explosive bolts

[brian]

I decided some time ago to not use the standard tipup canopy hinge pins and to use AN4 bolts instead, as popping the canopy in flight has never been tested (that I know of) and I decided it was all too iffy to bother with. Plus the linkage would interfere with my tight avionics placements. But, if I could replace those AN4 bolts with explosive bolts, that would give me the best of both worlds.


I know some military aircraft use explosive bolts in some applications. Is it possible to get explosive bolts anywhere, like in AN4 sizes?

thanks,
brian

[jcoloccia]

LOL....only someone from NH would think of something like this.

Currently in California but working my way back. Dang, I miss that place.

[GAHco]

Originally Posted by brian

I decided some time ago to not use the standard tipup canopy hinge pins and to use AN4 bolts instead, as popping the canopy in flight has never been tested (that I know of) and I decided it was all too iffy to bother with. Plus the linkage would interfere with my tight avionics placements. But, if I could replace those AN4 bolts with explosive bolts, that would give me the best of both worlds.


I know some military aircraft use explosive bolts in some applications. Is it possible to get explosive bolts anywhere, like in AN4 sizes?

thanks,
brian

How much money do you have? (NASA was/is the primary user)

[Ironflight]

You've actually got a good question, but the truth of the matter is that explosive bolts really aren't - bolts, that is. "Pyrotechnic separation" is usually accomplished with nuts that split, guillotine cutters (for cable bundles), primer cord which actually cuts the metal - or, in the rare case, a bolt with a weakened shank or head that is fractured. But what the general term "explosive bolt" conjurs up in the average mind really doesn't exist.

Now, if you WERE to come up with a design that could explosively separate your canopy, you'd probably spend way more than the airplane is worth (literally) doing the engineering for the one-of-a-kind device. Then you'd have to worry about always wearing nomex in the cockpit, so that if you fired it, you wouldn't ignite.

Good quesiton....but I didn't say you'd like th answer....

Paul

[AX-O]

By the way. You and your passenger are inside when those things go off. The first few times JSF did egress testing with a dummy. The dummy's head was completely destroyed. I would not want to find out that type of information the first and potentially the last time you activate those devices.

[az_gila]

Originally Posted by Ironflight

.....
Now, if you WERE to come up with a design that could explosively separate your canopy, you'd probably spend way more than the airplane is worth (literally) doing the engineering for the one-of-a-kind device. Then you'd have to worry about always wearing nomex in the cockpit, so that if you fired it, you wouldn't ignite.

Good quesiton....but I didn't say you'd like th answer....

Paul

As well as lots of discussions with the BATF....

gil in Tucson - all of our explosive devices were assembled in bunkers, even the little ones.... and the test procedures can be tricky.... The pilots didn't like it when the missiles didn't separate from the plane...

[brian]

Hmmmmm - so much for that idea. I had pictured a nice little AN4 bolt that just went *pop* enough to break it. Sounds like there's MUCH more to it than that, which I guess is why I never heard of any being for sale. On second thought, I suppose there would be little difference between one of them and a blasting cap, which you can't exactly go down to the hardware store and buy a box of. Thanks for all the feedback.
brian

[TX7A]

I wish I had a simple way that I could jettison all the wheel pants off if I were about to make a forced, off-field landing.
Seems like it may help in keeping the plane from flipping over from the pants getting hung-up in grass, weeds. etc......and roll better.

...just one of those wild thoughts I guess.

[Geico266]

When I was a purchasing agent for a phamacutial company an engineer wanted me to get a quote on a device to read pressure from the inside of a power mixing tank and send a signal to exploding bolts to blow the hatch off the side, thereby releasing pressure before the tank exploded. His estimated cost $100,000. After careful consideration I went to the hardware store and bought 6 nylon 1/4-20 bolts and handed them to him. After two weeks of study he came back and said, "That will work too." Actual cost $1.00.

[John C]

Brian, there are a number of quick disconnect pins that may work. Google quick disconnect pin, bolt, etc. I found one that is not exactly what I had in mind, but you can look around.

http://www.pleasureboatmarine.com/scp75961.html

Regards, John.