Airbus is in trouble....

[Normy]

Folks, the disintegration earlier this month of a Rolls-Royce Trent 900 engine on a Queensland and Northern Territories Air Service [QANTAS] Airbus A380 is having huge repercussions.

This "company" faces a serious challenge right now. Their premier product, the A380, of which 21 have been built... has 1/3 of the worlds A380 fleet grounded right now. Lufthansa, Singapore Airlines, and Emirates have the same Trent engine. Other operators of the 380 have a more reliable General Electric GE90 motor that has been on the wing of the Boeing 777 since 1994.

The A380 development costs were initially to be recouped when the 151st aircraft was sold. That number has slipped to over 250 now, and with this engine fiasco...it might slip a bit farther.

What is happening is that an oil leak is occurring on this engine that causes the case to actually bend inward....contacting the turbine. This turbine, about 3 feet across, spins at 10,000 rpm and has the equivalent of a blow torch blowing on it- typical turbine interstage temperatures at takeoff on modern jet engines are in the 500 celsius range.

Rolls-Royce had problems with this engine in development. One of their test engines came apart on the test rig during development, and they've tried to "patch" the problem since. This engine design is high-tech, but it is based upon the Trent engine that is reliable as hell on the Boeing 777. They simply screwed something up on the A380 variant.

[Airline pilot inside knowledge: There are three manufacturers of aircraft engines: Pratt & Whitney, General Electric, and Rolls-Royce. Each one has its strengths and weaknesses. Most airline pilots prefer the General Electric product. I flew CF6 engines at Southern Air Transport for a while, and you started them up at your initiation point, and then shut them down when you got to your destination. They never gave ONE BIT of trouble! Best engines in the world, in my estimation. Pratt & Whitney engines are more powerful than GE motors, but they are like Ferrari's: very temperamental [the exceptions are the JT8D and the engines they make in Canada], very complex, and you have to watch them like a hawk. The PW motors I operated at Kalitta Air never gave me a problem, but I always watched the temperature gauges carefully; On these, if you pull the throttles to idle, they may "silent stall" and then you can watch the temperature gauge go from the middle of the gauge to red line in about 5 seconds. If you don't catch it in time and it goes above 950 Celsius, then the $2 million engine is toast.]

Smoking a $2 million engine tends to piss off your boss-

Anyway, in the industry, the word on the street is that you get your best performance from Pratt & Whitney's very complex engines [they don't hang engines on the A380], you get more reliability from GE's dirt-simple motors, and you get the best fuel burn from the RR engines. The three-shaft design of the RR is more efficient, but it is also much more expensive. While the complex PW motor can produce 50% more thrust than its rated power for up to five hours, the GE will only do it for 30 minutes, and the RR will come apart nearly instantly if you ask it to make more power than it should.

There you have it-

N!

[Normy]

Incidently, Rolls-Royce the car company and Rolls-Royce the aircraft engine company have been separate for several decades. Really, the only connection is the name.

N

[old man neri]

Source: http://www.salon.com/technology/ask_the_pilot/2010/11/18/qantas_emergency_revisited/index.html

The following rundown is drawn from second- or third-hand accounts, but I take it to be reliable. This, in a nutshell, is what the crew of Flight QF32 was dealing with.

