Incident Overview
On June 23, 2017, at approximately 1338 eastern daylight time, Delta Air Lines Flight 800, an Airbus A321-211 (registration N315DN), sustained a tail strike while landing on runway 26R at Hartsfield-Jackson Atlanta International Airport (ATL) in Atlanta, Georgia. The scheduled domestic passenger flight operated under Title 14 Code of Federal Regulations Part 121 from General Edward Lawrence Logan International Airport (BOS) in Boston, Massachusetts, to ATL. Visual meteorological conditions prevailed at the time of landing. There were no injuries among the 199 passengers and crew members on board, and the aircraft incurred substantial damage.
Flight Data Recorder Analysis
Review of flight data recorder (FDR) data revealed that the airplane descended below 2,000 ft above ground level (agl) at 1335:55. At that time, the autopilot was not engaged, but the autothrottle was engaged. At 1337:58, the airplane's pitch began increasing from 2° airplane nose up. At 1338:03, the flare law mode activated. Subsequently, at 1338:04.2, the cockpit voice recorder (CVR) captured the automated alert "TWENTY" as the airplane passed through 20 ft agl. Between this alert and runway contact, the captain instructed the first officer to bring the nose up three times.
Sequence of Events
At 1338:06, the autothrottle disengaged. One second later, both main landing gear weight on wheels (WOW) switches transitioned from air to ground. At that moment, airspeed was approximately 130 knots, pitch was about 6.2° airplane nose up, wings were level, and the aircraft experienced its greatest vertical acceleration of 1.89 g. About one second after that, the spoilers deployed, and the main landing gear WOW switches transitioned back to air. The CVR recorded an automated alert "PITCH PITCH" at 1338:08.6, followed by the captain instructing the first officer to lower the nose. At 1338:09, the main landing gear WOW switches returned to ground and remained in that state. Around the time of the second WOW ground indication, the maximum pitch of 9.7° airplane nose up and a vertical acceleration of 1.65 g were recorded. At 1338:10, the CVR captured an automated alert "DUAL INPUT." The FDR showed longitudinal and lateral control stick inputs on the captain's stick for about 3 seconds beginning around 1338:07.5. The nose landing gear WOW status transitioned to ground at 1338:12, and the airplane decelerated using brakes, spoilers, and thrust reversers.