Departure and V-Speed Entry
The flight crew briefed the departure, completed taxi-out and pre-departure checklists, and entered V-speeds (V1 139 knots, Vr approximately 143 knots) into the flight management system (FMS). Both crewmembers' primary flight displays (PFD) showed the V-speeds with standard blue lines, with no discrepancies noted. The captain entered V2 speed (approximately 143 knots) into the flight control computer in the glare shield and set 250 knots as the extended speed to 10,000 feet msl. The first officer did not recall being distracted during the checklist or before takeoff procedures.
Takeoff Roll and Speed Display Issue
The flight crew requested and received clearance for departure on runway 04. The pilot flying (PF) aligned the airplane on the runway and applied standard takeoff power. At 80 knots, flight instruments were cross-checked and V-speeds were correctly displayed on the PFD. The first officer checked the engine diagnostic page to observe #2 engine vibrations. According to the first officer, when he looked back at the PFD, the V-speeds were not displayed, and V2 had reset to 100 knots. The first officer did not look at the speed index (correct raw speed data) on the left side of the PFD.
Rotation and Rejected Takeoff
The first officer called "V1, rotate," and the captain responded with an aircraft pitch of approximately 12 degrees. The captain realized the airplane was not climbing or accelerating properly. The first officer noted airspeed was approximately 120-125 knots (below V2) and called for the captain to lower the nose. The captain lowered the nose and executed a rejected takeoff by pulling the throttles to idle. The flight control computer automatically applied maximum auto brakes, the airplane slowed, and the captain taxied the airplane off the runway. Neither crewmember recalled the aft end of the airplane striking the runway.
Post-Event Actions and Maintenance Log
The flight crew deplaned and entered the discrepancy in the Aircraft Maintenance Log (AML): "rejected T/O due to FMS speeds dumping and blue A/S line rolling back to 100. Rejected @ 120 knots. Raw data still indicated properly." They then departed the airport.
Weight and Balance Data
The flight release weight and balance indicated a takeoff gross weight of 297,184 pounds and a takeoff center of gravity of 24.9.
Digital Flight Data Recorder (DFDR) Findings
The DFDR revealed the following:
- The airplane became airborne for about 4 seconds. During the takeoff roll, pitch attitude reached 13.4 degrees nose up, with control column position recorded as 7.1 degrees aft and elevator position as 16.6 degrees trailing edge up.
- Pitch attitude decreased to approximately 6 degrees upon touchdown of the left and right main landing gear, at which time the airplane experienced a vertical acceleration of 1.844 g.
- Airspeed was recorded as 114 knots when the nose gear initially left the ground, increasing to 131 knots. Following nose gear touchdown, maximum recorded airspeed was 138 knots.
- Engine 1 and 2 thrust reversers were briefly unlocked before both were unlocked again and remained in that state.
- Longitudinal acceleration reached -0.584 g and lateral acceleration reached -0.151 g during the rejected takeoff sequence.
Post-Inspection Results
According to the operator's representative, test results for the Flight Control Computer, Flight Management Computer, Flight Warning Computer, ECAM, Flight Augmentation Computer, and Signal Generator Unit found no faults. Examination of the aircraft found no anomalies that would have prevented it from operating per design prior to the tail strike.