flaps30
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Technical Question About Cockpit In General

Mon May 25, 2009 5:40 pm

I know in the past there have been some airline crashes due to the flaps not being deployed for takeoff. Northwest MD-80 in Detroit, LH 747 in Nairobi, and possibly Spanair in Madrid last year come to mind. My question is, is there any kind of alarm in the cockpit to alert the pilot that the flaps are not deployed before he/she tries to apply full thrust for takeoff. Besides a pre-takeoff checklist, what other measures are there to assure this does not happen.
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metroliner
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RE: Technical Question About Cockpit In General

Mon May 25, 2009 5:52 pm

There can be a take-off configuration warning which sounds if certain parameters are insatisfactory for takeoff. Some I've seen include the trim being out of range for take-off and the flaps not being set. But I'm sore someone with more technical knowledge will chime in with specifics to the incidents you mention  Smile

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EMBQA
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RE: Technical Question About Cockpit In General

Mon May 25, 2009 7:54 pm



Quoting Metroliner (Reply 1):
But I'm sore someone with more technical knowledge will chime in with specifics to the incidents you mention

You are indeed correct. I think teh requirment came from the Northwest MD-80 crash.....
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josekmlb
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RE: Technical Question About Cockpit In General

Mon May 25, 2009 11:20 pm

Her name is Bitching Betty in the MD-88 and I think she says FLAP FLAP or something like that. When you talk about the flaps for takeoff the one that comes to mind is a 727 for DL in DFW that crashed forgot to put the slats/flaps down for T/O. But yes there is an alarm in the cockpit for flap settings.
 
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Jetlagged
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RE: Technical Question About Cockpit In General

Tue May 26, 2009 12:01 am

Most aircraft have a take-off config warning alarm which sounds if the throttles are advanced with one or more item out of configuration. This will include LE and TE devices. The 747 has a horn which warns if, amongst other things, the LE flaps are not deployed or the TE flaps are out of take-off range. The LE warnings were added as a result of the Nairobi crash.
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tb727
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RE: Technical Question About Cockpit In General

Tue May 26, 2009 12:01 am



Quoting EMBQA (Reply 2):

You are indeed correct. I think teh requirment came from the Northwest MD-80 crash.....

The system was there, it was just not working. No warning horn sounded, possibly because the CB had popped for the system, although it was never determined if that was the reason. I would imagine that is what had happened though.

The plane I fly is certified for 0 flap takeoffs so we do not get a horn. All we get a horn for is for out of trim takeoff and a big red light if the airbrakes are extended with flaps extended and power above 88% or so.
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Viscount724
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RE: Technical Question About Cockpit In General

Tue May 26, 2009 1:26 am



Quoting EMBQA (Reply 2):
Quoting Metroliner (Reply 1):
But I'm sore someone with more technical knowledge will chime in with specifics to the incidents you mention

You are indeed correct. I think the requirment came from the Northwest MD-80 crash.....

Although, if memory correct, the MD-80 had a warning system at the time of both the NW and Spanair crashes, but for whatever reasons it didn't work.
 
PGNCS
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RE: Technical Question About Cockpit In General

Tue May 26, 2009 4:00 am



Quoting EMBQA (Reply 2):
Quoting Metroliner (Reply 1):
But I'm sore someone with more technical knowledge will chime in with specifics to the incidents you mention

You are indeed correct. I think teh requirment came from the Northwest MD-80 crash.....

The system was there prior to the accident in DTW; it did not fucntion correctly for reasons that were never discovered.

Quoting JoseKMLB (Reply 3):
When you talk about the flaps for takeoff the one that comes to mind is a 727 for DL in DFW that crashed forgot to put the slats/flaps down for T/O. But yes there is an alarm in the cockpit for flap settings.

The warning was there was on the 727; the warning failed to work.

Quoting Viscount724 (Reply 6):
Although, if memory correct, the MD-80 had a warning system at the time of both the NW and Spanair crashes, but for whatever reasons it didn't work.

You are correct. Configuration warnings vary in their specifics, but like anything else they can fail. If they fail at the same time the crew has a breakdown in procedural discipline, the setup is in place for an accident.
 
flaps30
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RE: Technical Question About Cockpit In General

Tue May 26, 2009 4:34 am



Quoting Viscount724 (Reply 6):
but for whatever reasons it didn't work.

I will say that is not very comforting. I know they are machines and not perfect, but to know that these critical systems can fail for unknown reasons at the absolute worst time, makes me wonder why there are no back-up systems in place in case the first one fails ( I am speaking only of the warning system for the flap setting).
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FlyASAGuy2005
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RE: Technical Question About Cockpit In General

Tue May 26, 2009 4:50 am

I get what you're saying but the warning is the redundant system I believe. The first line of defense is the pilots themselves and their checklists. Now, like you said, if there is a failure of the system just at that unfortunate time when something is forgotten or overlooked then...
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Starlionblue
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RE: Technical Question About Cockpit In General

Tue May 26, 2009 7:22 am

As FlyASAGuy2005 says, the warning is the redundant system. There is always a small risk, but quite frankly with two pilots, a checklist and a warning system it was only through a very unlikely occurrence that this rather important item slipped past the routine.

Not saying it isn't tragic, just that it's hard to think of every possible possibility.
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PGNCS
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RE: Technical Question About Cockpit In General

Tue May 26, 2009 6:05 pm



Quoting Flaps30 (Reply 8):
I will say that is not very comforting. I know they are machines and not perfect, but to know that these critical systems can fail for unknown reasons at the absolute worst time, makes me wonder why there are no back-up systems in place in case the first one fails ( I am speaking only of the warning system for the flap setting).

