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Flaps on take off

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Old 30th March 2013 | 15:59
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Flaps on take off

Question for the Pro pilots /engineers.

Do nodern aircraft systems merely indicate to the crew an incorrect configuration or would they actually block the roll.? I was reading of the NW accident where it was suggested that the crew had deployed a circuit breaker and that this had resulted in the warning being missed and take off continuing with an incorrect setting.

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Old 30th March 2013 | 16:43
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From: Planet Claire
In the Embraer 145 series you press the 'T/O Config' button and she says 'Takeoff OK' if you're configured.

If you forgot, say, the flaps -she says 'Take off FLAPS'

Very safe system.

On some a/c you press the button and get silence if you are correctly configured. You also get silence if the T/O config system is u/s, which is what happened to the MD at MAD. Not as safe, but still very common.

Last edited by AtomKraft; 30th March 2013 at 16:44.
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Old 30th March 2013 | 17:28
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Thanks for your response.

If you ignored the warning would it still allow you to roll?
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Old 30th March 2013 | 18:59
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I would guess all take-off configuration warning systems are purposely designed in a way they can be overridden, simply because there are some phases of flight where a false warning might be even dangerous. These situations include the take-off run past V1, i.e. the speed above which the take-off must not be aborted even in case of malfunctions, such as an engine failure or fire, or touch-and-go landings.

Last edited by hvogt; 30th March 2013 at 18:59.
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Old 30th March 2013 | 19:20
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From: Planet Claire
KLOS

Nothing can stop you from rolling, but why would you if not configured?

Trying to get airborne flapless, for example, will kill you.
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Old 30th March 2013 | 19:54
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From: luton
FFS klos why would any crew ignore a T/O config warning????

Last edited by walterthesofty; 30th March 2013 at 19:55.
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Old 30th March 2013 | 20:47
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From: fort sheridan, il
Dear original Poster

Yes, you can attempt to takeoff without flaps...the warning system is just that, a warning ...it won't apply the brakes or shutdown the engines.

You could easily attempt to takeoff with the warning horn blaring. You could "ROLL"...

Your questions was quite understandable and should have been answered: YES YOU CAN ROLL FOR TAKEOFF EVEN IF THE WARNING SYSTEM IS TELLING YOU THE FLAPS ARE NOT CORRECT (or other "configuration problems) .

There is no plane to my knowledge (38 years) that would physically prevent you from taking off with a warning of flaps incorrect.

Do be advised that there are some planes (not many) that takeoff without flaps extended. The Fokker F100 comes to mind.

The Detroit crash was a very tragic one. I flew the same series of planes for many years...and the first thing I did upon entering the cockpit (assuming power on) was to advance the throttles and hear the warning...even before I checked for the circuit breaker position. No warning..check CB and write it up (for maintenance to examine).

Many pilots use "muscle memory" and force their hand to touch the 'flap' handle and make sure it is properly set for takeoff...and we do it just before we attempt to takeoff.

good luck and happy landings
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Old 30th March 2013 | 21:20
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SSR

Many thanks, as very, for your most helpful response. I know YOU understand that I was NOT suggesting that it should be be overridden but it could be. A pilot might want to commit suicids or simply become incapacitated. To those that don't understand,--- why do Airbus build in a stall inhibit-?no pilot would ignore stall warning would they? BEA Trident London 1970 - three man crew plus positioning pilot in jump seat. stall warning overridden- deep stall irrecoverable.

Thanks again for taking the trouble
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Old 30th March 2013 | 21:23
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HVOGT

Many thanks also for your helpful and polite reponse
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Old 30th March 2013 | 21:32
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From: Jeddah
Why do the Takeoff Alternate should be one hour for twin engine jet

Can someone tell me why Takeoff Alternate airport should be one hour for the Two Engine aeroplane when etop requirement for the certain aeroplanes is now FAA certified to be more than 60 minutes
PART 121 IFR OPERATIONS
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Old 30th March 2013 | 21:38
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From: Bloody Hell
BEA Trident London 1970 - three man crew plus positioning pilot in jump seat. stall warning overridden- deep stall irrecoverable.
Oh that's a whole new story, read Blind Pew's post's especially his book, gives you a whole new perspective.

