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B737 - forgetting to set take off flap?

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B737 - forgetting to set take off flap?

Old 18th Oct 2006, 11:51
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B737 - forgetting to set take off flap?

Since Boeing revised the B737 checklist policy about one year ago (?) to reduce the number of items to be actioned while taxiing for take off to just one item - FLAPS - there have been reports filtering quietly through the system of crews forgetting to select flaps for take off. Fortunately this has been picked up by the take off warning configuration as the thrust levers are opened at the start of the take off run.

These are not rumours but facts in Australia. It is a good bet that there have been many more instances of this happening and I was wondering if any Pprune readers have run into the same problem and under what circumstances.

I wonder if this is a new problem (forgetting take off flap until config warnings says "Oops!") and if so, could it have something to do with the Boeing revised checklist policy?

Previously the Before Take Off Checklist included items such as flight controls...Free, stab trim...set, Recall...check, and so on. Crews got used to the flow of words and if one line was missed out by the checklist reader, an astute other pilot would immediately twig a line was missed.

But now with most items completed and checklists read before push-back or before taxiing, leaving the Before Take Off checklist to just - FLAPS - ...it is easy to miss that one drill especially while busy taxiing. How many readers are game enough to admit to forgetting to set the flaps and have been only caught by the sound of the configuration warning?
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Old 19th Oct 2006, 02:31
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Not totally relevant perhaps but I was pax on a Vasp feeder flight GIG/GRU in a 200 where no flaps were selected on takeoff and where I suspected then it was on purpose. Aircraft half full, undercarriage didn't collapse despite the terrific jarring and we got off after a loong roll. Only thoughts were I'd hate to look at the undercarriage afterwards.
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Old 19th Oct 2006, 04:29
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A recent ASRS report submission (Aviation Safety Reporting System) published an incident where the crew did just this - takeoff with flaps retracted in a 737NG.

Here is the link to the ASRS page:
http://asrs.arc.nasa.gov/callback_issues/cb_320.htm

Here is a cut and paste of the report...

This B737-800 flight crew was interrupted twice while running pre-departure checklists, and a cockpit warning device that could have alerted them to the aircraft’s unsafe configuration, failed to function.

* …We performed the After Start checklist and the First Officer called for taxi. As we started the taxi, I called for the Taxi checklist, but immediately became confused about the route and queried the First Officer to help me clear up the discrepancy. We discussed the route and continued the taxi...We were cleared for takeoff [on] Runway 01, but the Flight Attendant call chime wasn’t working. I had called for the Before Takeoff checklist, but this was interrupted by the communications glitch. After affirming the Flight Attendants [were] ready, we verbally confirmed the Before Takeoff checklist complete. On takeoff, rotation and liftoff were sluggish. At 100-150 feet as I continued to rotate, we got the stick shaker. The First Officer noticed the no-flap condition and placed the flaps to 5 degrees. The rest of the flight was uneventful. We wrote up the takeoff warning horn but found the circuit breaker popped at the gate.

The cause of this potentially dangerous situation was a breakdown in checklist discipline attributable to cockpit distraction. The Taxi checklist was interrupted by my taxi route confusion. The Before Takeoff checklist was interrupted by a Flight Attendant communication problem. And for some reason, the takeoff warning horn circuit breaker popped, removing the last check on this sort of thing…From now on, if I am interrupted while performing a checklist, I intend to do the whole thing over again.

Another procedure used by many pilots is to stop (hold) the checklist at the item where an interruption takes place; when the checklist resumes, repeat the last completed item and continue with the rest of the checklist.

<<<<<<<<<<<<<<<<<<<<<

One notable incident similar to this one resulted in a crash during the late 80's at DFW; a Delta 727-200 (happened right after the Delta L-1011 wisdshear crash in DFW). The crew forgot to set the flaps, botched the checklist, stalled and crashed after liftoff killing most of the occupants on board.

I would hazard to guess the more powerful thrust to weight ratio on the NG and the generous wing area, among other probable lucky details, resulted in a routine safety inquiry rather than fatalities as above.

Last edited by DC-Mainliner; 19th Oct 2006 at 05:49.
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Old 25th Oct 2006, 19:55
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Thumbs up

In RYR we use the control column before T/O checklist and it certainly includes flaps, and is very explicitly phrased/ checked in our response to the F/O's challenge "flaps". Don't know how you guys are doing it down under. I have always found the only sure-fire way not to forget it, and avoid not being able to give a satisfactory reply, is to ALWAYS call for the flap required as soon as taxi-ing is commenced, the only exception being winter-ops with considerable taxi-way contamination.Even at my advanced years this works for me, and if I don't do this, due to some distraction at exactly the wrong moment, yes , more often than not I forget , and am saved by the checklist, or the bright young chap/ chapess alongside me.
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Old 17th Oct 2007, 20:59
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Question Incorrect Flaps

