Incident Overview
A Northwest Airlines Boeing 757, operating as Flight 336, experienced a tail strike during takeoff from Detroit, Michigan. The aircraft scraped the tail cone area of the fuselage on the runway when the pilot did not maintain sufficient ground clearance during rotation and takeoff.
Flight Data Recorder Analysis
The flight data recorder provided pitch data indicating the rotation rate. According to the recorded data, the aircraft's pitch changed by 5.997 degrees in one second, followed by a change of 4.922 degrees in the next second.
Manufacturer's Guidance
The Boeing 757 Flight Operations Manual states that "normally...approximately 3 degrees per second is a good rotation rate." The manual also notes that "rotating at too fast a rate for existing conditions and/or an early rotation can result in a tail strike."
Conclusion
The incident resulted from the pilot's failure to maintain adequate ground clearance during the rotation and takeoff phase, leading to the tail cone scraping the runway surface.