[kcrazorbackfan]

Inquiring minds want to know - how low is record low altitude?

Per FAR regulation Sec. 91-119, the definition from Wikipedia is - In aviation (particularly in air navigation), lowest safe altitude (LSALT) is an altitude that is at least 1,000 feet above any obstacle or terrain within a defined safety buffer region around a particular route that a pilot might fly. The safety buffer allows for errors in the air by including an additional area that a pilot might stray into by flying off track. By flying at or above this altitude a pilot complies with terrain clearance requirements on that particular flight leg.

Were there 2 different groups of aircraft? Some reports were of A-10 Warthogs (which cannot sweep back the wings); other reports were of aircraft with swept back wings. Warthogs are fixed-wing tank killing machines.