Tuesday, August 9, 2011

CHINOOK MAY HAVE FLOWN AT MAXIMUM CAPACITY

The downing of a CH-47 Chinook helicopter on Saturday, August 6, that claimed the lives of 38, some 60 miles southwest of Kabul, will go down as the largest loss of life for US forces during the course of the ten-year war. The bodies of the troops, including 22 members of the elite Navy SEALS, were due to arrive at Dover Air Force Base on August 9.

The Chinook transport helicopter went down during an anti-Taliban operation in the remote Tangi Valley of Wardak province, reportedly after being fired on by an insurgent rocket-propelled grenade. Seven Afghan soldiers and an Afghan interpreter were among the 38 killed. NATO says that an investigation is under way to determine the exact cause of the crash.

COMMENT: Although this incident is profoundly tragic for the victims of the crash and their survivors, it is an understatement that crashes of the Chinook are not rare. For years there have been questions concerning the aircraft's aerodynamics, particularly at high altitudes. Even though the Chinook is probably able to accommodate altitude far better than most helicopters, high altitudes and heavy payloads can be a dangerous combination that forces the Chinook to fly at the limits of its capabilities. At sea level, dense air helps create lift, but at high altitudes, heat and humidity lowers air density, causing takeoffs, climbs and hovering to reach dangerous levels. The end result is that all three environmental conditions deprive the engines of less air which produces less power and maneuverability. Although the Chinook can fly at higher altitudes far better than most helicopters, that doesn't mean that the aircraft has high maneuverability in countering ground attacks.

Another factor relative to this accident pertains to the extremely large number of special operations personnel that were aboard the aircraft, considering the high-cost of training of such operatives and the fact that they are few in number in a military theater where dependence on special ops troops is so high.