Category: Aviation Safety

Today a preliminary report on Qantas flight QF32 (Airbus A380 VH-OQA) was released by Australian Aviation Safety Bureau (ATSB). On 4 November the flight sustained an uncontained failure of the Intermediate Pressure (IP) turbine disc on engine No 2.

The report reveals many interesting details about sustained damage, flight crew response, a brief history of the flight, cause of the incident and data obtained from flight data recorder (FDR). (link at the bottom)

Following a short summary of events that occured on-board

• The crew reported that, while maintaining 250 kts in the climb and passing 7,000 ft above mean sea level (AMSL), they heard two, almost coincident ‘loud bangs’.
• The crew reported a slight yaw and that the aircraft immediately levelled off in accordance with the selection of altitude hold
• PIC noticed that the autothrust system was no longer active
• Electronic Centralised Aircraft Monitor (ECAM) system displayed a message indicating an “overheat” warning in the No 2 engine turbine. Soon after, multiple ECAM messages started to be displayed. The PIC confirmed with the flight crew that he was maintaining control of the aircraft and called for the commencement of the requisite ECAM actions by the FO in response to those messages.
• Affected engine’s thrust lever was moved to IDLE and a PAN radio call was transmitted to Changi air traffic control (ATC)
• Warning indicating a fire in the No 2 engine that displayed for about 1 to 2 seconds; the ECAM then reverted back to the overheat warning
• The crew decided to shut down No 2 engine; after they had selected the ENG 2 master switch OFF, the ECAM displayed a message indicating that the No 2 engine had failed
• The crew reported assessing that there was serious damage and discharged one of the engine’s two fire extinguisher bottles into the engine
• Flight crew did not receive confirmation that the fire extinguisher bottle had discharged. They repeated the procedure for discharging the fire extinguisher and again did not receive confirmation that it had discharged.
• Crew followed the procedure for discharging the second fire extinguisher bottle into the No 2 engine. After completing that procedure twice, they did not receive confirmation that the second bottle had discharged.
• Continuation with engine failure procedure, which included initiating an automated process of fuel transfer from the aircraft’s outer wing tanks to the inner tanks.
• Engine display for the No 2 engine had changed to a failed mode
• Engine display for Nos 1 and 4 engines had reverted to a degraded mode (indicates that some air data or engine parameters are not available)
• Display for No 3 engine indicated that the engine was operating in an alternate mode as a result of actioning an ECAM procedure
• Crew recalls following systems warnings on ECAM after failure of engine No 2:
  • Engines No 1 and 4 operating in a degraded mode
  • GREEN hydraulic system – low system pressure and low fluid level (one of two primary hydraulic systems – power is supplied by engine-driven pumps on Nos 1 and 2 engines)
  • YELLOW hydraulic system – engine No 4 pump errors (second of two primary hydraulic systems – power is supplied by engine-driven pumps on Nos 3 and 4 engines)
  • Failure of the alternating current (AC) electrical No 1 and 2 bus systems
  • Flight controls operating in alternate law (reduces some of the flight control protections that are available under normal law)
  • Wing slats inoperative
  • Flight controls – ailerons partial control only
  • Flight controls – reduced spoiler control
  • Landing gear control and indicator warnings
  • Multiple brake system messages
  • Engine anti-ice and air data sensor messages
  • Multiple fuel system messages, including a fuel jettison fault
  • Centre of gravity messages
  • Autothrust and autoland inoperative
  • No 1 engine generator drive disconnected
  • Left wing pneumatic bleed leaks
  • Avionics system overheat

Photo: Damage to electrical wiring located in the leading edge of the left wing (punctured by debris)
• Customer service manager (CSM) attempted to contact the flight crew, including through use of the EMERGENCY contact selection on the cabin interphone system. This activated the flight deck warning horn. No associated ECAM message was displayed, the flight crew associated the emergency contact warning horn with the continuously-sounding warnings from the ECAM system and cancelled the horn.
• holding at the present altitude while processing ECAM messages and associated procedures – no immediate return to Singapore – needed holding pattern for about 30 minutes
• 20 NM (37 km) racetrack holding pattern at 7,400 ft east of Singapore
• ATC acknowledged crew that a number of aircraft components found on Indonesian island of Batam
• Second Officer (SO) was dispatched into the cabin to visually assess the damage to the No 2 engine; a passenger, who was also a pilot for the operator, brought the SO’s attention to a view of the aircraft from the vertical fin-mounted camera that was displayed on the aircraft’s in-flight entertainment system. That display appeared to show some form of fluid leak from the left wing.

