I know this isn't really totally transferable, but we hear a lot about airplane accidents having "pilot error" causing 70% of all accidents (including those accidents where poor design was a MAJOR contributor to the error). Of course the natural assumption is, "Get the idiot pilot out of the cockpit". But I wonder about a statistic that I have never seen and I wonder if it is even recorded: How often does the pilot save the day? Everything from the pilot noticing something and resolving it before it even becomes an issue to correctly dealing with a full blown emergency.<br>    Who here thinks a computer could have dealt with the emergency US Airways flight 1549?<br>   An additional note here. Airbus designers have deliberately designed a computer program that prevents the pilot from restarting a badly damaged engine even if that engine CAN still run with reduced thrust because doing so will lead to more damage and more expense.<br>    I don't know if,  Sullenburger had been flying a Boeing if he could have restarted the engines and gotten enough thrust to make it back to a runway, but in the 1980's (I think) A Boeing 747 flew into a volcanic ash cloud couching all four engines to fail. After flying back into clear air (and at very low altitude) the flight crew was able to restart all four engines. Though they were badly damaged they provided just enough thrust for the plane to make a safe emergency landing.<br>    Volcanic clouds are invisible on radar. Should this same thing happen to an A380 (and it will happen sooner or later) and there is no runway withing glide distance. Well just hope Sullenburger is your pilot.,(reply>), @JLDoctorWho<br>I'm done. We clearly have different concepts of what "damaged" is. Personally I consider "damaged" to be ANY condition that degrades the engine performance.<br>     The volcanic ash melts inside the engine coating the inside surfaces and abrading moving parts. This causes a dramatic (and in some cases complete) reduction in performance.<br>   This to me id damaged. A dirty engine can be cleaned and put back into service. A damaged engine must have the damaged parts replaced or repaired before it can be put back in service.<br>   I will say this again: I never said they COULD have restarted the engines. I said they MIGHT have been able to restart them had the computers allowed it.,(reply>), @Eric Taylor "I think you need to look up what volcanic ash does to engines. It does a hell of a lot more than make them dirty."<br><br>It really doesn't. What happens is that the ash solidifies into goop inside the engine however the major components of the engine are undamaged. This basically means the engine is dirty but mechanically intact. That is why restart was so easy once the ash cooled and some of it broke away.<br><br>" However pilots have been able to run engines even after bird strikes on Boeing aircraft, even Geese."<br><br>You can't compare all bird strikes just like you can't compare all missile strikes or all bullet impacts. Sully's engines each ingested multiple birds. Two or three birds are much worse than one bird.,(reply>), @JLDoctorWho<br>I think you need to look up what volcanic ash does to engines. It does a hell of a lot more than make them dirty.<br>    As I stated, I don't know if the crew could have restarted the engines if it had been a Boeing. They were in the water before they completed the restart checklist.<br>   My point is that Airbus engineers consider pilots too stupid to not run a damaged engine even if that engine can supply some thrust.<br>    My point applies much more to the volcanic ash disaster than this one.<br>   However pilots have been able to run engines even after bird strikes on Boeing aircraft, even Geese.,(reply>), @Eric Taylor Please refer to my use of the word "basically." The engine damage caused by ash is not catastrophic. It basically just makes the engine dirty.<br><br>On the other hand bird strikes do cause catastrophic damage and it is a well established fact in the industry that bird strikes cause more damage than the engine manufacturers claim it should. The geese impacted by the airbus where both bigger than the required test and more numerous.,(reply>), @JLDoctorWho<br>Volcanic ash certainly does cause engine damage. When volcanic ash (which is made of very small particles of rock) enters the turban engine it is melted inside the combustion chamber. The now liquid rock coats the inside of the engine with glass which greatly reduces the trust the engine can provide.<br>    The engine MIGHT still run (if you are very lucky) and it MIGHT provide some thrust if you're lucky. But it defenatly damages the engine.<br>    As to bird strike, turban engine designs are tested for their resilience to bird strike damage. The engines must continue to provide a cretin percentage of it full power thrust (not including afterburners) this my contention that the engines should have still worked.<br>    Maybe the engines were completely wrecked, but it's something we may never know.