Selecting flaps during turns
Nemo Me Impune Lacessit
Join Date: Jun 2004
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Thank you ZeBedie, I do remember the BAC1-11 didn't have LE devices but everything after that did so I included them as high lift devices that, if they ran asymmetrically, during a turn, could also spoil your day.
From memory - the American Airlines Upset Recovery video recounts the introduction of the 757 and a check on the inboard flap asymmetry case (in the Sim) with eye-watering results!
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I did come across a training captain from a neighbour airline whose personal opinion was to teach not setting the park brake when 'line up & wait' on the runway. Why? The brakes might stick on and you block the runway. Like I said the list could be endless if you let your imagination go wild.
To be certified under Part 23 the aircraft must still be controllable following failure of one primary control system. eg be able to control roll with rudder if ailerons fail, attitude with trim if elevator fails etc.
In testing a type that I fly, they had to test fly with one flap at zero and one at 30% and still be able to control roll with aileron, which the aeroplane easily did or it wouldn't have been certified.
So I call bull**** on the "never put flap down in a turn" theory, unless it is in the limitations section of the POH and I've never seen it there in any of the types I fly.
In testing a type that I fly, they had to test fly with one flap at zero and one at 30% and still be able to control roll with aileron, which the aeroplane easily did or it wouldn't have been certified.
So I call bull**** on the "never put flap down in a turn" theory, unless it is in the limitations section of the POH and I've never seen it there in any of the types I fly.
Years ago I flew with a chap who wouldn’t
use more than 20 degrees of bank (B727)
in any mode of flight
I asked him why and he informed me when you did this the aircraft would ‘disappear on radar’
He was stealthy ahead of his time..
use more than 20 degrees of bank (B727)
in any mode of flight
I asked him why and he informed me when you did this the aircraft would ‘disappear on radar’
He was stealthy ahead of his time..
Interestingly I was informed just the other day by a former military pilot that not setting the park brake at the holding point or when lined up on the runway was SOP at RAAF Central Flying School a few years ago. . The reason given was a single instance where a pilot overseas was lined up with park brake on awaiting take off clearance when he realised another aircraft was on very short final and intent on landing. The pilot on the runway gunned the throttle to clear the runway but in his haste forgot the park brake was on. The crash was inevitable. A statistically improbable event and certainly no reason to not have the park brake on whenever an aircraft is stationary anywhere.
I've certainly not come across this in 30 years of Mil and Civ flying but think the inability to change flap settings in a turn (ie change speed in a turn) would severely limit one's ability to operate freely and flexibly in a busy air traffic environment.
Almost all modern transport aircraft have some form of asymmetric flap protection which would render this technique rather pointless anyway.
Almost all modern transport aircraft have some form of asymmetric flap protection which would render this technique rather pointless anyway.
Why is there a constant need to over complicate everything?
A turn has no bearing on flap extension or retraction.
Speed and the relationship to angle of attack and minimum speeds, of course, is very relevant. If you are too slow to retract flaps in the turn, then you are too slow. Period. Either speed up or wait. If you have adequate energy, margin, and speed, extend or retract in the turn.
Flap assymetry is flap assymetry, whether in the turn or not.
The aircraft doesn't know if it's in a turn or how high it is; flaps extended or retracted in a turn or 3 feet above the ground ..... it doesn't know or care where or when. It can't think, it can't see and last it knew, it was perfectly happy and content two seconds before you flew it into the side of a mountain.
Raising or extending flaps is perfectly safe in a turn, if you do it properly. Raising the flaps at 5 feet above the ground is perfectly safe, if done properly.
It should be done sensibly, just like anything else in an aircraft.
Your welcome...
A turn has no bearing on flap extension or retraction.
Speed and the relationship to angle of attack and minimum speeds, of course, is very relevant. If you are too slow to retract flaps in the turn, then you are too slow. Period. Either speed up or wait. If you have adequate energy, margin, and speed, extend or retract in the turn.
Flap assymetry is flap assymetry, whether in the turn or not.
The aircraft doesn't know if it's in a turn or how high it is; flaps extended or retracted in a turn or 3 feet above the ground ..... it doesn't know or care where or when. It can't think, it can't see and last it knew, it was perfectly happy and content two seconds before you flew it into the side of a mountain.
Raising or extending flaps is perfectly safe in a turn, if you do it properly. Raising the flaps at 5 feet above the ground is perfectly safe, if done properly.
It should be done sensibly, just like anything else in an aircraft.
Your welcome...
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Flap assymetry is flap assymetry, whether in the turn or not
In the 1970s we were not permitted to alter flap settings in the Viscount whilst turning. We were told that the aeroplane had previous form with assym flap.
I remember that very well because, flying a tight arrival the voice from the LHS announced "I hope you aren't planning to extend flap in the turn, Basil, because you know it isn't allowed!" Bas had forgotten that The Boss was commanding that sector.
