A few comments on performance (a bit late perhaps) to answer a few earlier posts on flap selection ... despite several posts advising that there are too many variables and too many assumptions (... and to a point I agree). So, let me make one assumption: operations normal (as per a cargo airline - carry as much freight as possible because that's how we make money).
A B747-200 (used GE engines as no P&W JT9 figures)
8800ft runway, approx. 400ft amsl, +10 deg C, 5kts HW
Flaps 20 = MTOW 348.0T (... note: zero wind = MTOW 344.5T)
This is field limited max take-off weight.
I think I read earlier that Steve Anderson, MK rep, stated the cargo weighed 103T - so that's what I will use (note: I cannot find that reference now, so please correct me if need be).
Basic Weight = 158T (conservative after MK have stripped it)
Load = 103T (the big question mark!?)
ZFW = 261T (Max ZFW either 267T or 272T)
Fuel = 84T (assumes 6hr flight time plus an hour, 12T)
TOW = 345T (everything legitimate so far)
MAX thrust would be required - no derates.
Speeds: (V1: 147) Vr 161 V2 171
IF Flap 10 was selected in error, Vr 167 V2 178 would be the V speeds at a FLAP 10 setting for 348T. Note: V1 becomes irrelevant and to a point so does the field limited MTOW since the take-off has been continued - all we are concerned about now are the speeds required to get airborne. I am trying to show that, all other things ops normal, a B747 would, in this case, fly if flap 10 was selected instead of a planned flap 20. Rotating 6 knots early would NOT have resulted in this accident.
However, as is coming to light the aircraft never came close to these speeds with "all engines operating normally". Why?
Why are we hearing some reports of 53T- 60T cargo, and other reports of 103T? It points more and more to a gross error in weight of the cargo.
But, as with most accidents, I don't think there will be one isolated event but rather a chain of events that caused this.
Finally: to those who have been discussing the alleged missing wing/fuselage fairing (or not): one or both may be missing; T/O and LDG performance penalty: negligible!
B REEL