Just passing along info. so don't kill the messenger.
How controllable was QF32 during the emergency?
November 21, 2010 – 11:33 am, by
Ben Sandilands
There have been some fairly dramatic claims made about the controllability of QF32 after the disintegration of the inboard No2 Rolls-Royce Trent 900 engine on November 4 after it took off from Singapore for Sydney.
While I was travelling and out of communications Airbus released a statement on this.
It has been described, I think fairly, as ‘defensive’ by some observers. But it is also a reason to use some common sense in considering this gravely serious in-flight incident.
Here is the Airbus statement:
A380 / RR TRENT 900 – QANTAS VH-OQA INCIDENT ON 4th NOVEMBER 2010.
FROM : AIRBUS FLIGHT SAFETY DEPARTMENT TOULOUSE
Subject: A380 / RR Trent 900 – Qantas VH-OQA incident on 4th November 2010
Our ref.: QF32 AIT 3, dated 17th November 2010
This AIT is an update of the AIT 2 following the in-flight engine failure during flight QF32 from Singapore to Sydney, on 4th November 2010.
This AIT has been approved for release by the Australian Transport Safety Bureau (ATSB) who leads the on-going ICAO Annex 13 investigation.
The second RR inspection program applicable to the Trent 900 engine family and covered by EASA Engine Airworthiness Directive has been published allowing continuous operations of the fleet. Together with its partners, Airbus is providing support to the operators for engine logistics to minimize interruptions to the fleet.
One single high energy fragment is considered from a certification requirement viewpoint. The damage assessment has established that the IPT disk released 3 different high energy fragments, resulting in some structural and systems damage, with associated ECAM warnings. Therefore the crew had to manage a dynamic situation.
Despite the situation, amongst the various available systems supporting the crew to operate the aircraft and return safely to Singapore were:
- Flaps remained available (slats were jammed retracted).
- All flight control surfaces remained available on the pitch and yaw axis.
- The roll control was ensured through: (a) on the left wing: inner aileron, spoilers 1, 3, 5 and 7; (b) on the right wing: mid and inner ailerons, spoilers 1, 3, 5, 6 and 7.
- The flight control laws reverted to Alternate law due to the loss of the slats and of some roll control surfaces. Normal law was kept on longitudinal and lateral axes.
- Flight envelope protections were still active.
- The autopilot was kept engaged till about 700 feet Radio Altimeter, time at which the crew took over manually. Flight Directors were ON.
- Manual control of engines 1, 3 & 4 was maintained till aircraft stop.
- Landing in SIN took place about 1 hour 40 minutes after the engine 2 failure with flaps in
configuration 3.
- Normal braking was available on both body landing gears with antiskid, and alternate braking without antiskid on both wing landing gears. The crew modulated braking in order to stop close to emergency services.
- After the aircraft came to a stop, the reason engine 1 could not be shut down has been determined: 2 segregated wiring routes were cut by 2 out of the 3 individual disk debris.
It would have been useful if Airbus had gone into more detail about any problems that were occurring in the capacity of the damaged airliner to transfer fuel between tanks, or in fact, the need to do so during what was a very cool headed and methodical handling of the stricken flight by its pilots.
However it ought to be obvious that the pilots were always aware of the fundamentals of maintaining stable flight while they dealt with the exceptional situation that they were in. The flight remained within the required control envelopes until it landed, and stopped where the crew wanted it to stop, beside the fire engines.
To infer that there was a risk of the centre of gravity causing them to lose control is obviously silly, since were managing all of the many risks that had arisen in a logical but timely manner, and they touched down when they chose to, and stopped where they chose to.
None of which is to say that the experiences of the QF32 won’t result in subsequent changes to the A380 to deal with such a catastrophic engine failure in the future. But the first step is to drag the mystery of what Rolls-Royce did to these engines, and why, and even to which ones, out in the open, and fix them.