I was interested in your post and was wondering if it is only the B737 or are the other boeing aircraft involved as well i.e. the B767 and B747 and do you have any idea how many instances rougly in 12 months. Also were they related to the checklists or changes of runway or other issues? Were they saved by the config warnings or did they realise before T/O?
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Old 17th Oct 2007, 21:34
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Airbus policy is to set them during the after starts which seemed a bit odd at first after the 737 but it has some advantages. Trims and flaps are both set after start and the aircraft is in a flyable configuration before it starts to move.
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Old 17th Oct 2007, 22:22
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We dont use boeing procedures so far but ours are of course influenced by them. For several years now we select flaps first before we do the after start checklist (actually start checklist below the line) and is checked during the same checklist before we start moving. Stab trim is set as soon as we have a confirmed trim setting and mentioned and checked during preflight briefing and rechecked during the before takeoff checklist (as is the flap setting a second time).

Nevertheless it can and does sometimes happen that the wrong flap setting is used, as far as i know nobody managed to get airborne without any flaps set at all.

Winter operation is of course something different but we use a completely different checklist for that to double check a correct trim and flap setting as well.
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Old 17th Oct 2007, 22:30
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lucky b*stards getting away with that! If the F/O hadn't realised and selected flaps 5 they would all be dead.
I've thought about what I'd do if I rotated without flaps and got stick shaker. Think I'd select flap 1 as this would cause the LE flaps to extend and the LE slats would go to full extend close to the stall. There's not much difference between flaps 1 and 5, it would give the least trim change, and it's quick to just slam the flap lever into the flap 1 gate. At the same time I'd firewall the thrust levers and lower the nose until the stick shake went away. It would be messy but guess if you're quick then you can get away with it with just a change of underwear!

And I was taught to check the 'triangle' as you line up, of A/T in the top left FMA, the eyebrows, and the FD in the top right FMA. Got the eyebrows and you've got flaps!
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Old 18th Oct 2007, 00:34
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According to my companies SOP, you must select the TO Flaps before releasing the maintenance guy after start. And there is a "slats moving" call out that he must do before leaving.
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Old 18th Oct 2007, 09:43
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like that idea of getting ground crew to call slats running. how does that work at foreign outstations, are they always aware of the procedure?
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Old 18th Oct 2007, 20:38
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Yes. For every base we fly, the procedure is the same. They are trained to leave the aircraft only after this callout.
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Old 19th Oct 2007, 04:05
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I have been told of two incidents where the crew started the takeoff roll without flaps selected, both on B737NG's. One aborted & one continued the takeoff while selecting the flaps - not what I would have considered smart! It must have been a little noisy for a while.

It would appear that Boeing has written the normal procedures to cover the case of de-icing during taxi & therefore not selecting flaps & calling for the checklist until after this is complete, just before takeoff. Some operators or pilots have taken the wording literally & are not calling the checklist until line up on every takeoff, even in areas where you never de-ice during taxi.

IMHO in these cases it is a setup for takeoff without flaps. If you are de-icing you are constantly aware of the aircraft configuration as you are turning packs & bleed off & on; setting stab trim & flaps. If you are just doing a normal taxi & takeoff, & you aren't naturally thinking about configuration unless you have some sort of memory jogger that you use before takeoff.

When I was flying in the part of the world where you never de-iced on taxi, I always called for the checklist when leaving the apron. This meant that the flaps were checked shortly after selection, before they were forgotten. However, there was once where the taxi was very short & busy. I was lining up, about to roll, when the F/O asked if I wanted the checklist. I had clean forgotten to call for it! We had the flaps set, but would have taken off without doing the checklist if it hadn't been for the on the ball F/O.

Reagrding the Config Warning horn, I have also taken off on one occasion without it's protection. I missed the first sign which was no chime from the cabin to advise ready for departure. I was listening on the interphone, so knew that the purser was trying to call. I thought that the chime system had failed & decided to deal with it once we were on the way. I finally twigged when we did a selcal check after TOC & it didn't work either. The Aural Warning C/B was popped. Actually I don't think it was 'popped'. The engineers pull this breaker on ocassions to stop the noise from the warnings when working on certain systems in the aircraft. And then they sometimes forget to reset it.

The trouble with this C/B is that it is right beside the fire extingusher on the F/O's side. If you don't get right over & look almost straight down, when doing the C/B check, you can easily miss that it is out. And if it is out, you will have no config warnings.

I filled a report expecting something to be sent out to all the pilots advising of the traps with this particular C/B during the preflight check, but they mustn't have considered the issue important. Go figure.

