It’s less likely that any unbalance rotations would create criticla resonance in the wing structure; the fan will be turning (and thus the unbalance will be at the frequency of) tens of thousands of RPM (1000’s of Hz), while the resonance modes of the wing structure are going to be on the order of single digit frequencies. It’s more likely the actual unbalance reaction force that’ll put loads on the wings, and the shear pins are designed to shear free before the wing structure tears apart. In other words, the shear pins holding in the engine are strong, but are designed to have marginally less strength than the wing itself.
I can’t believe this thread has gotten this far without making an obigatory Donnie Darko reference. Okay, I’ll do it: “28 days… 6 hours… 42 minutes… 12 seconds. That… is when the world… will end.”
That taken care of, sure, there’s a danger that a falling engine might pose some hazard to someone on the ground. But despite the fact that it’s a highly critical failure, the likelyhood of occurance is very, very low, and most likely to occur (like most airliner failures) on take-off or landing. Designing an engine to fragment after detacting from the airframe would be extremely difficult (I’d venture to say virtually impossible) and would then just create an expanded fly-down hazard of marginally less dangerous debris over a wider area. Better to kill just one kid in his bedroom than a schoolyard full of children, non? Other schemes like putting parachutes or the like on an engine are functionally problematic (how would you attach the lines and assure that the chute isn’t dragged into the intake) and would increase weight and maintenance. So instead we live with the extremely unlikley hazard of jet engines falling out of the sky, which is less likely to terminate your life than the drunk driver in the lane next to you or the improperly wired GFCI outlet in your bathroom.
“I’m voting for Dukakis.”
Stranger
