Kabul: US military investigators have concluded that the Chinook helicopter crash in Afghanistan that killed 30 US troops in August was caused by an insurgent who fired a rocket-propelled grenade that struck the rear rotor of the aircraft.
It was deadliest single incident for US forces in the decade-long war.
The August 06 crash came amid rising fears that the country is far from stable even though US and NATO forces have begun to leave Afghanistan. US military officials have tried to counter those fears, saying that while the downing of the Chinook was a tragic setback, one crash will not determine the course of the war.
An official investigation report, issued on Wednesday by the US Central Command, said that after the grenade hit the rotor, the helicopter spun violently and then the main fuselage dropped vertically into a dry creek bed. The report said the copter was immediately engulfed in flames and the fire triggered several explosions of fuel and munitions.
No one survived the crash in Tangi Valley of Wardak province, about 60 miles (97 kilometres) southwest of Kabul.
Among those killed were 17 members of the elite Navy SEALs, five Naval Special Warfare personnel who support the SEALs, three Air Force Special Operations personnel, an Army helicopter crew of five, seven Afghan commandos and an Afghan interpreter.
The report said that while final autopsy reports were still being reviewed, it`s believed that all 38 persons on board died rapidly after the crash.
Investigators found no wrongdoing by personnel involved in the mission. The decision to transport the entire immediate reaction force in one helicopter was "tactically sound" to mitigate aircraft exposure to ground fire, the report said.
However, it said the special operations task force commander did not reallocate the intelligence, surveillance and reconnaissance aircraft to ensure ongoing surveillance coverage for both missions. While this was not the cause of the shoot-down or crash, the report said the issue should be addressed in similar missions in the future.
The report dismissed speculation that the troops aboard the helicopter were lured into the valley by insurgents with advance knowledge of the landing site.
"The shoot down was not the result of a baited ambush, but rather the result of the enemy being at a heightened state of alert due to three and one half hours of ongoing coalition air operations concentrated over the northwestern portion of the Tangi Valley," the report said.