Created Thursday, Aug 8th 2024 15:46Z, last updated Thursday, Aug 8th 2024 15:46Z
A west Atlantic Boeing 737-400, registration G-JMCV performing flight NPT-2876 from East Midlands,EN to Aberdeen,SC (UK) with 2 crew, was departing from East Midlands' runway 09 when the tail contacted the runway surface. The aircraft continued the flight, climbed to FL240 and landed on Aberdeen's runway 34 about 45 minutes after departure.
The aircraft remained on the ground in Aberdeen for about 13 hours, then operated the return flight NPT-2877 before the aircraft remained on the ground in East Midlands for 3 days.
On Aug 8th 2024 the AAIB released their final bulletin concluding the probable causes of the serious incident were:
The crew used incorrect loading figures to calculate the aircraft performance at departure. The aircraft was approximately 10 tonnes heavier than anticipated and the PF therefore commenced the takeoff rotation 15 kt too slow. Due to the lower speed the wing did not develop sufficient lift for the aircraft to takeoff as expected and the tail struck the ground.
The AAIB analysed:
The crew used the data from a loadsheet for a previous flight to calculate the takeoff performance figures for the aircraft. This led to the takeoff performance being calculated for a mass 10,082 kg less than the actual mass of the aircraft at departure. Therefore, the commander, as PF commenced the takeoff rotation at 123 kt as opposed to the 139 kt required for the aircraft’s actual mass. The FCTM advises that pilots should make a smooth continuous rotation at VR towards a pitch attitude of 15° nose-up. The stabiliser trim setting was more nose-up than for the correct mass resulting in pitch control forces being lighter than anticipated by the PF, possibly contributing to the pitch rate peaking at 5°/s just prior to the tail striking the ground. As the aircraft rotated the airspeed was too low to generate sufficient lift for the actual mass of the aircraft. The aircraft did not therefore lift off at the point in the rotation anticipated by the crew but, instead, lifted off as the PF continued the rotation. As described in the FCTM the aircraft tail struck the ground damaging the tail skid and a drainage mast.
The commander recalled feeling a small bump during the takeoff but saw no other abnormal indications. Once the after takeoff checklist was complete the crew discussed the possibility of a tail strike or a load shift as being the cause of the bump. The commander was confident that the rotation and lift off had been normal, with no abnormal indications or flight parameters he considered liable to cause a tail strike. His workload was high due to the inexperience of the co-pilot so with the aircraft handling normally the commander decided to continue the planned departure as this also kept the deck angle stable in accordance with the load shift guidance in the OMB. Continuing the planned departure and climb also avoided the increased workload of an immediate diversion.
In the cruise at FL240 with the workload much reduced, the commander revisited the symptoms after the co-pilot had visually checked the cargo. With the suggestion of a load shift excluded the commander decided to action the Tail Strike QRH procedure out of an abundance of caution. Concerned about exposing the co-pilot to the very unusual task of depressurising the aircraft at high altitude the commander decided to first descend and then complete the QRH actions. Sufficient fuel remained to carry on to the destination which, in considering the workload, the commander decided to do. The sector was short and so comparatively little time would have been saved by diverting.
The aircraft then flew an uneventful approach to Aberdeen and, after landing, was checked by the commander and the damage identified. The crew reviewed their paperwork and realised that the loadsheet signed by the commander was not the one they had used for calculating takeoff performance.
