" />

Footage of the wreckage of the stealth helicopter left behind at Osama bin Laden's compound by US forces has prompted conjecture that the aircraft is a secret, highly-modified version of the military's iconic Black Hawk.

The damaged helicopter, which commandos blew up at the scene, is possibly a HH-60G Pave Hawk modified to reduce rotor noise and undetectable by radar or infrared. The Pentagon has declined to comment.

The aircraft was one of two helicopters that transported the Navy SEALS who carried out the raid from Bagram Air Base in Afghanistan to the Abbottabad, Pakistan compound.

Al Jazeera speaks to Robert Densmore, a former US Naval Flight officer, about the vital role of the helicopters in the mission and what caused one of them to crash.

Source: Al Jazeera and agencies