B77L, Copenhagen Denmark, 2011
B77L, Copenhagen Denmark, 2011
On 17 April 2011, a Boeing 777F bounced three times during an attempted landing at Copenhagen during which the underside of the aircraft was damaged by two tailstrikes. The second occurred during over-rotation for a go around commenced after thrust reverser deployment, with 760 metres of the 3300 metre-long runway remaining. The Investigation observed that a go around initiated after thrust reverser deployment was contrary to an express prohibition in the aircraft type FCOM. It was noted that the aircraft commander was an instructor pilot and that both pilots had less than 200 hours experience on the aircraft type.
On 17 April 2011, a Boeing 777F (B-2078) being operated on cargo flight from Shanghai to Copenhagen by China Cargo Airlines was observed to bounce on an initial touchdown after a day Visual Meteorological Conditions (VMC) approach to runway 22L at destination. After two more bounces and two more touchdowns, with reverse thrust activated after both the first and third touchdowns, the aircraft made a go around, becoming airborne with 760 metres of the 3300 metres long runway remaining. The aircraft was positioned for a further approach to the same runway and the landing which followed occurred "without further problems". Damage to the underside of the fuselage was subsequently discovered.
An Investigation was carried out by the Danish AIB. Recorder data was downloaded from the SSCVR and the QAR and was used to inform the Investigation. CCTV recordings from airport security cameras provided a visual record of most of the landing attempt.
It was found that the aircraft commander was an Instructor Pilot but it was not established whether the First Officer was being supervised using that authority or disclosed which pilot had been PF during the event. Both pilots had substantial flying experience but very little on the aircraft type - the commander a total of 132 hours and the First Officer a total of 185 hours. The former had made 3 landings in the three months prior to the accident and the First Officer 28 in the same period.
The flight was uneventful and the approach to runway 22L at Copenhagen was normal. The weather report issued whilst the aircraft was on approach gave 29013KT 9999 FEW024 BKN027 12/06 Q1023 NOSIG. The aircraft passed 1000 feet agl on final with the AP off and the A/T engaged and with an airspeed of 152 KCAS (Reference Speed (Vref) 148 KIAS) and a rate of descent of 830 fpm.
During the flare, the PF increased the pitch attitude and touchdown occurred with it recorded at just under 5 degrees at Vref - 5 knots. N1 was above Idle and a bounce occurred during which the ground spoilers automatically retracted and the auto braking system disarmed followed. After two further bounces, a third and non-bounced touchdown occurred with the engine N1s around 34% and the ground spoilers and the thrust reversers were deployed for 11 seconds, although the data suggested only at reverse idle. As the aircraft slowed, the pitch attitude gradually increased to 10.5 degrees and the rear fuselage stuck the runway. The PF recognised the increasing pitch attitude and "decided to initiate a go-around". The ground spoilers were retracted, the reversers were stowed and the pitch attitude was reduced to 7 degrees. At this point, with approximately 1700 metres of runway ahead and at 117KCAS, engine thrust was re-applied. However, as the airspeed rose, pitch attitude was allowed to increase to almost 12 degrees and second tailstrike occurred. Lift occurred from the tailstrike at 140 KCAS which was 8 knots below the applicable V2 speed. It was considered that the extent of the resulting structural damage was attributable to the fact that the low speed had resulted in greater than usual compression of the main landing gear (MLG) and to the consequently reduced ground clearance which this caused.
During the subsequent initial climb, the Engine Indicating and Crew Alerting System (EICAS) annunciation for a tailstrike occurred and the crew responded by performing the corresponding abnormal Check List and advised ATC about the tailstrike indication stating that there were no resultant aircraft control issues. The Rescue and Fire Fighting Services were put on standby and the second approach continued to an uneventful landing.
Damage found to the aircraft belly sections 47 and 48 was described as "substantial" and extended from stations 1980 back to station 2286, a distance of approximately 8 metres. In several places, the fuselage skin had been breached and the inside of the aircraft was visible. There was damage to the frames and structure inside the aircraft, including at the rear pressure bulkhead.
It was noted that the Boeing 777 FCTM and FCOM both contained unequivocal statements to the effect that once reverse thrust has been initiated following touchdown, a full stop landing must be made.
The opinion of the AIB was that when the go around was initiated with 1700 metres of runway ahead "the remaining runway was sufficient and safe to make a full stop". It was considered that the decision to initiate a go around "could be a result of a landing sequence, where the flight crew at first experienced a landing with three bounces, secondly an increasing pitch angle which wasn’t corrected properly by elevator input and consequently leading to the tail strike". It was also considered that when the pitch attitude was allowed to increase after the final touchdown, the crew would have had a very limited forward view and this had "probably caused an uncertainty of how much remaining runway was available for a full stop".
The formally stated Conclusion of the Investigation was that:
"After the third bounce and at touch down, the PF didn’t prevent the pitch angle from increasing. 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."
The Final Report of the Investigation was published without the inclusion of any Safety Recommendations
- Loss of Control
- Landing Flare
- Tail Strike
- Rejected Landings
- Thrust Reversers: Flight Crew Guidance
- Automated Cockpit Guidelines (OGHFA BN)
- Adherence to SOPs
- Crew Resource Management
- Cockpit Automation - Advantages and Safety Challenges
- Tail Strikes: Prevention, Boeing AERO Magazine article, Q1/07