Blow Bolts Or not?
 

I saw on a Tv programe some thing about Blow Bolts. They were Looking in to see if they would work on 747`s and was under going testing this was a few months back and was wondering if they r on such planes now what they do is the Pilots can release one of there engines if it catchs fire and they carnt put it out. thanks.. D.Lucas:confused:

Dropping an engine looks like a quite stupid idea :
- you might hurt someone on the ground
- yor CG will probably be out of limits afterwards (most twins with wing mounted engines have weights attached to the pylon during production to avoid them falling on their tail, for fuselage mounted engines it´s even worst)

To learn more about blow bolts you should look up some space technology pages in the web (maybe the NACA-report server contains some usefull information) because they are widely used in spacecraft design.

Thanks BTW they were designed for droping them over the sea not over land. Thanks

I wonder how they would ensure the reliability of these fuses would exceed the reliability of the fire extinguishing system in a nacelle.

Sounds to me like the consequences of a an exploding bolt system malfunction may be worse than the cure.

Having a little experience of exploding bolts, it's actually fairly straightforward to design a system which, in both senses, is tolerant of both a single undemanded bolt actuation, and similarly a single bolt that fails to blow when required - if you want to consider double/triple failures that can be done as well, it's just a bit more complex.

A bigger problem might well be finding any existing ground crew able to deal with explosive devices on civil aircraft. Or airports comfortable having them sat on the pan - particularly given the huge amount of EMC affecting radiation swashing most airports, which can be bad news in conjunction with electrically operated explosives.

G

ok thanks for all your help :)

Can actually lose an engine on the 747 and it will remain flyable.