Listening to NPR this morning, they had a piece with an interview of an ex-drone pilot. He recounted one attack, where he states that he saw one of the combatants/targets turn his attention toward the missile because the c/t “heard” the sonic boom of the missile before the missile hit.
Huh? I thought that if something creates a sonic boom, it is going faster than the speed of sound, the sonic boom would occur after the missile hit the target. I suppose it is possible the c/t heard the launch, but is it possible he heard the boom before the missile strike?
No, you’re right, it’s not possible. I mean, maybe the target heard a previous missile that wasn’t targeted at him or something, and maybe he saw the drone out of the corner of his eye and turned, but he certainly didn’t hear a sonic boom from a missile that hit him.
If he heard the launch before the missile hit him, then the missile probably wasn’t going supersonic. Possibly he wasn’t using ‘sonic boom’ in the technical sense, but just ‘sounds like boom’
It also brings up the question as to whether the missile flies straight to the target. That is, does the drone have to be approaching the target to fire?
If the drone can site and engage a target behind it and the missile has the ability to track and turn, a sonic boom from the missile might reach a target before the missile does.
Well, the speed of sound in rock/earth is considerably faster than in air (ten times, if I’m reading this table correctly.) So I suppose that if you fire at a relatively flat trajectory, the sound of a sonic boom could hit the ground and propagate through that. Although I doubt you’d get much directionality or volume out of it.
Couldn’t the rocket go fast enough to create a sonic boom and then slow down before reaching the target? Then the sonic boom would catch up to and surpass the rocket given sufficient time.
I’m thinking, for example, the missile initially going at supersonic speeds after firing and then slowing to subsonic speeds as it guides itself to the target.
Aside from Hellfires, the other preferred projectile fired from a drone would probably be a Griffin missile. The AGM-176 is specifically intended to take out individuals or very small targets with its 13-pound warhead, minimizing “collateral damage.”
So far I am unable to find any claims as to whether it is sonic or subsonic.
I apparently heard the same NPR broadcast, and I had the same question.
I don’t expect there was much of an arc involved, as the description was of a missile fired from a drone. That probably means a Hellfire, which are almost all laser guided (some few are radar guided). So the drone would be providing laser targeting after launch and would probably need to maintain line of sight. I wouldn’t expect the flight to have much “lob” to it given the air - to - ground nature of the munition and the laser targeting, so I’m doubtful that the sound wavefront could ‘get ahead’ of the missile. But I do not know for certain.
I’ve witnessed a rather large aircraft, F-111, fly by very low and supersonic. I heard or felt nothing until the boom. However I could see a dust cloud behind the aircraft as it was flying that low.
