departure where both engines function correctly. If the performance calculation shows that you could clear all obstacles to1500'agl if the aircraft is flown correctly with an engine out at V1 with flap 0 or flap 15, then all that is required to stay safe with two engines operating is a sufficient rate of climb to satisfy the requirements of the SID. This is generally less than a 5% gradient which is the same as a standard ILS, or 750'pm at 150kts. The best two engine performance for our aircraft is achieved by initially pitching to 12degrees and retracting flap and reducing power at the calculated flap retract speed, which is usually reached by 400'agl. Leaving flap extended beyond that speed will result in unnecessary drag and a performance penalty. I generally accelerate after flap retraction to 180-200kts for the initial turn on the SID and control rate of climb with power to avoid exceeding 1000'pm in the final 1000' to level-off (our SOP). This profile exceeds the obstacle clearance requirements of a standard SID four-fold on an ISA day at sea level with climb power set!
Clearly, all departures are briefed and profiles adjusted to suit conditions, terrain and airport requirements. I can't think of any scenario, however, when it is advantageous to leave flap at take-off setting past calculated flap retract speed on our aircraft with both engines operating.
Sorry for the ramble, I really haven't been drinking!
AP
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That sounds absolutely spot on. I think you are in a tiny minority of operators who are doing it right. Genius! Hey at least that confirms I'm not completely nuts!
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The CAE Manual for the G4 states "At VFS (Minimum), select FLCH" so this would have you retract the flaps based on a speed rather than a height.
But of course that's not the way we do it
The 400 feet froms from aircraft certification where the limits are between 400-1200 feet, the 1500/3000 feet comes from ICAO noise abatement. They were not developed to meet the same goals, in the same sense as the certified gradient will not protect you for the SID departure gradient requirements.
Mutt
But of course that's not the way we do it
The 400 feet froms from aircraft certification where the limits are between 400-1200 feet, the 1500/3000 feet comes from ICAO noise abatement. They were not developed to meet the same goals, in the same sense as the certified gradient will not protect you for the SID departure gradient requirements.
Mutt
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aarrgh!! More evidence from the manufacturer! Why don't we do it like they want us to?
The ICAO level acceleration platforms are 400 to 1500 feet - they are in document 8168. In fact you can choose to certify your plane using any level acceleration platform between and including those two heights but all of that is to do with OEI operation.
NAP1 and NAP2 are noise abatement procedures for close in and slightly further away noise reduction. These are applicable to all engine operating conditions and almost all biz jet operators ignore them deciding that the body angles achieved are too great (there's a body angle max suggestion of 20 degrees). What most operator choose to do is leave the flaps down and accelerate anyway which degrades the take off path and actually causes more noise.
All of this is supporting my argument.
Tell you what... I'm upping the bet to a grand...
The ICAO level acceleration platforms are 400 to 1500 feet - they are in document 8168. In fact you can choose to certify your plane using any level acceleration platform between and including those two heights but all of that is to do with OEI operation.
NAP1 and NAP2 are noise abatement procedures for close in and slightly further away noise reduction. These are applicable to all engine operating conditions and almost all biz jet operators ignore them deciding that the body angles achieved are too great (there's a body angle max suggestion of 20 degrees). What most operator choose to do is leave the flaps down and accelerate anyway which degrades the take off path and actually causes more noise.
All of this is supporting my argument.
Tell you what... I'm upping the bet to a grand...