Loud crackers were once used to drive birds downwind, specially before a take-off, and even more especially before a VIP departure....perhaps they still are.
So one day HRH His Ludship Charles, Prince of Wales, elected to travel to an engagement by BAe 146/Helicopter, transferring on our specially polished apron, rather than travel for 2 hours mixed up with hoi polloi in a train. This would happen twice, on the way there and on the way back.
The outward transfer went smoothly, but he completely blanked the firecrew party waiting to save his life if the helo caught fire with him in it.
So on the way back, as he walked between the two aircraft, they let off a fusillade of crackers about 100m from the helo, just to ensure there were no birds around. This was their patriotic duty, as the RFFS were in charge of anti-bird systems.
SB and protection officers went promptly into full war mode, weapons drawn, and HRH didn't quite succeed in not looking nervous, although he did try.
Never cross the stalwarts of the RFFS is a lesson we all have to learn.