Last edited by FLCH; 30th March 2013 at 21:38.
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Old 30th March 2013 | 22:40
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FCLH

Thanks- where can I find it? Grateful for info/ John Collins was a friemd of my family. There has been suggestion that he from the jump seat did try to do something to save the day.

I meant to add - Or a SFO on a B767 would not push down when the Captain was screaming to pull up from dive into the cean- nah
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Old 30th March 2013 | 22:59
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Takeoff Warning Throttle burst as you take the runway or preferably as you are taxing to the runway but not with the parking brake set, that should cover it. If you hear the warning something is not right. That warning horn covers multiple things.
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Old 31st March 2013 | 10:26
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From: luton
"A pilot might want to commit suicide".. now that's is a factor I bet they never considered ...it's about time they started building aircraft that were more suicide resistant...you never know flapless take off suicides may become the method of choice in the future

Last edited by walterthesofty; 31st March 2013 at 10:27.
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Old 1st April 2013 | 05:28
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Dear WTS.

Let me try again as you seem to be having some difficulty .

The NW at Michigan ( there have been others AA and Delta) took off with an incorrect flap setting. To repeat your question ( rhetorical?) without the gratuitously offensive acronym- why would they do it? I don't kmow. I assume it was inadvertent, but they did. My sole point is that- would it not be better for everyone if aircraft were designed to inhibit roll where the flaps are incorrectly set as with my car which will not start unless it is in neutral. SSR ( the professional pilot) has understood and replied politely.
Best Wishes
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Old 1st April 2013 | 13:00
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KLOS, there are many occasions when an aircraft may be flown using a non-standard `configuration`; frinstance,a flap or slat problem ,and the aircraft is at an airport that has inadequate/no engineering facilities.The crew get permission from their operating authority/Aviation Authority/Manufacturer,if necessary, to ferry the aircraft in that condition,having worked out the necessary performance for take-off/landing/diversion.Obviously passengers would not be carried...happens every day...
If your car won`t start correctly,what do you do..? call the garage,mech comes to fix..if not it`s towed away..
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Old 1st April 2013 | 13:10
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From: Down Sarf
And that dear OP is it in a nutshell.
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Old 1st April 2013 | 16:08
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KLOS

My first reply to your question was based on a brief look at the relevant certification specifications for take-off configuration warning systems. I put the word 'guess' in italics, because I know nothing more about such systems than what is (was) required for obtaining a professional pilot licence. I must admit that, since the question was posted in 'Spectators Balcony', I thought a rather short reply would do. I hope you will forgive my arrogance.

On our side of the Atlantic, the systems in question are certified under the Certification Specifications for Large Aeroplanes (CS-25) of the European Aviation Safety Agency (EASA). The Agency has published acceptable means of compliance (AMC) along with the specifications. It was from a brief look at these AMCs that I saw the problem of unwanted or nuisance warnings is an important design aspect.

A design which would be capable of physically inhibiting the take-off roll might have prevented some of the accidents already mentioned in this thread. On the other hand, any system that could prevent an aircraft with running engines from rolling could prove fatal in case of a malfunction. To pick up the analogy to your car, what would happen if the system which blocks the ignition when the gear lever is not in neutral had a malfunction and would engage while you were overtaking on a motorway? Nothing you couldn't handle; you'd just switch on the warning lights and bring the car to a stop. Now, what would happen if the malfunctioning take-off configuration warning system of an aircraft would engage during the take-off run, shortly before the aircraft has reached a speed where it could safely take-off but is already too fast to stop within the length of the remaining runway? Obviously, the outcome would be rather embarrassing.

Again, I must emphasise I have no background in aircraft design or engineering and probably someone with a deeper understanding of system design will find good reasons for allowing a warning system to inhibit an attempted take-off roll.

Last edited by hvogt; 1st April 2013 at 16:10.
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Old 1st April 2013 | 17:35
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HVOGT,

Many thanks for your helpful and polite response. I saw no arrogance in your original post. It would indeed be instructive to know whether such an inhibit has been mooted and rejected for the reasons you posit

KInd regards
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Old 1st April 2013 | 17:39
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sycamore and spot,

Thanks for your replies
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