It was the first jet fighter to shoot itself down. I stumbled across that nugget of information after cruising Wikipedia looking at the A-7 that F86Sabre posted last night.
The F-11 Tiger is noted for being the first jet aircraft to shoot itself down. On 21 September 1956, during a test-firing of its 20 mm (.79 in) cannons, pilot Tom Attridge fired two bursts midway through a shallow dive. As the velocity and trajectory of the cannon rounds decayed, they ultimately crossed paths with the Tiger as it continued its descent, disabling it and forcing Attridge to crash-land the aircraft; he survived.