Technical – ATSB Report – “QF32 – The story behind the story”

My book “QF32” was published in July 2012, about one year before the ATSB published its report into QF32.   Because of this mismatch in time, I was not permitted to publish information discovered by the ATSB that was not already available in the public domain.  Information I included in the “Stub Pipe” chapter was therefore limited only to my knowledge and best guesses.

I have just become aware of a video of an ATSB presentation delivered in February 2016, well after the ATSB report was released.   This presentation details exactly what happened in the chain of events that led to the engine failure.

I recommend this fifty minute presentation to people who want to know the  exact cause for the uncontained engine failure.

Fortunately, the ATSB presentation agrees with and validates all I wrote in “QF32”.  The report also included things I did not know.  The investigator said the three primary fragments of the IP disk exited the engine at a speed of 880 metres per second (880 * 1.98 = 1742 knots or M2.63),  2.63 times the speed of Sound.

Of the three fragments of the Intermediate Pressure Turbine (IPT) disk that left the engine at Mach 2.6, only two impacted the fuselage.  As they left the engine, these two pieces severed both engine thrust links (that transmits thrust to the engine strut), bent the $1m engine strut, then cut and energised hundreds of sub-pieces of shrapnel that in turn damaged other parts of the aircraft.

Let’s put the kinetic energy of these two pieces into perspective.  The kinetic energy of the complete 160kg IPT turbine equals 1/2 mass multiplied by the velocity squared.   80 kg x 880^2 = 62 million joules.  This is the same energy as the muzzle energy of  71,000 .357 Magnum rounds.(62,000,000/873).  The two pieces that hit the aircraft represented about 210 degrees of the 360 degree disk, equivalent to a 41,000 magnum assault.

The ATSB  does not blame people or organisations.  It simply finds causes so that the industry can learn and implement lessons to prevent recurrences.    This philosophy has great application for resilience in

  • other industries, such as medicine.
  • your personal relationships and lives.

Seven years after QF32, I still hold my greatest respect for Airbus, the A380, my airline and especially Rolls-Royce.  I visited the Rolls-Royce production plant in Derby, UK just two weeks before its Trent 900 engine exploded on QF32.   My confidence in Rolls-Royce has continued unabated and I hope to visit my friends at Rolls-Royce and tour their facilities again soon.

I recommend this video for the technically minded.

I send you my best wishes for 2018.

(My next called “Fly!” is about resilience, is now with Penguin editors and is due out on the 4th September 2018)

Frank Ogilvie, father of the A380, in front of the A380 wing he designed, at the Airbus Wing Factory (Photo: Airbus)

12 comments

  1. Michael O Connell · · Reply

    Captain, I have also read your wonderful first book. I could never make out why they could not put out engine number one?
    Mike o Connell

    1. Thanks Mike for your good question.

      For engine number one, independent pairs of dedicated wires failed from the:

      1. ENG MASTER switch to the Minimum Pressure & Shutoff Valve (in the engine’s hydraulic metering unit).
      2. ENG FIRE push button to the Low Pressure Fuel Valve located in the engine pylon.

      I knew that these switches used independant hard wires, (not computer networks) to control these critical valves. So when these switches failed to work, it was then that I appreciated the extent of damage to the multiple pathed wiring looms.

      Best wishes – Rich

  2. Michael O Connell · · Reply

    Nice to be able to read your opinion on this wonderful aircraft.

    As I had worked at Heathrow for 44 years as ground handler with Air Lingus, I have seen and witnessed things like the arrival of the Pan Am 747 to the A380 Aircraft.

    I once witnessed a check captain ticking off a second officer on Pan Am arrival at LHR. Taking him to the back of my bus and saying, “what the hell were you thinking of the way you landed that kite like that. You deadhead back to Washington tomorrow before you fly again”.

    I knew I felt safe then. And now you came along Captain De Crespigny and made it all more safer.
    Kinds Regards Michael o’Connell (age 71)

  3. Mark Dyson · · Reply

    Hello Richard,

    Thank you for this update.

    As an ex fitter and turner I found the video very interesting and a revisit of some problems in my precision machining career. I understand from experience that a jig/clamp can move in a machining process. A fundamental aspect of machining is to secure the work piece in such a manner that it wont move under the machining forces but that the forces of clamping itself will not cause other issues.

    I think RR could have found the issue by measuring the relative positions of M and AA from the inside before the pipe was welded in to position. Possibly that is what is currently done to ensure the issue is not repeated.

    One obvious question is how many other components were also incorrectly machined, I assume RR have followed that up. Thanks again for an enjoyable insight.

    Mark Dyson

  4. Joe Average · · Reply

    It’s really impressive that the aircraft was hit by two rough equivalents of 152 mm naval AP shells fired from point-blank range (kinetic energy-wise) and survived.

    1. I agree Joe. No aircraft is designed or required to take two pieces of disk. This is why QF32 was a Black Swan Event.

      For interest, certification rules require protection in the event of a rotor burst as follows:

      • Single One-third Piece of Disc over an angular spread of ±3º relative to the plane of rotation of the disc
      • design precautions to minimise, the risk of catastrophic damage due to non-contained engine rotor debris.

      This should include the position of the engine with respect to critical components or regions of the aeroplane such as:

      1. The other engines (especially those located on the same side of the aeroplane);
      2. Fuselage pressurised hull and other primary structure;
      3. Flight deck region;
      4. Fuel system/tanks;
      5. Essential control systems, including primary flight controls, electrical systems, hydraulic systems and shut-off means;
      6. Engine fire extinguisher systems; and
      7. Instrumentation essential for continued safe flight.
      8. Refer to “JAR 25.903 (d)(1)” and “ACJ No. 2 to JAR 25.903 (d)(1)” for more info

  5. Excellent video presentation- many thanks.

    I’m puzzled though about the reference to Rolls-Royce. My recollection of the Four Corners QF32 program is that RR new about the possible offset with some of the oil feed pipes but chose not to reveal that information. I think the QF32 co-pilot even went so far as to say that RR should not be in the aviation industry if it new of a potential fault and kept quiet about it.

