hambleoldboy

you mentioned a tech fault regarding takeoff warning system

I mentioned that the failure path with the huge item of RAT PROBE being heated on the ground as a symptom of what was wrong...around post 670.

additional information concerning the strobe lights was brought out, also part of the equation.

I was quite a bit more specific

Jeez guys, who cares who was first!?

Wings1011 brilliant post, well written and outright scary

We now have thanks to many contributions A likely scenario and a lesson to be learned if not several

Just a couple of ideas-----
I have a few thousand hours in the MD-88, line check pilot for a famous southern US airline. We had a procedure where we used circuit breakers as switches. Airplane on ground for more than 3 hours or overnight we pulled "red collared" CBs. Other breakers were "yellow collared" to be pulled in non-normal situations.
Stay with me here:

Out loud say the word "SHOP:


OK, spell it out loud: S- H- O- P


OK, Out loud

What do you do when you come to a red light??




Most answer STOP!!!

You have just been programmed----
Now
We had a crew take off from a famous downtown Washington, DC airport in a 737-800 and on the first callout after gear up, called for flaps 1, VNAV.
Guess where the flaps were?
Two times, the crew responded properly to the checklist challenge
FLAPS ---- 5,5 and a green light
Crew was "programmed" for the response and the previous crew had accidentally pulled the yellow collared CB for the take off warning system. it was early morning and the offending CB was not noticed.
In almost 29,000 hours of flying, there is not much I haven't seen. When any routine is interrupted, mistakes creep in. Most of the time we are simply lucky and catch our mistakes before they catch us.
Again at the previous airline, we had a procedure that required a complete before start checklist any time maintainance had been performed on the aircraft.
Also, the importance of "flows" can't be minimized.
Our flows in the MD-88 were extensive-but the 88 was a very hands-on busy cockpit. With a proper flow, if one thing is in place, then everything is in place.
End result--I'm hoping the crew is found faultless and some bizarre mechanical failure is to blame

actually the test was "What do you do when you come to a green light?

Here's the switch. Do you need to be in the air or not? Seems that some operators may have modded the logic.

[IMG]http://i21.photobucket.com/albums/b2...pas/strobe.jpg[/IMG]

Inquiry silent on report Spanair MD-82 was misconfigured
 

Source Air Transport Intelligence:

http://www.flightglobal.com/articles...onfigured.html


Green-dot

For those in the know:

How many "possitions" does the Ground Control Relay has?

If you "find it in the off possition", could it just have tripped itself? (I.e. is it suppossed to trip under shortcuts or other electrical malfunctions?) Or is it totally neccessary that someone physically puts it in that possition (knowingly or inadvertenly)?

Also, is it in the pilot's mandatory checklist to check that all the circuit breakers (except those turned off for delayed maintenance) are on?

And last: Do manufacturers keep a knowledge base that could be downloaded to a laptop where a technician could type: "probe heater turned on while on ground" and get an answer such as: "check WOW sensor opened or closed", "check gnd relay CB set or out"? Shouldn't it exist?

Two more survivors have been discharged from the hospitals. Only one remains in intensive care in very serious condition.

Justme69, thankyou for all your translations.

The Gnd control relay is a circuit breaker= "on" or "off", popped or in

Forget, some operators may have done that,Idunno. My outfit has not. Strobe's only flashing when nose' s off the ground. And good that is. Always irritates me sitting behind a Boeing lining up at night with those stupid strobes on!

Do any of these airliners have hi-lift and flying control position indicators fitted?

R2-5......c/b L/h Gnd Ctrl Rly
 

@wings1011/L1011

Storia lunga di qualcosa?

:hmm:here you may retrieve some add on`s or supplements in this issue posted by pichu17
#708 Rat,art,atr
#812 Rat probe heater fail
#856 Especulation
#1249 wow
#1272 The same relay, the R2-5

Mosca alta?
For sure
:ouch:

As mentioned earlier, in one of Delta's DFW crashes the FO responded "Fifteen, fifteen, green light" although the flaps were up for takeoff:

http://www.airdisaster.com/special/special-dl1141.shtml

The DL 1141 crew were distracted by a flight attendant chatting in the cockpit and were famously discussing F/A dating habits, mixed drinks and even whether a certain "community organizer" from Chicago was suitable to be President:

http://www.youtube.com/watch?v=TmCtJhCPEeQ

Back in the day... Yep, in the old days you rang every bell and checked every light, pushed all the instrument transfer switches, even ran the trim all the way through in both directions. As you know, in modern Boeings and Airbuses you do little of this, we don't even check fire warnings, it's a maintenance function. I guess you could push up a throttle before start these days but you'd trip off the utility busses and get a call from the back. Some of these old checks were busy work for the FE and we've gradually gone to a "if it ain't broke, don't fix it" streamlined preflight.

