sikorsky hh-60g pave hawk helicopter (92-26466)

SIKORSKY HH-60G PAVE HAWK (REGISTRATION: 92-26466)
The HH-60G helicopter (92-6466), assigned to the 332nd Air Expeditionary Wing (AEW), and operating within the USCENTCOM AOR, crashed in an uninhabited desert area of Iraq. Four flight crew members and three members of the Guardian Angel team were fatally injured in the mishap. The helicopter was destroyed upon impact, there were no other injuries or fatalities, and there was no damage to private property.

The mishap formation consisted of two HH-60G helicopters, with 92-6466 operating as the lead aircraft and the mishap wingman as the trail aircraft. The assigned mission was to preposition the formation to a helicopter landing zone (HLZ) closer to the vicinity of ground operations.

The flight plan for the pre-position mission was a near direct path from the base of departure to the intended HLZ with an air refueling control point between the origin and destination points.

A more extensive route of flight was loaded to the navigation system for potential follow on mission taskings, but it was not to be utilized on this mission. The loaded navigation route continued north to points beyond the intended HLZ. Night illumination for the flight was low.

The formation departed the base at approximately1800Z. The flight up to air refueling was uneventful, but refueling operations concluded later than planned. While conducting normal crew duties, the formation erroneously overflew the intended HLZ and descended to low altitude. As the mishap copilot turned left to avoid a tower, a blade on the main rotor assembly struck the second of four 3/8 inch galvanized steel cables horizontally spanning two 341-foot towers. The cable tangled around the main rotor assembly resulting in catastrophic damage, rendering the aircraft un-flyable. The helicopter impacted the ground at approximately 1840Z. An extensive rescue operation was immediately conducted.

The Accident Investigation Board (AIB) president found by a preponderance of evidence the cause of the mishap was the result of: the mishap pilot misinterpreting aircraft navigation displays, causing the formation to descend into an unplanned location and strike a 3/8 inch diameter galvanized steel cable strung horizontally between two 341 foot high towers. The AIB president also found by a preponderance of evidence that three factors substantially contributed to the mishap:
(1) mission planning created a route of flight enabling navigation beyond the intended HLZ;
(2) a breakdown in crew resource management within the MC and between the MF failed to sufficiently detect and effectively communicate the navigation error; and
(3) low illumination conditions present rendered night vision goggles insufficient to detect the cables.

Source : https://aviation-safety.net/wikibase/207646