Air France A321 at Paris on Sep 12th 2011, tail strike on landing

Last Update: April 27, 2012 / 15:03:30 GMT/Zulu time

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Photo of Air France F-GTAT, Airbus A321 — Air France F-GTAT, Airbus A321 (Photo credit: Thomas Naas Photography / Flickr / License: CC by-nd)

Incident Facts

Date of incident
Sep 12, 2011

Cause
Tail strike on landing

Airline
Air France

Flight number
AF-7661

Departure
Marseille, France

Destination
Paris Charles de Gaulle, France

Aircraft Registration
F-GTAT

Aircraft Type
Airbus A321

ICAO Type Designator
A321

An Air France Airbus A321-200, registration F-GTAT performing flight AF-7661 from Marseille to Paris Charles de Gaulle (France), was on an ILS approach to Charles de Gaulle's runway 26L. The aircraft was fully established and stabilized while descending through 1000 feet AGL in landing configuration, Vapp was 143 KIAS with Vref at 136 KIAS, the captain (43, ATPL, 8,538 hours total, 2,844 hours on A320 family, 284 hours on type) was pilot flying, the first officer (42, ATPL, 4,586 hours total, 4,000 hours on A320 family, 506 hours on type) was pilot monitoring. The aircraft crossed 50 feet AGL at 136 KIAS, 1.8 degrees nose up pitch angle and about 800 feet per minute sink rate, at 35 feet AGL the captain initiated the flare applying a bit more than half stick back pressure, the pitch angle increased from 1.8 to 4.2 degrees nose up within one second, at the same time the thrust levers were brought into the idle detent, a second later the first officer calls "il tombe, il tombe, il tombe, il tombe" (it falls, it falls, it falls), the aircraft just descends through 20 feet AGL at 137 KIAS, within a second the captain applies full back pressure on the stick, the pitch angle increases from 4.2 to 7.7 degrees nose up. Another second later the automated call "RETARD" is being heard, another second later at a speed of 130 KIAS and 400 feet per minute sink rate the main gear gets compressed and the spoilers deploy, the flight data recorder records a vertical acceleration of 1.9G, the pitch of the aircraft increases further to 8.4 degrees nose up, the pilot flying applies forward pressure on the stick about a third of the travel. The gear gets uncompressed again, the spoilers remain extended, the nose reaches a maximum angle of 9.1 degrees nose up, the thrust levers are put into reverse idle. About a second after indicating uncompressed the gear struts indicate compressed again, speed is 130 KIAS, vertical acceleration 1.75G, the pitch reduces, the thrust reversers are unlocked and the thrust levers get placed in maximum reverse. 5 seconds after the second main gear touch down the nose gear touches down and the aircraft rolls out without further incident. There were no injuries, the aircraft received substantial damage.

The French BEA released their final report in French concluding the probable causes of the accident were:

insufficient control of flight parameters on very short final and flare, the captain continued the landing although airspeed reduced below Vref. The reflex inputs on the control stick caused a bounce, the extension of spoilers subsequently caused a touch down at too high a pitch angle.

Contributing factors were:
- the lack of callouts of (speed, pitch) deviations by the pilot monitoring
- the lack of indications of pitch angle limits on the PFD
- the lack of pilot training specific to the aircraft model

The BEA reported that between 100 feet AGL and touch down the head wind component decreased by 13 knots (and continued to decrease), the left crosswind component of 17 knots gusted up to 27 knots with no significant vertical wind component registered.

The BEA analysed that the approach was fully stabilized until 50 feet AGL. Just prior to initiating the flare the aircraft gets slightly high (above the glideslope), the airspeed drops to below 136 KIAS, however, there was no call from the pilot monitoring indicating the speed reducing below Vref. The speed reduction probably was the result of the decreasing head wind component, there was no adjustment of thrust levers. When the aircraft descended through 20 feet the back pressure on the stick did not arrest the resulting increasing sink rate but just increased the pitch angle to 8.4 degrees, led to hard touchdown (1.9G) and a bounce. The deflected spoilers increased the pitch angle to 9.1 degrees resulting in a tail strike. According to the aircraft manuals a tail strike would occur at 9.7 degrees pitch angle with the main gear fully compressed, the BEA argued that this discrepancy is likely the result of (certified) measurement inaccuracies of +/- 0.352 degrees for the pitch angle plus the bending of fuselage at touchdown.

The standard operating procedures of the airline required the pilot monitoring to call "PITCH" if the pitch angle exceeds 7.5 degrees, no such call was recorded however, the pitch angle reached and exceeded 7.5 degrees 2 seconds prior to first touchdown.

The BEA analysed that the A320 simulator experience, commonly used for the A321, can not be applied to the A321 due to the longer fuselage of the A321 especially with respect to landing geometry and performance.

A low bounced landing recovery would require to maintain normal landing attitude, NOT increase pitch angle, be aware the extension of spoilers creates a pitch up moment thus requiring the crew to not permit a pitch angle increase in order to avoid a tail strike and continue the landing keeping the engines at idle.