We already have all the gear on board for an effective takeoff acceleration monitor and alert system...IRS for accel achieved + Runway data in the FMC database (to calculate accel required)
All it requires is some clever team to write up the program. Speed tapes have a trend vector - if required acceleration to 80kts is not achieved this vector arrow could start flashing red and a timely stop could be made. It would be inhibited above 80kts. Get on to it Guys!
There have been many T/O performance accidents that have not involved engine failure - the DC-8 60 series (was it ONA or Capitol?) comes to mind that started T/O with the parking brake set comes to mind, and what about the recent 747 at YHZ? - although I don't know the details of that one.
Some time ago there was anecdotal evidence of an interesting T/O by a major 747 carrier at a far-eastern airport. Thrust was set and the a/c trundled off - albeit slowly, down the strip. Things looked pretty tight but it eventually staggered into the air and dragged its @rse all the way to flap retract, when climb thrust was selected and - the a/c came rapidly to life and accelerated away nicely! For some reason the set thrust had been nowhere near t/o thrust and it had gone unnoticed.
We need a simple T/O acceleration monitoring and alert system