Qantas Chief Executive Alan Joyce has blamed an engine design fault for the well-documented problems with the A380, VH-OQA.
But, you know, if it really was an engine design fault, as Mr Joyce has said, wouldn’t every single Trent 900 fitted to every A380 show some kind of a problem?
And yet Emirates has inspected their fleet, found no issues, so they continue flying?
So…
Eh up, I just remembered that I have got a PhD in Aerospace Engineering, so I might be able to help here. How lucky is that?!
The first thing you need to know is that when an airline buys an aircraft, they only buy the airframe (either Boeing or Airbus). Then they buy the rest of the components separately from all different companies – engines, landing gear, avionics, interiors, etc.
Qantas bought the A380 and chose Rolls Royce engines.
Emirates bought the A380 and chose GE engines.
That is why Emirates A380’s are still flying, and also why Rolls Royce shares have dropped through the floor.
Hope I didn’t sound geeky then.
Qantas, Singapore and Lufthansa = RR Trent 900.
Emirates and Air France = GP7200 (made by GE & P&W in an alliance).
The failure seen was not your classic “blade-off” which all modern jet engines are designed to contain using muchos Kevlar – this particular incident involved the back-end (high pressure) stages of the engine. The Trent 900 has been subject to a couple of Airworthiness Directives relating to this area, so that may well be relevant.
Also of note are stories that Qantas have now had to replace a number of engines due to issues observed during inspection, whereas the other operators of the same engine have not had to. Qantas purchase the Trent 900 with a higher-rated “plug” (a module that controls the engine performance), allowing them to run the engine at a higher performance level, so that may well also be linked.
What Airbus should be concerned about is the apparent impact of the uncontained liberation of engine parts on the aircraft’s hydraulics (one of the systems was drained by the wing damage) + the lack of ability to shutdown Engine #1 after it landed. Re-routing of some systems in the wing area may well be required to reduce the possibility of this in future.
That said, this incident is nothing new – a look back at the history of pretty much every passenger aircraft / engine will reveal tales of unforseen shortcomings in design that are rectified early in production life.
If you’re interested in such things, I’d suggest you take some time reading some of the detailed reports (published online) by the FAA and AAIB – 2/3rds of them are related to simple things like baggage-cart/airbridge vs aircraft collisions, but there are some interesting stories of various other incidents related to systems design as well.
Also, if you like gossip on incidents like this, try pprune 🙂
Yes, I admit it, I’m an engineering geek.
Annie, I think Daniel sounds slightly geekier than you! 🙂