Report: Air France A319 at Paris on Sep 23rd 2009, go-around nearly goes down
An Air France Airbus A319-100, registration F-GRHU performing flight AF-2545 from Moscow Sheremetyevo (Russia) to Paris Charles de Gaulle (France) with 85 passengers and 6 crew, was performing an ILS Category I approach to Charles de Gaulle's runway 27R in fog, visibility of 3000 meters below scattered cloud ceiling 200 and broken cloud ceiling 300 feet, autothrottle was engaged and the autopilot had captured both localizer and glideslope at 3000 feet. Subsequently both autopilot and autothrottle were disengaged, the flight director remained engaged in approach mode and the approach was flown manually by the captain (pilot flying). Descending through 2170 the gear was selected down and full flaps deployed. When the airplane descended through 400 feet AGL the flight director modes changed to LAND, airspeed was 132 KIAS (Vapp 128 KIAS) and pitch angle 0.7 degrees nose up. At 200 feet AGL, the decision height, the captain did not see the runway ahead and decided to go-around. When the airplane descended through 150 feet AGL at 132 KIAS the thrust levers were placed into the FLX/MCT detent, the engines spooled up from 45 to 85% in about 5 seconds, the airplane pitched up to 5.6 degrees nose up, the flaps were selected to 3. 4 seconds later the pitch angle had reduced to 4.6 degrees nose up, the autopilot 1 was engaged - autopilot mode was still LAND - and the gear was selected up. At that point the airplane had reached 170 feet AGL at 145 KIAS. 5 seconds later the thrust levers were placed into the CLB detent, the airplane is still at 170 feet AGL and the airspeed was 161 KIAS, the nose pitched down 0.6 degrees nose down. 2 seconds later the height reduced to 127 feet at 169 KIAS, the attitude had reached 3.9 degrees nose down. The autopilot gets disconnected, a ground proximity warning "Sink Rate" is issued. At the same time the crew communicated their decision to go-around to the tower, the controller cleared the airplane to 3000 feet and to continue on runway heading. The crew did not read back, the tower repeated the instructions two times before he received the read back. The airplane descended further to a height of 76 feet at a speed of 182 KIAS, the aircraft pitched up to 8.1 degrees nose up producing a vertical acceleration of 1.65G, the airplane begins to climb and the ground proximity warning ceases. 1 second later the pitch increases through 9 degrees nose up with an airspeed of 184 KIAS and the master caution activates probably because of maximum flaps speed being exceeded (185 KIAS). The thrust levers are retarded to a position close to IDLE while the airplane climbed through 650 feet AGL at the maximum recorded speed of 192 KIAS. 15 seconds the autopilot gets engaged, the nose pitches down to 2.5 degrees nose up, the thrust levers are placed into the CLB detent, then the autopilot gets disengaged again and the pilot flying pulled the stick. 13 seconds later the thrust levers are placed to IDLE, the pilot monitoring selected an altitude of 4000 feet into the master control panel. When the airplane climbed through 1600 feet, the pilot flying called for the autopilot and placed the thrust levers into the CLB detent. The autopilot again pitched the aircraft down and is disengaged after 2 seconds. Flaps were now selected to 1 and the flight stabilized. The crew subsequently performed an ILS Category III approach and completed a safe landing.
The French Bureau d'Enquetes et d'Analyses (BEA) released their final report in French concluding the probable cause of the serious incident was:
Loss of altitude due to
- the use of the autopilot in an inappropriate way
- the non-activation of go-around mode due to the thrust levers being placed into wrong detents
- lack of monitoring of pitch angle by the crew
Contributing factors were:
- inaccuracies in the wording of the documentation of the procedure
- deviations from the procedure regarding operating limits
The captain (53) had 14230 hours flying experience thereof 3800 on type and 3627 in command on type. He was certified for CATIII approaches.
The first officer (42) had 4176 hours flying experience thereof 684 on type. He was certified for CATIII approaches.
The BEA analysed, that the autoflight system remained in LAND mode all time because the thrust levers were never placed into the TOGA detent. Only TOGA cancels all previous modes and activates the go-around mode.
The autopilot mode therefore continued to descend the aircraft while the changed thrust setting increased the speed. The desire by the captain to engage the autopilot suggests that he wanted to reduce his high workload. The recommendations by the operators also suggested the use of the autopilot. During normal operation the TOGA detent is very rarely used. After placing the thrust levers from nearly IDLE into the FLX/MCT detent (which is a long way the BEA annotates) the engines reacted as wanted, following the autopilot activation the crew was surprised however about the reaction of the aircraft. It is likely that the crew focussed on the speed and the pending flap overspeed and did not notice the flight mode announciations. The crew attempted three times to engage the autopilot while still in the wrong flight mode.
According to the Flight Crew Operating Manual by Airbus a go-around from manual flight control should be done by advancing the thrust levers into the TOGA detent and according flight control inputs. Once a positive climb is established, the crew should read the flight mode announciators and verify the modes.
The operators manual did not mention that the flight mode announciators should be read and verified, however, general guideline required every change in the flight mode announciation should be called out.
The BEA analysed that in the phase of a go-around the pilot flying is focussed on the trajectory of flight and work memory checklist items therefore has reduced capacity for verifying the flight mode announciators. The changes would be more easily seen by the pilot monitoring, the standard operating procedures did not distribute the tasks appropriately taking the work load and capacities of crew members into account.
The BEA listed another similiar incident during which the crew placed the thrust levers into the FLX/MCT detent instead of the TOGA detent, see Report: Jetstar A320 at Melbourne on Jul 21st 2007, descends towards runway despite go-around initiated. In September 2006 the crew of an Airbus A320 commenced a go-around at 50 feet AGL following a precision approach but failed to spot the autopilot had disengaged. In March 2007 the crew of an A330 initiated a go-around at Abidjan but failed to control the altitude and pitch angle resulting in a sharp nose down rotation and a ground proximity warning.