It was hard to miss the front-page headlines in almost every paper around the world last week when a massive engine exploded on a Qantas Airways A380 superjumbo jet. Early in my career, I worked on the design team for the GE CF-6 engine, also an immense device. So the news blasts caught my attention for 2 reasons: (1) I wanted to make sure the plane landed safely, and (2) I wanted to make sure it wasn’t an engine I had somehow touched.
The Qantas issue raises the question of just how reliable jet engines are (Ch.17). This particular engine, the Trent 900, made by Rolls-Royce was developed for the Airbus double-decker A380. But is is still what we call an “immature engine”, which has yet to meet expected levels of reliability. It is installed in only 21 planes (meaning 84 engines are in use). Other A380s use the GV7000 engine, jointly developed in the US by GE and Pratt & Whitney. Just for background, an A380 retails for about $300 million, of which $50 million is the cost of engines.
Qantas immediately grounded its A380 fleet for engine testing by Rolls-Royce experts. Rolls, according to the linked WSJ article has “been buffeted by a series of design and reliability issues affecting engines it supplies for other jetliner types”.
That brings up another related reliability issue. Later in my career, I worked at NASA headquarters and wrote a series of case studies on the Space Shuttle. The Shuttle has a reliability of 0.98 overall. This, of course, translates to a major disaster in 1 out of every 50 flights….which has indeed been the reality, with Challenger and Columbia exploding during 130 or so flights to date. You may want to discuss the Ethical Dilemma in Ch.17 that relates to such a 98% reliability.
Discussion questions:
1. What has taken place since this article was published?
2. Compare the reliability of a jet engine or plane to a Shuttle flight.