    From the ATSB investigation it is now known that the introduction of a second datum point from the design drawing to the manufacturing drawing enabled the build process to introduce a potential fatal error with exact alignment of the oil feed tube.

    Are you able to clarify whether or not the Four Corners program point about RRs knowledge of the offset was fact or speculation at that time?

    It seems odd to me, as a lay person with a passion for aviation, to hear you praising the manufacturer of a product that *could* have killed you! 😉

    Sincerely

    1. Dear Rupert,

      I understand the complexity and risks of designing, building and operating the highest technologies and latest generation jet engines.

      I could write two twenty page documents about the designs, aerodynamics and operational stresses faced by the Trent 900 Fan Blade and High Pressure Turbine Blades (HPTB). I own both of these. These are the two most complex components in an A380.

      Do you know each of the 70 HPTBs mounted on the HP disk on each Trent 900 engine:

      • is cooled with 800 degree celsius engine bleed air
      • sits at about 1,000 degrees celsius
      • melts at 1,200 degrees celsius
      • is impacted by exhaust air at 1,580 degrees celsius
      • is exposed to 18 tonnes centripetal force (its turbine spins at 12,000 RPM)

      HPT Blade
      To put these facts into perspective, try extracting 900 horsepower from a an ice block frozen in an oven heated to 600 degrees celsius for 17 hours a day, 365 days a year for seven years (2500 cycles/365). (The blades have a design life of 15,000 hours. In practice they last 2500 cycles.)

      But wait – there’s more. The construction (70 processes) and aerodynamics (supersonics and shockwaves) of the RR Trent 900 fan blade is equally as impressive.

      If you are interested in these technicalities (facts, designs, working lines …) of latest generation jet engines, then I recommend the 300 page book “The Jet Engine” by Rolls-Royce. Working Lines

      I hold the highest respect for Rolls-Royce.

      • Henry Royce and Charles Rolls formed “Rolls-Royce Ltd” in 1906. Charles Rolls also knew the risks of flight. He flew with Wilbur Wright (4 mins 28 secs) at Camp d’Auvours on 8 Oct 1908. Charles died on the 12 July 1910 as a result of an air crash at Hengistbury Airfield Bournemouth when the tail of his Wright Flyer failed. Charles Rolls was the first Briton to be killed in an aeronautical accident.
      • Rolls-Royce changed the outcome of WWII. The Merlin engine was the best piston engine ever put into a fighter. When the Americans replaced the Mustang’s Alison with a Merlin and fitted drop tanks, only then could the Mustang protect bomber missions into Europe.
      • Rolls-Royce engines named after UK rivers (Trent, Avon …). RR engines have powered the best piston and jet aircraft that have ever flown (Concorde, Airbus and Boeing and military aircraft ..)
      • Engines are perpetually being modified and improved. Changes are staged – not every fault can be fixed immediately. I think Rolls-Royce would never permit a known failure to persist if they knew the consequence in our case ($500m+ for RR)
      • I have visited Rolls-Royce production facilities at Derby (UK) and Seletar (Singapore). I have seen their corporate knowledge and experienced the fellowship that exists between aviation’s designers, builders and operators.
      • These relationships are built upon trust.

      For all these reasons above – I trust Rolls-Royce.

      Get used to risk because risk is vital for our existence. Aviation is laden with risks. Change is risky. Only those that adapt and change survive.

      I was very sad to hear of Astronaut John Young’s death this last week. When asked about the risk of flying on the space shuttle Columbia for the first time in 1981, Young said, “Anyone who sits on top of the largest hydrogen-oxygen fueled system in the world, knowing they are going to light the bottom, and doesn’t get a little worried, does not fully understand the situation.”

      I have no doubt that engines (from all manufacturers) will fail in the future. This is an accepted threat that has been risk-assessed and mitigated appropriately. I have every confidence that pilots will recover from these events safely when they occur.

      Nevertheless things happen when you put 500 people into a thin composite tube, sitting on top of hundreds of tons of fuel and push it through the air at 85 percent of the speed of sound in an atmosphere that supports conscious human life for 8 seconds.

      Get used to risk because risk is vital for our existence. Aviation is laden with risks. Change is risky. Only those that adapt and change survive.

      Pilots accept, are trained, prepared to identify, rate and live with risk. We accept and are used to things that “happen” as part of our job and are confident of the outcomes. Safety statistics prove my view of aviation being safe – last year was the safest in aviation history. Every visit to a hospital has the same risk as 490 average commercial aviation flights.

      People who are not prepared and confident to handle “things” should chose a more comfortable industry than aviation.

  6. James I Fraser · · Reply

    Hi Richard,

    Thank you for this update. I’m sure you had fun with the pistol calculations! I did follow your suggestion, and watched the video and enjoyed it, but was disappointed that the diagrams were hard to read. Please is there a higher quality version – say 720 HD or higher?

    Best wishes,

    James

    17″ MacBook Pro.

    1. James I only discovered the video today. I’ll try and find a higher res version. Rich

  7. I am looking forward to your new book this year.

    1. So am I Aukahkay. The publisher gave me 18 months to write 80,000 words about resilience. I took 33 months and delivered 180,000 words. Penguin are editing down the text, starting another phase in my life.

      I’m looking forward to September and will release more information as the date approaches.

      rich

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