[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!