Minneapolis and presumably checked the system there, but was not required to check it upon departure from Detroit. (Enough time had elapsed that the CVR had overwritten the Minneapolis predeparture briefing.) After the accident the FAA required that the system be checked prior to each takeoff. Analysis The flight data recorder and physical wreckage showed that the flaps and slats were retracted. There was no indication that the takeoff warning system had sounded, although later tests on the undamaged unit showed normal operation. The best evidence the NTSB could find that the unit was inoperative was the possibility of a single tripped circuit breaker, but it could not be conclusively determined if, or when, the breaker had tripped and if the crew running the prestart checklist could have detected it. Reconstruction of the actual takeoff showed normal acceleration up to rotation. With flaps set the DC–9-82 normally will lift off between six degrees and eight degrees nose-up pitch. The accident airplane stabilized at 11 degrees to 12 degrees pitch and lifted off at 168 KIAS. This is the 1987 NTSB report diagram showing the ill-fated taxi and flight path of Northwest Flight 255. NTSBhttp://www.pilot-usa.com http://www.pilotblulink.com http://www.pilotblulink.com http://www.pilot-usa.com