A scenario
How about:
Possibly fatigued crew, with CM1 doing his LOE.
At commencement of TKOF roll, CM1 commands "Set takeoff thrust".
CM2 hits the APPR/LAND switch instead of the AUTOFLIGHT switch which engages the ATS. (For those not familiar with the MD11, the APPR/LAND switch is a smaller switch above the AUTOFLIGHT switch in the center of the FCP, which is above the ATS OVRD OFF switches). At the same time, CM1 advances the throttles, with the expectation that the ATS will drive the throttles to the correct position hence computed takeoff thrust; however with the ATS not engaged, takeoff thrust is not achieved.
T/O CLAMP does not annunciate on the FMA at 80kts, which goes unnoticed by the crew, and, thrust is only about 80% of that required of the Tflex as set in the FMC.
End of the runway is appearing and V1 not yet attained - CM1 pulls back on the stick with a resultant tail strike and aircraft fails to become airborne, and the rest, regrettably, is history.
For those with access to a MD11 sim, try the above scenario - same result as at ZSPD.
I still want to know WHY.