On 21 September 1956, test pilot Tom Attridge was flying Grumman's new F-11F-1 Tiger. He fired a burst from his 20mm cannon while diving and accelerating. The cockpit was then struck by an outside object. Attridge immediately radioed that he was returning to base. While attempting to land, the jet lost power and crash-landed on the runway. Attridge, thankfully, escaped safely. A subsequent examination found three bullet impacts and one intact 20mm bullet in the plane. Attridge had managed to shoot his own fighter down:
How did this happen? The combination of conditions reponsible for the event was (1) the decay in projectile velocity and trajectory drop; (2) the approximate 0.5-G descent of the F11F, due in part to its nose pitching down from firing low-mounted guns; (3) alignment of the boresight line of 0° to the line of flight. With that 0.5-G dive, Attridge had flown below the trajectory of his bullets and, 11 seconds later, flew through them as their flight paths met..Link
via View From The Porch
| Photo: Military.cz
For what its worth, Wikipedia lists the plane as having a cruising speed of 900 km/h and maximum speed 1200 km/h. The 20 mm cannon has a muzzle velocity of 2600 km/h.