Structural Integrity
All,
When G-BEBP lost its stab as flap 50 was selected, even though slowing and set up for landing, departure from S&L was immediate, with no recovery prospect. It impacted just beyond the vertical.
If ST-AKW suffered a stab loss, her behaviour would be the same. If the stab was damaged (by the departing cowling), pitch, and not roll control would have been immediately affected. This is not the case.
5N-MAS proved a heavy 707 can fly having suffered Nos 3 and 4 physically depart the airplane, and with the right wing in flames for 12 minutes, to a text book landing at Istres.
N761PA lost 27ft of its RH wing and the No. 4 engine on T/O from SFO when a T3disk ruptured, and the reserve tank exploded. Operation of the inboard high speed airleron was impaired, but the aircraft remained controllable.
When OD-AGO collided with an TAF F-5 in 1979, it lost the entire vertical stabiliser at FL110, with the Captain's comment about "slight control anomoly".
The 707 can suffer complete retraction of the L/E devices (as in a total hydraulic failure), with little effect on an airplane in excess of 130 kts.
The above shows the 707 can fly with major structure missing in the empennage and wing (except the horizontal stab), engines missing, flight controls seriously imparied or missing, or the L/E devides retracted.
There are really only two likely scenarios for this tradegy.
1. The airplane got too slow too quickly after the No. 4 engine failure, and with high power set for its climb, once it started into its right turn towards the failed engine, it kept going, and with the wings vertical, gravity, insufficient time adn altitude did the rest -OR-
2. The departing cowling from No. 3 or 4 impacted a T/E flap, or the T/E flap seperated for some other reason, pulling the aileron bus cables (run just in front of the flap) and applying full right aileron. Remeber both high and low speed ailerons were operable in this regime, and you know the airplane's roll rate.
Take another look at the size of the "object", and its trajectory. Its big enough to be either an inboard or an outboard flap. Does the light "sycamore leaf" cowling fall staight down, or would it not tumble ??
Tweedler