I once worked with a Belgian Air Force Alpha Jet pilot who was grounded for a while for low flying.
He was part of an exercise raid on a copse which was hiding an army headquarters. Their comms masts were 27 feet high with a 1 metre calibrated rod antenna mounted on the top. The chaps who set it up reckoned the mast and antenna stuck up just over 4 feet above the tree canopy.
He over flew the site and hit the mast with his wing chopping it an inch or so above the tip of the mast. Given the geometry of the Alpha jet (it's wing is set high on the fuselarge) it meant his aircraft was flying flat out through the canopy of the trees with their branches passing either side of his cockpit.
