Aerostat Accident Explained

Delayed response to an approaching thunderstorm caused the loss of a tethered blimp at Lajas, Puerto Rico, last August, according to the findings of Air Combat Command’s accident investigation board. Caught by gusting winds, the tethered aerostat radar system dragged its securing winch truck into an embankment, partially due to the ground crew incorrectly placing the vehicle’s chock blocks, states the AIB report (caution, large-sized file). Grounded against the embankment, the blimp’s tether was drawn taut against a safety cable. Severed by the resulting friction, the blimp slipped its mooring, promptly climbed to above 7,000 feet in altitude, and ruptured. The rig spilled some 71 gallons of fuel, but caused neither injury nor property damage. Total loss of equipment is estimated at $8.1 million, not including the cost of spill clean-up and site remediation. (Langley release)