By lex, on May 7th, 2011
New details are emerging about the loss of a SOAR Ghosthawk in the bin Laden raid:
A United Technologies Corp. Black Hawk helicopter carrying U.S. Navy SEALs to Osama Bin Laden’s hideout was downed by an air vortex caused by unexpectedly warm air and the effect of a high wall surrounding the compound, not mechanical failure or gunfire, according to U.S. officials and a lawmaker.
The Army pilot from the service’s most elite aviation unit executed a hard but controlled landing — clipping a corner wall — after the chopper lost lift. The 12 heavily armed SEALs exited the aircraft unharmed.
And then went about their mission. Fly a long range assault, at low altitude, at night, crash, egress and execute.
A good job by the pilot too, all things considered:
The helicopter that crash-landed was supposed to hover over the compound’s courtyard so that the SEALS would rappel, or “fast rope,” to the ground, Panetta said.
According to two U.S. officials, who praised the skill of the pilot, the chopper lost the lift necessary to hover because it entered a “vortex” condition. At least two factors were at play — hotter than expected air temperature and the compound’s 18-foot-high walls, they said.
The wall blocked rotor blade downwash from moving down and away as it normally would. This caused disturbed airflow to move in a circular, upward and then downward path back through the top of the rotor, causing insufficient lift for the aircraft.
Any landing you can assault away from.