A Matter of Millimeters: The Story of Qantas Flight 32
The Qantas A380 engine disintegration in 2010
On November 4, 2010, a Qantas A380 suffered a catastrophic engine failure minutes after takeoff from Singapore, hurling turbine fragments through the wing and fuselage. The explosion crippled nearly every major system, but the five pilots—with 140 years of combined experience—managed to land the plane safely, sparing all 469 aboard. Investigators traced the cause to a single oil pipe with a wall just fractions of a millimeter too thin. This detailed account explores the manufacturing flaw, the chain of failures, and the design safeguards that prevented a disaster.
How this seemingly tiny defect came about, and how it nearly brought down the world’s largest passenger plane, represent a story equally as fascinating as that of the flight itself.
- u1hcw9nx
Turbine disk failure is one thing that can down a plane, and you can only reduce the probability so much.
Fan blades and turbine blades can be contained by containment cases if they break off, but turbine disks can't. When a disk breaks, it's an uncontained engine failure. A 20 kg disk fragment flying at Mach 1 goes through everything.
Airframes are have a 30-degree fragment spread cone around every disk stage. Airframes are designed so that no single fragment can destroy all redundant systems at once in this zone (flight controls, fuel lines, and hydraulic systems). Jet fuel cannot be stored in the wings in this zone.
- CursedSilicon
One of my favourite memories of flying Qantas when I was younger was the inflight entertainment.
If memory serves, they were celebrating some sort of milestone like "60 years without a fatal accident" or similar. Quite an impressive feat!
I'm unclear if it was directly related. But the Qantas inflight entertainment system on our flight from Sydney to Los Angeles meanwhile contained about 12 seasons of the National Geographic series "Air Crash Investigation" (Mayday: Air Disasters for Americans)
I will admit that show made an 18 hour slog of a flight significantly more enjoyable
- NetMageSCW
Retroactive, but one thing that struck me since they were overweight for landing and their fuel dump was inoperative, why not turn on the leveling pump and pump fuel out the hole in the left tank anyway? It would have lowered weight and improved balance.
- exceptione
> The detailed software allowed them to enter various parameters including the weather, runway condition, and any systems failures, and then calculate whether it was possible to land. But when everything had been entered, the program spit out an unhelpful answer: “no result.”
> When calculating the landing distance, the software applied a generic “operational coefficient” to account conservatively for variations in pilot techniques that could result in less efficient deceleration. The problem, as investigators would later discover, was that the software applied the coefficient again whenever another system failure was added. With so many system failures on the aircraft, the coefficient was applied a total of 9 times, resulting in a calculated landing distance considerably greater than the length of the available runway. However, Check Captain Evans was able to fix the problem by manually entering their actual landing weight, overriding the program’s assumption of a maximum landing weight. By specifying a landing weight in excess of the maximum, the system logic changed to apply the operational coefficient only once — for unrelated and obscure reasons — and lo and behold, when he ran the numbers this time, the computer said they could just barely land on any of the 4,000-meter runways at Singapore Changi Airport, with only 100 meters to spare.
This reeks so much of if-then-else programming as opposed to making a well-typed conceptual model computable.
- seemaze
This remarkable event, along with the an accessible history of the evolution of precision manufacturing is covered in Simon Winchester's excellent book The Perfectionists[0]. The audiobook is narrated by the author, which is quite enjoyable as well.
[0]https://www.harpercollins.com/products/the-perfectionists-si...