17th of April 2011
A Boeing 777-F6N was operating a cargo flight from Shanghai (China) to Copenhagen (Denmark) with a crew of four. After an uneventful flight from Shanghai, the aircraft was vectored onto the approach of Copenhagen's runway 22L
The damage as a result of the two tail strikes (Source & © HCLJ)
The aircraft was established on the approach to runway 22L at 1000 feet AGL while being manually flown, with the autothrottle engaged. With an airspeed of 152 knots, the vertical speed was 830 feet/min. The aircraft was flared to reduce the vertical speed, which was 160 feet/min at touchdown with an airspeed of 143 knots and a pitch attitude of 4.6º. The aircraft bounced back in the air, causing the auto brakes to disarm and the ground spoilers to retract. The aircraft bounced and touched down a second and a third time. After the third touchdown, the ground spoilers extended and the thrust reversers were deployed by crew selection. 11 seconds later the reversers were fully deployed, and the aircraft decelerated, as the pitch angle increased to 10.5º the tail of the aircraft struck the runway and a go-around was initiated.
The reversers were stowed and the spoilers retracted at the initiation of the go-around the pitch angle was reduced to 7.0º, while the indicated airspeed was 117 knots. While thrust was increased this caused a pitch up momentum, resulting in a pitch angle of 11.9º. As the aircraft lifted off a second tailstrike occurred, which was indicated to the crew during the climb out by a "TAIL STRIKE" Caution. The crew performed the necessary checklists for a tail strike and a go-around. ATC was informed about the tailstrike and go around. Subsequently, a second approach to 22L was flown and an uneventful landing followed.
Reconstruction and event pictures from the investigation report
The tailstrike was investigated by the Danish investigation board, the HCLJ, their report is available by clicking here. Several statements were made by the HCLJ based on the B777 Flight Crew Operating Manual (FCOM) and Flight Crew Training Manual;
Warning: After the reverse thrust levers are raised, a full stop landing must be made. If an engine remains in reverse, safe flight is not possible
To avoid the risk of a tail strike, do not allow the pitch attitude to increase after touchdown
Applying excessive nose-down elevator during landing can result in substantial forward fuselage damage
They concluded their report as follows;
"After the third bounce and at touch down, the PF didn’t prevent the pitch angle to increase. The lack of forward elevator control input caused the first tail strike. During the GA, the aircraft was rotated to a pitch angle of 10.2° which caused the second tail strike. The tail strike was prolonged as the pitch angle increased to 11.9° with a V2 speed minus 8 knots, which prolonged the time with a compressed main landing gear and less aft tail clearance."
Quick Access Recorder data of the two approaches (Source & © HCLJ)