Like others have said, the pilots using a checklist are the primary system to prevent incorrectly configured takeoffs. The CAWS is the redundant system.
 
stratosphere
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RE: Technical Question About Cockpit In General

Tue May 26, 2009 7:37 pm



Quoting PGNCS (Reply 7):
The warning was there was on the 727; the warning failed to work.

Yep and after that crash the takeoff warning system is checked pretty regularly on the 727 atleast here at FedEx it is and it requires atleast 2 mechanics to test it one in the electronics bay and one in the cockpit.
 
pilotpip
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RE: Technical Question About Cockpit In General

Wed May 27, 2009 5:01 am

Ok, this only goes for the EMB-145 and ERJ-170.

Specifically the 170. It's been too long for the 145 but I recall it being the same. Both aircraft have a "takeoff config" button on the center pedestal. We push this as part of our before takeoff flow. It will give an aural warning of "Takeoff O/K" if we're good to go. It will say "No takeoff Flaps/Brakes/Trim" for any of the mentioned items. In addition, if the flaps aren't at a takeoff setting (1,2 or 4) and the above criteria isn't met with the brakes and trim it will give the same warning when the thrust lever angle goes above a certain setting. When kids come up to take a look at the cockpit I usually "make the plane talk" for them by doing one of these things or having the kid push the thrust lever up far enough. They either get a kick out of it or it scares the crap out of them.  Smile

In addition to this, in our flow after pushing out is to set flaps and make sure the trim is set. This is SOP at most airlines which is why you see them taxi out with flaps extended. We verify the flap, trim and thrust setting as well as V speeds during our after start checklist.
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Starlionblue
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RE: Technical Question About Cockpit In General

Wed May 27, 2009 5:31 am



Quoting Pilotpip (Reply 13):
We push this as part of our before takeoff flow. It will give an aural warning of "Takeoff O/K" if we're good to go. It will say "No takeoff Flaps/Brakes/Trim" for any of the mentioned items

That's pretty clever. So I guess if the thing warning system isn't working it will tell you that (or be quiet). Nice way to know that's working. Of course if you don't press it... But as I said before you can't protect against absolutely everything.
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HAWK21M
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RE: Technical Question About Cockpit In General

Wed May 27, 2009 8:58 am



Quoting Flaps30 (Thread starter):
My question is, is there any kind of alarm in the cockpit to alert the pilot that the flaps are not deployed before he/she tries to apply full thrust for takeoff.

The B737/757s have a T/O configuration warning system in place.Which gives an alert if the configuration of the aircraft is not satisfactory for take off.Normally considers the Spoilers retracted,Flaps in T/O range,Stablizer in green band,parking brake released,when thrust levers moved forward,all of the above should be satisfied.

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David L
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RE: Technical Question About Cockpit In General

Wed May 27, 2009 10:44 am



Quoting Starlionblue (Reply 14):
Quoting Pilotpip (Reply 13):
We push this as part of our before takeoff flow. It will give an aural warning of "Takeoff O/K" if we're good to go. It will say "No takeoff Flaps/Brakes/Trim" for any of the mentioned items

That's pretty clever. So I guess if the thing warning system isn't working it will tell you that (or be quiet). Nice way to know that's working.

There's something similar in the FBW Airbuses:


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The T.O. CONFIG button is directly below the AIR DATA rotary switch at the top, centre of the pedestal.
 
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Jetlagged
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RE: Technical Question About Cockpit In General

Wed May 27, 2009 1:37 pm



Quoting David L (Reply 16):
There's something similar in the FBW Airbuses:

The T.O. CONFIG button is directly below the AIR DATA rotary switch at the top, centre of the pedestal.

Not only that but ECAM shows the Takeoff configuration items and as each item gets set the line goes green. When everything is correctly set it prompts the crew to press the T.O CONFIG button to verify and that line goes green too. The only takeoff check then becomes "all green".

The Fokker 100/70 has a similar T.O. Config test pushbutton. It simulates the advance of the power levers and triggers an aural warning if anything is not correctly set, although in test mode the parking brake is ignored. Very advanced jet for it's time, that Fokker.  Wink
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David L
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RE: Technical Question About Cockpit In General

Wed May 27, 2009 6:56 pm



Quoting Jetlagged (Reply 17):
Not only that but ECAM shows the Takeoff configuration items and as each item gets set the line goes green. When everything is correctly set it prompts the crew to press the T.O CONFIG button to verify and that line goes green too. The only takeoff check then becomes "all green".

Yes but if I'd mentioned it there was the danger that someone might ask which items are checked. All I can remember are:

Flaps - Appropriate for take-off
Spoilers - Armed
Autobrake - Max

I'm sure there's more.

Quoting Jetlagged (Reply 17):
Very advanced jet for it's time, that Fokker.

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Airbus fans.  biggrin 
 
pilotpip
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RE: Technical Question About Cockpit In General

Wed May 27, 2009 10:12 pm



Quoting Starlionblue (Reply 14):
That's pretty clever. So I guess if the thing warning system isn't working it will tell you that (or be quiet). Nice way to know that's working. Of course if you don't press it... But as I said before you can't protect against absolutely everything.

I don't know if it can be deferred. However it's part of my flow as we cross the hold short line to press it. It's a mentioned item in the before takeoff checklist. That's the third crosscheck of the configuration. The first two being done by the two of us up front on the after start checklist before we even roll away from the gate.
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