Interesting idea. The AH-64 Apache attack helicopter has a service ceiling of 20,000 feet. So also the CH-47 Chinook cargo helicopter. No flamethrower has ever been mounted on a helicopter. Too much danger of flame ingestion by the engines. But machine gun fire would be possible. The problem, of course, as the lead article pointed out, is that you can shoot one of these balloons full of holes and it will have very little effect on its buoyancy. So, I think it is a non-starter.
Interesting idea. The AH-64 Apache attack helicopter has a service ceiling of 20,000 feet. So also the CH-47 Chinook cargo helicopter. No flamethrower has ever been mounted on a helicopter. Too much danger of flame ingestion by the engines. But machine gun fire would be possible. The problem, of course, as the lead article pointed out, is that you can shoot one of these balloons full of holes and it will have very little effect on its buoyancy. So, I think it is a non-starter.
<flips table again>