Something else.....
Hi all,
I've taken the time to read 20 pages of posts. Some more "apt" than others to be sure i don't kick in open doors or appear to be a quick poster.
Here are some reasons why I'm leaning more and more to extraordinary circumstances in the emergency phase of this flight.
Here a few facts about the MD-80 and this particular situation. Some haven't been mentioned before, some have.
1. Contrary to some posts and article the MD80 is a VERY safe plane. Especially in this scenario because,
2. Together with the MD-11, (dunno about the DC-10), the MD-80 is one of the very few aircraft equipped with the "dial a flap" system allowing the optimum use of ANY flap setting for a specific runway (e.g. Flaps 3.8°). Meaning that at the long runway, that particular flight wold have had a VERY high rotation speed because of very low flaps settings. Maybe even less than 5°!. This system of course must be used by the airline. The high speed does not bode well in case of an RTO due to extra mass, but the high speed and low flaps are invaluable in an N-1 situation and airborne.
3. The MD80 has conventional controls, and were the rudder to lose hydraulic pressure (in this case due to damage, as the rudder receives hydraulic pressure from thr #2 system) it would automatically revert to a control tab setup. The high rotation speed in this scenario would benefit the control tab operation.
4. The MD80 has 2 independant hydraulic systems, one AUX pump in the #2 system (because of the importance of the rudder), PLUS a transfer pump that is able to trasfer hydraulic pressure from one sytem to the other.
5. The MD80, contrary to some erroneous articles is highly dependant and highly redundant as can be seen from point 4. This model was newer than some A320 even, throwing away the notion that old planes are unsafe. Remember the 777 engine shutdown problems? The A320 flight control computer woes in the late 80's and early 90's? The MD80 had nothing of the kind. The AA MD80 grounding was because they neglected to perform an AD note that had been issues for at LEAST one year.
6. A system on the MD80 automatically reduces rudder movement with increasing speed, helping the pilots in eliminating the need to pay extra attention to rudder overuse.
7. A reverser deployment between V1 and V2 I think is indeed one of the most horrific scenrios a well trained crew can face. But the obvious mention of and explosion and/or fire rules that out "in my opinion".
No, in my opinion there must be something else we don't know yet (actually we don't know jack sh*t). It may have been an uncontained explosion severing important control cable to the rudder. It may also be incorrect procedures followed for this situation. One other thing the crews did have going against them "probably" was the fact that being a long runway, they would have been derating the engines. On the MD80, when you derate, you lose the Automatic Reserve Thrust feature. Of course this, together with runway length, temps, any MEL items, winds and more, are automatically taken into account in the load sheet software and runway analysis/takeoff speeds and weights. But it's still a small tool they could have had. Even so, there's another system called the ATR (automatic Thrust Restoration) which "should" have set the thrust of the remaining engine at least to G/A thrust in this particular scenatio.
Other than that, the only thing I can see as working against the crews that fatefull afternoon, was if MAYBE the RAT sensor was measuring errouneously and this sending false data to the thrust rating computer. But it's a wild assumption (as is most of what I'm saying as we simply don't know yet). Lastly, the MD80 is loooong. Small elevators, swept wings and a very narrow wheel base. She's NOT an easy plane to fly.
Lastly I want to point out that my post is intended as information to those interested in a more technical view and not those fed by newspapers. It's not my view of what must have happened. I'm an airline pilot and in any case deeply mourn the loss of life and know that no matter how many times you enter a sim, life throws curves at you. My conelences to those affected, and let's at least hope we can all learn from this devastating situation.
Xander