I remember that very well because, flying a tight arrival the voice from the LHS announced "I hope you aren't planning to extend flap in the turn, Basil, because you know it isn't allowed!" Bas had forgotten that The Boss was commanding that sector.
Moving Target Indicator looks at the radial speed of the target and, if it is zero, assumes that it is a ground return and does not paint so, at the precise moment a passing target is tangential to the radar head, it will not paint on the PPI screen.
I guess, if you flew a perfect circle around the radar aerial, you wouldn't paint.
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I hope no eager beaver CP's are reading this and think their SOP's need a revamp and tweaking update. There could be an endless list of things that people could dream up where they fall into the category of 'I wouldn't do that just incase something else goes wrong.'
I did come across a training captain from a neighbour airline whose personal opinion was to teach not setting the park brake when 'line up & wait' on the runway. Why? The brakes might stick on and you block the runway. Like I said the list could be endless if you let your imagination go wild.
I did come across a training captain from a neighbour airline whose personal opinion was to teach not setting the park brake when 'line up & wait' on the runway. Why? The brakes might stick on and you block the runway. Like I said the list could be endless if you let your imagination go wild.
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if you're worried about that every time you're in a turn, you may be overthinking it a bit.
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Looking at the myriad of posts providing reasons for not applying flaps in a turn. To put this in perspective, all of these reasons such as stall, asymmetric operation, etc, would not all of those conditions be an issue at any point below 500 feet? (forget about turns)
Part 23 -- Airworthiness Standards: Normal, Utility, Acrobatic, and Commuter Category Airplanes
Mechanical interconnection requirement of Sec. 23.701(a)(1). This requirement is to ensure against hazardous asymmetrical operation of the flaps after any probable single or probable combination of failures of the flap actuating system. A probable combination of failures should be considered when the first failure would not be detected during normal operation of the system, including periodic checks, or when the first failure would inevitably lead to other failures. (Systems where a probable combination of failures may occur could include the electrical and hydraulic systems.) The airplane must also be shown to be capable of continued safe flight and landing without requiring exceptional pilot skill or strength following these failures. To demonstrate that the airplane is safe under these conditions, tests should be conducted with the flaps being retracted on one side and extended on the other during takeoffs, approaches, and landing. If there is a probable hazardous condition, a separate positive connection that is not part of the flap actuation system is required.
Part 23 -- Airworthiness Standards: Normal, Utility, Acrobatic, and Commuter Category Airplanes
Mechanical interconnection requirement of Sec. 23.701(a)(1). This requirement is to ensure against hazardous asymmetrical operation of the flaps after any probable single or probable combination of failures of the flap actuating system. A probable combination of failures should be considered when the first failure would not be detected during normal operation of the system, including periodic checks, or when the first failure would inevitably lead to other failures. (Systems where a probable combination of failures may occur could include the electrical and hydraulic systems.) The airplane must also be shown to be capable of continued safe flight and landing without requiring exceptional pilot skill or strength following these failures. To demonstrate that the airplane is safe under these conditions, tests should be conducted with the flaps being retracted on one side and extended on the other during takeoffs, approaches, and landing. If there is a probable hazardous condition, a separate positive connection that is not part of the flap actuation system is required.
The airplane must also be shown to be capable of continued safe flight and landing without requiring exceptional pilot skill
FAA DOT regulations: "Be able to maintain any required flight condition and make a smooth transition from any flight condition to any other flight condition without exceptional piloting skill, alertness, or strength, and without danger of exceeding the limit load factor under any operating condition probable for the type."
The A320 has automatic brakes which will immediately lock the flaps in the event of asymmetric deployment.
The A320 has automatic brakes which will immediately lock the flaps in the event of asymmetric deployment.
Yes, and if it trips, it will remove power to the devices, stopping them (only the symmetric panels) wherever they happen to be. Whilst it is a great idea, it puts another failure level into the system, as a problem with the symmetry protection can itself stop parts of the system from operating....so the flaps themselves might be fine, but the protections system isn't. That's a pretty benign failure though and a rare one.
The reality is that modern jets are every bit as easy to crash as were the older ones.
The reality is that modern jets are every bit as easy to crash as were the older ones.
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Split flap protection.
I was in the back seat of an L1011 simulator when the sim pilot failed the asymmetry protection in flight on final. I glimpsed a blink on the annunciator panel but before I could focus on that we were rolling after the captain called for the next notch of flaps. Full opposite wheel did not help as we crashed and burned. My takes: the most important pre flight check on that bird was the annunciator panel light check, if something crazy happens undo the last thing you were doing. If the sim aero was correct full wheel could not correct the asymmetry. Maybe additional rudder would have. This is only in regard to aircraft asymmetry certification requirements. I will change flap settings in a turn.