Photo: Left wing fuel tank damage (punctured by debris)
• SO proceeded to lower deck on the left side of the aircraft to observe damage to the left wing and fuel leaking. The fluid leak appeared to be coming from underneath the left wing, in the vicinity of the No 2 engine and that the fluid trail was about 0.5 m wide. The SO could not see the turbine area of the No 2 engine from any location within the cabin.
• Elected not to initiate further fuel transfer – were unsure of the integrity of the fuel system. Could not jettison fuel due to ECAM fuel jettison fault
• Noticed that the aircraft’s satellite communications system had failed and received ACARS message from aircraft operator that indicated that multiple failure messages had been received from the aircraft
• SCC and PIC made a number of public address (PA) announcements to the passengers indicating that the aircraft had sustained a technical failure, and that the crew were addressing the issues associated with that failure. Subsequently, the SCC and SO returned to the cabin on numerous occasions to visually assess the damage on the left side of the aircraft, and to inspect the right side of the aircraft, and to provide feedback to the cabin crew and passengers.
• It took about 50 minutes to complete all initial procedures associated with ECAM messages. During that time, the autopilot was engaged.
• They assessed the aircraft systems to determine those that had been damaged, or that were operating in a degraded mode. They considered that the status of each system had the potential to affect the calculation of the required parameters for the approach and landing. The crew also believed that the failure may have damaged the No 1 engine, and they discussed a number of concerns in relation to the lateral and longitudinal fuel imbalances that had been indicated by the ECAM.
• Input of affected aircraft systems into landing distance performance application (LDPA) to determine the landing distance required for an overweight landing to runway 20C at Changi Airport of about 440 t, which was 50 t above the aircraft’s maximum landing weight.
  Based on the initial inputs to the LDPA by the flight crew, the LDPA did not calculate a landing distance. After discussion, and in the knowledge that the runway at Changi was dry, the crew elected to remove the inputs applicable to a landing on a wet runway and re-ran the calculation. This second calculation indicated that a landing on runway 20C was feasible, with 100 m of runway remaining. The crew elected to proceed on the basis of that calculation and advised ATC to that effect.
• Crew advised ATC that they would require emergency services to meet the aircraft at the upwind end of the runway, and that the aircraft was leaking fluid from the left wing that was likely to include hydraulic fluid and fuel.
• Crew discussed the controllability of the aircraft and conducted a number of manual handling checks at the holding speed. The crew decided that the aircraft remained controllable
• Lowering of flaps – remained controllable
• As result of the landing gear-related ECAM messages, the landing gear was lowered using the emergency extension procedure and a further controllability check was conducted
• Crew was aware of: reverse thrust was only available from the No 3 engine, no leading edge slats were available, there was limited aileron and spoiler control, anti-skid braking was restricted to the body landing gear only, there was limited nosewheel steering and that the nose was likely to pitch up on touchdown. An ECAM message indicated that they could not apply maximum braking until the nosewheel was on the runway.
• The wing flaps were extended to the No 3 position
• The PIC was aware that accurate speed control on final would be important to avoid either an stall condition, or a runway overrun. Consequently, the PIC set the thrust levers for Nos 1 and 4 engines to provide symmetric thrust, and controlled the aircraft’s speed with the thrust from No 3 engine.
• Autopilot disconnected a couple of times during early part of approach as the speed reduced to 1 kt below approach speed. The PIC initially acted to reconnect the autopilot but, when it disconnected again at about 1,000 ft, he elected to leave it disconnected and to fly the aircraft manually for the remainder of the approach. Due to the limited landing margin available, the CC reminded the PIC that the landing would have to be conducted with no flare and that there would be a slightly higher nose attitude on touchdown.
• Cabin crew was briefed to prepare for a possible runway overrun and evacuation
• Aircraft touched down, the nosewheel touched down within about 6 seconds, the PIC commenced maximum braking and selected reverse thrust on No 3 engine. The flight crew observed that the deceleration appeared to be ‘slow’ in the initial landing roll, but that with maximum braking and reverse thrust, the aircraft began to slow. The PIC recalled feeling confident that, as the speed approached 60 kts, the aircraft would be able to stop in the remaining runway distance. In consequence, the No 3 engine was gradually moved out of maximum reverse thrust. Manual braking was continued and the aircraft came to a stop about 150 m from the end of the runway. The aircraft was met by emergency services.
• After landing, crew commenced to shut down the remaining engines. When the final engine master switch was selected OFF, the aircraft’s electrical system went into a configuration similar to the emergency electrical power mode. That rendered many of the aircraft’s cockpit displays inoperative, and meant that there was only one very high frequency (VHF) radio available to the crew.
• Just before the cockpit displays went blank, a number of the flight crew noticed that the left body landing gear brake temperature was indicating 900 °C, and rising. After some initial confusion about which radio was functioning, the FO contacted the emergency services fire commander, who asked for the No 1 engine to be shut down. The FO responded that they had done so already, but was advised again by the fire commander that the engine continued to run.
  • recycled the engine master switch to OFF but the engine did not shut down
  • use of emergency shutoff and fire extinguisher bottles but the engine did not shut down
  • tried to activate a series of circuit breakers in the aircraft’s equipment bay, the engine did still not shut down
  • attempts were made to reconfigure the transfer valves in the aircraft’s external refuelling panel, in an effort to transfer fuel out of the No 1 feed tank, and starve the No 1 engine of fuel. However, due to the lack of electrical power, that was not possible.
  • Ground engineers attended the aircraft and attempted a number of methods to shut down the engine, each without success
  • Finally, the decision was taken to drown the engine with fire-fighting foam from the emergency services fire vehicles. The No 1 engine was reported to have finally been shut down about 2 hours and 7 minutes after the aircraft landed.
• Fire commander indicated that there appeared to be fuel leaking from the aircraft’s left wing. The FO advised the commander of the hot brakes, and requested that fire retardant foam be applied over that fuel. The fire commander complied with that request
• four of the wheels on the left body landing gear had deflated
• 55 minutes after landing – after the fire risk had decreased – passengers disembarked via stairs on the right side of the aircraft, using only a single door (No 2 main deck forward door), to keep remaining doors clear in case of the need to deploy the escape slides.
• Disembarking took about 1 hour

Download: ATSB Preliminary Report (PDF)

Source/Photos: ATSB