-Complete, uncontained failure of No. 2 engine. As I noted in my original story, a four-engine jet can operate safely with the loss of one, and, in most cases, even two engines. Still, an engine failure is never taken lightly, especially one that has sprayed the airframe with red-hot pieces of metal.
-Shrapnel hole on one of the left wing-flap fairings (those long, canoe-shaped structures that jut from the bottom of the wing). This hole was described by once source as "big enough to fit your upper body through."
Large shrapnel puncture clear through the forward section of the left wing. (Debris entered the bottom of the wing and exited, several feet later, out the top.)
-Assorted electrical problems. Electrical bus No. 2, normally powered via the No. 2 engine, will automatically switch to bus No. 1 in the event of failure. (Such auto-transfer capabilities are standard in commercial aircraft to keep important systems running if their normal power source is lost.) For reasons still unknown, this transfer didn't happen. Electrical buses 3 and 4, meanwhile, will supposedly power bus 2 in the event of an auto-transfer failure, but this didn't happen either. End result: Various components/systems/instruments were inoperative when they shouldn't have been.
-Total loss of all fluid in one of the plane's two main hydraulic systems. This required, among many other complications, a manual extension of landing gear.
-Substantial leaks in two of the plane's left wing fuel tanks. Literally thousands of gallons were pouring out.
Electronic and/or mechanical failure of important fuel transfer functions. This prevented the crew from addressing a major fuel imbalance -- and subsequent flight stability issues -- brought on by the leaks.
-Additionally, a substantial amount of fuel became trapped in the aft, so-called trim tank, leading to a serious center-of-gravity issue during descent and landing. The crew received repeated caution messages about this impending out-of-balance condition, but was unable to address it.

Malfunction of the fuel jettison system. This hindered the ability to reduce weight for the emergency landing. Overweight landings entail higher landing speeds and a longer rollout distance (and though it's unlikely, there can be structural ramifications). Very overweight landings entail very high landing speeds and very long rollout distances.
-Partial failure of leading edge slats. These are the panels that slide forward from the leading edge of the wing. Similar to flaps, they increase lift and allow for slower takeoff and landing speeds. The lack of slats increased the plane's landing speed even further, perhaps beyond the rated groundspeed limits of its tires.
(Planes slow down in stages, deploying flaps, slats and gear at particular target speeds. These speeds are usually obtained from the flight management system, but reportedly there weren't enough data fields on the input screen to account for all the necessary corrections. The crew did the best it could, entering what it thought were the most critical corrections to come up with reasonable numbers.)

-Partial failure of speed brakes and ground spoilers. These are panels that lift from the wings to aid in deceleration, both aloft and on the ground. Not only was the landing roll going to be unusually long due to the aforementioned high approach speeds, but the ability to decelerate would also be hampered.
-Loss of brake anti-skid system. Ditto.
-Inability to shut down the adjacent, No. 1 engine using normal or emergency ("fire switch") methods. This was not discovered until after landing, but it meant there had been no fire protection available for the No. 1 engine after the uncontained failure of the one directly next to it. Had there been shrapnel damage to this engine as well, causing a fire, there would have been no way to shut it down.
Plus a host of other, smaller problems and failures.
I have been told that the crew chose to commence its approach not because the problems were sorted out, but because of worries over fuel balance and center-of-gravity.

In the end, the plane used virtually all of the 13,000-foot runway at Changi Airport. Brake temperatures neared 1,000 degrees while fuel poured from the punctured left-side tanks.

The crew elected not to evacuate as the emergency trucks were on hand instantly, but a fire was a real possibility.

Really the biggest issue was about stopping. Pilots practice overweight or high-speed landings all the time in simulators, but this was a perfect storm of multiple failures.

[Scuba Steve]

I think the bigger challenge will be the AOG work to patch up the front spar.

[rick-l]

They're not in trouble. Rolls Royce will be scrambling. Pratt and GE are happy.

The Anatomy of the Airbus A380 QF32 near disaster – Plane Talking

Edit: I was thinking Pratt and GE is one engine on the A380. Engine Alliance.

[Hugh R]

Thanks for the write up Normy, very informative.

[Flieger]

Thanks for the new info and links. I am still curious to know more about the mechanics of the oiling failure and subsequent engine structural failure. The bigger turbine is just too massive for a system that works on smaller engines?

[nostatic]

bah, it was just a chain tensioner issue...or maybe head stud pulling. Either way, no big deal.

[MBAtarga]

wouldn't a cool collar help?

[Racerbvd]

Bet the engine in this wouldn't fail....