Why Would Both Engines Fail On A Commercial Passenger Jet?
A look at the reasons that a passenger aircraft’s engines might fail . . .
What could cause a double engine failure?
Any engine failure is a very rare occurrence, and a double engine failure extremely improbable. But is has happened. Here are some of the factors which have caused double engine failures in the past.
Birds can be very hazardous to aircraft. Flying through a flock of geese caused both engines to fail on US Airways Flight 1549 in 2009 that subsequently landed in the Hudson river in New York. A similar incident occurred in 2008 when Ryanair flight 4102 suffered around 90 individual bird strikes when flying through a flock of starlings on final approach into Rome Ciampino airport. Despite losing both the 737’s engines, the crew managed to land the aircraft on the runway. The aircraft was written off. There is a little a pilot can do to avoid birds other than try to manoeuvre the aircraft around them, but they often seen to late to attempt this.
Shutting down the wrong engine
It sounds difficult to believe, but it has happened. When there has been a problem with an engine, there have been examples of the crew shutting down the wrong engine as a result, leaving both engines failed. It’s not actually that difficult to do, especially when factoring in all the stresses and information sources. A famous example of this was the British Midland Flight 92 crash at Kegworth where 47 people died. Airlines have updated their procedures as a result and the engine shutdown process is now carefully monitored by both pilots.
A fuel leak, or running out of fuel will cause both engines to fail. Air Transat 236 ran out of fuel due to a leak approximately 65 miles from the Azores in 2001. The pilots successfully managed to glide the aircraft to an airbase on the island. In 1983 Air Canda Flight 143 also ran out of fuel when descending through 35,000 feet, due to a fuel miscalculation (the weight of the fuel was measure in pounds instead of kilograms). The pilots successfully managed to glide the aircraft to safety onto a closed runway.
Icing in the fuel tanks could stop the engines from receiving fuel. This happened to flight BA38 in 2008 when ice in the fuel lines caused a dual engine flame out on final approach into London Heathrow. This was found to have been caused due to a an issue with the Boeing 777 fuel system. The quick actions of the Captain in making the decision to retract some of the flaps reduced the drag of aircraft which saved everyone on board.
This is where the ignition of the fuel stops. This could occur in extreme turbulence or very heavy rain / precipitation.
This can damage the engines to the point that they flame out or stops the combustion process. In 1982, British Airways flight 9, a Boeing 747, lost all four of its engines due to ingesting volcanic ash. The aircraft glided outside of the ash cloud and managed to restart its engines before successfully landing in Jakarta.
Believe it or not, there is a checklist on commercial aircraft for entire separation of the engine from the wing. The engine is held onto the wing by a ‘sheer pin’ to ensure the engine separates from the aircraft and protect the aircraft structure in the results of the engine suffering a significant impact.