Last edited by Oakape; 19th Oct 2007 at 04:38.
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Old 19th Oct 2007, 18:59
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My company selects flaps as part of the before taxi procedure. As a FO I start with the Generators etc and flow down naturally extending the flaps and challenging the Captain ´flaps` which he will confirm 5. The flaps are then checked twice, as part of the taxi checklist and the line-up checklist (where we check config).
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Old 19th Oct 2007, 20:36
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Just another student........
Kudos.......thats the ONLY ( and best way ), to check it.....!!!! Do the before take off checklist as Msrs Boeing recommended it.......right BEFORE you move on own power!!! Reason being minimal runway and taxiway incursions during taxying due the "pseudo" feeling of "all checklists complete". Also maximum focus on ground ops and taxying.......a MAJOR cause of all ground incidents..........DUH......
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Old 19th Oct 2007, 22:54
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The 3 killers

After reading Pprune forums and threads for a few years, I am absolutely amazed that these still deal with checklists, SOPs related to proper flaps positioning for takeoff, and this coming from eminently well qualified pilots, or from airline trainees who are fresh out of training.
xxx
I have flown the line now for 22,000+ hours, and since 1969... of which many years as instructor, in aircraft... or simulator... Yes, at times I was not very "professional" as instructor or line pilot, and failed proper use of before takeoff checks... But one single thing saved me and maybe 500 people in the back from becoming accident statistic...
xxx
The three killers in a jet airplane...
TRIM - FLAPS - SPOILERS
Everytime I line-up on a runway for any takeoff, I crosscheck the 3 killers.
Did you do your checklists or not, does not matter...
With your three killers checked and properly set, you will get the bird off into the air...
Checklists or no checklist completed, SOPs completed or not...
Forgot transponder, you will not crash...
Landing lights ON or OFF, you will not crash...
Galley power not OFF, you will not crash...
Takeoff warning horn INOP... you will not crash...
Cabin "ready" or not, you will not crash...
xxx
In a jet plane, 3 things will kill you on takeoff...
(1) Pitch trim not set (green band)...
(2) Flaps not set (leading edge and trailing edge flaps)...
(3) Spoilers/Speedbrakes not stowed...
Applies to any jet plane, DH Comet II, to A-380, going through Learjets...
xxx
EVERY TIME I LINE UP ON A RUNWAY, I say aloud "TRIM, FLAPS, SPOILERS"...
It saved me a few times in line operations -
Once the trim was all the way nose UP, dont know why, we did set it ok initially.
A few times flaps were still all the way UP... snow and slush situation...
And in training, it saved my life a lot of times, when "rushing" things...
Remember in the old days, we did do training in airplanes, not in simulators...
Even though we completed the before takeoff checks and runway items...
Even though we completed the "abbreviated" training checklist...
I always say "3 killers - trims, flaps, spoilers" when on the runway.
xxx
Saudia does read a "before takeoff prayer" and Insh'Allah... from the Kuran...
Being catholic, I might elect to say "Jesus, Marie, Joseph"...
But for me, it is always and everytime "TRIM FLAPS SPOILERS" for my prayer.
xxx
Now please discuss your check-lists and SOPs "this and that"...
Ready for the "flak" from the XXI Century geeks who now command CRJs etc...
You make me laugh, or, actually cry... Glad to retire soon.
The next takeoff accident will be with a crew who did not read this. SORRY...
xxx
This is what I teach in classroom and simulators SOPs...
You do not do it... in my book, you fail...
In simulators, the 3 killers not verified, your training session is stopped for the day... right then...
xxx

Happy contrails
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Old 19th Oct 2007, 23:29
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Good post, BelArgUSA, but new guys are tuned into checklist, checklist!! My new Chief Pilot does NOT like pilots checking configuration prior to rolling or prior to landing!! "Is the checklist complete?', "Yes", "well, then, what is the need to look again?" Scares me badly!

I might add PITOT HEAT, after NW spun a 727 in, but no one remembers that one. I do, saw the circular crash the next day.

GF
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Old 20th Oct 2007, 00:25
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Boeing normal procedures says to set flaps before taxi (NG), not during taxi. Period.

I love the short taxi CL as we both can concentrate of what's going on outside the aircraft. Three back ups as far as flaps are concerned, 1; set flap before taxi, 2; CL, 3; config warning.

I'm much more worried about the complete lack of challenge and response when it comes to check list reading on the NG.
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Old 20th Oct 2007, 09:23
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Hi BelArgUSA,

I like your "holy trinity". Will pass it on to my students.

Enjoy your retirement when it comes.

All the best,

Fred.
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Old 20th Oct 2007, 13:48
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At Treviso, next to the RW holding point sign is an additional sign saying " Trim / Flaps / Spoilers "

Thats the only airport ive seen that sign.
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Old 20th Oct 2007, 14:14
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To those colleagues who select flaps in the after start, and therefore before taxi: This item will be in the after start checklist. Is it then repeated in the Before Takeoff checklist? What happens if in snowy conditions where taxi-ing with flaps up is required? Airmanship says keep flaps up until just before takeoff. So what do you do with the item in the After Starts?
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