Originally Posted by
Danny
This thread is about to get shut down. Far too many indications of enthusiasts debating the scenarios whilst showing a severe lack of even basic physics understanding.
If you don't understand the concept of kinetic energy then please leave this debate alone. Those that fail to grasp even the rudimentary idea that a collision, whether it was just a winglet striking another part of a bigger aircraft or whatever, involves tremendous forces. It's not Hollywood fantasy.
Spot on Danny. Let's throw a few rough assumptive numbers in here so people can get a clue.
Assumption: Legacy winglet weighs 20kg.
Assumption: MAC was something relatively close to head-on, with a closing velocity of 400m/s (assuming both aircraft were cruising at something like 450kts).
Now, the equation for kinetic energy is:
Note that Ek is proportional to the *square* of the velocity. Plug the above numbers in, and we get an energy in the winglet of 1,600,000 joules.
For comparison, take a 2 ton (2000kg) car travelling at 45mph - say 20m/s. That has an energy of only 400,000 joules - which would be the same number as the winglet energy if the Boeing was stationary WRT the Legacy, i.e. they were on headings 90 degrees apart rather than reciprocal.
How would YOU like four cars at 45mph hitting your office? That's the kind of energy we're talking about, folks. The only reason the Legacy got away so lightly is that the winglet *was* frangible, and the structure failed, as designed, before much of the energy was transferred to the Legacy. It mostly ended up in the Boeing...
(I've had a couple of beers so if I've made any horrific errors of sign or magnitude someone please correct me)
R1