The "circuit breakers as switches" has fallen out of favor with many operators as have things like closing the valve on the 02 bottle every night due to the possiblity of inducing a problem that is spring loaded to cause a mishap if the c/b or valve is not repositioned before flight.

So, was the MAD mishap due to a distracted crew with taking off with flaps up and no takeoff warning horn? I think it's looking like a very real possibility.

Excess complacency
 

Good discussion, thanks for sharing. I am a PPL, but an anesthesiologist in real life. Most of our "disasters" are similar to this: violations of the "sterile cockpit" rule, excessive chitchat, and inattention to boring but very basic safety details. Thanks !

Storia lunga
 

For GP7280-POC

I initially did write my first post much more detailed and it took me some time to write it, but it did disappear in the cyberworld somewere when posting it. Therefore the next one I wrote were much shorter. Thats why I called it a long story shorter.....:ok:
Im sorry to have repeated some already printed notification-but I felt my story could clearify and maybe help others in the future

Regards

L1011

Flap indicator
 

For testpanel

Ofcourse the MD80 have a Flap position indicator- Its located @ the center instrument panel- There is NO passenger aircraft flying around that im aware of that does not have one.
Then why it was not noted or why they did takeoff without flap/slat selected if that actually did happened is something completely different. My post is just to clearyfy that in the scenario I described the last resort of protection for human error could or more likely would in this case been out of the way.
Thats the famous swiss cheese syndrom. When all varialble comes together that particulary day it just aint your day and accidents could happen. Accidents as you know usually is caused by a chain of errors and not by a single failure or error.
Just trying to find something that could make sence of how it could happen,

Regards

Wings 1011

Tristar (That was a lovely airplane) Posts
 

Wings1011

Thanks for the very insighful post, abbreviated or not, in not your first language, which must have taken time. SO even more thanks for the perseverance. Should you still have a draft of your initial, more detailed post, I would encourage you to post it because the additional quality detail could only contribute further to trying to get to grips with what caused this awful tragedy. Thanks again for all your inputs.

So as a passenger in the back - if we're taxing to the runway and the flaps aren't extended - do I notify the F/A?

There's that bit of hesitation that everything is normal and you're just a passenger - so what do you know?

But after spending a lot of time on planes and usually sitting in the exit row, if not upfront, I tend to make a note of the flap/slat extension after-start and provide an extra verification before my flight takes off ;)

The last item on our before takeoff checklist, to be completed when the aircraft is lined up on the runway...

Configuration check

Flaps/slats.....set
Speedbrake lever...forward
Stab trim.....takeoff range
Compasses.... compared (and agree with the desired runway)

Do this, and an attempted takeoff without having the aircraft properly configured, is highly unlikely.

So far as I know, there was only one airline that incorporated a configuration check as the last item...PanAmerican.

It still is...:ok:

One of the items of the preflight checks on the 747, which the Flight Engineer carried out; was checking all cockpit circuit brakers set. He also checked all aural warnings including the T/O warning which was activated by the No.3 thrust lever. Further check sequences verified flap, slat and stab positions amongst other things prior to take off.

function test
 

B777300ER:

that check is a reasonable check of system functionality, but the problem becomes a disruption to procedure following an exceptional event in the normal flow of a flight; the crew have returned to blocks for a defect, and in the clearance action for the defect, the aircraft function is unknowingly interrupted.

If the crew redo a check like the thrust level advance prior to start, then they would identify a new defect, but as they would normally do the check on the initial preflight setup, they would have to repeat the check. Humans being adept at finding work arounds and time saving behavioral patterns, tend to short circuit such activities.

On a related point:

The Reason model of causality probably fits to some extent to this event, however, the event also may serve to indicate that the behavior of aviation safety systems are in fact dynamically non linear and also have unbounded chaotic behavior, which results in stochastic or non deterministic system behavior. Accidents can happen.

About the only thing that is simply indicated is that sometimes things don't work out as desired, on spite of reasonable efforts by various parts of the system and reasonable rules and procedures.

regards

MadDogDriver,

Those strobes maybe annoying when someone is lining up but they may just save a runway collision. We used to leave them in auto position to switch on when airborne. After a few very close calls (BA nearly landing on a BMI at LHR) our Sop changed on the BUS to put them on entering the runway. It seems a shame that not all MDs have been modified, because it sounds like this accident may not have happened if that was the case.