Monday, February 6, 2017

NTSB concludes tug speed caused Southwest nose gear collapse

The US National Transportation Safety Board (NTSB) said in a newly released report that “excessive speed” by a tug driver caused the nose gear of a Southwest Airlines Boeing 737-300 to collapse upon pushback from the gate at the Baltimore-Washington International Airport on the night of Aug. 4, 2016.

While none of the six crewmembers or 129 passengers was injured, the aircraft was “substantially” damaged when the nose gear collapsed in the forward direction, damaging the gear structure, the nose gear well and the forward bulkhead, according to the NTSB’s final report on the incident.

Investigators used an airport surveillance video to calculate that the tug was pushing the aircraft back at approximately 7 mph, a speed that would have required the tug to be operating in second gear or higher. “The airline general operating manual specifies that pushback must be conducted in low or first gear, and at a walking speed,” the NTSB said. The specifications for the GT-35 tow tractor state that first gear is limited to a maximum speed of 2.5 mph (or approximately 3.6 ft. per second).

According to the pilots, the aircraft bounced several times during the pushback before the gear collapsed and the nose fell.

The tug driver said he had tried to slow down the pushback, having started too fast, but applying the tug brakes did not slow down the aircraft. Instead, the braking caused it to “start to rock and bounce,” he said. “As I finally got the (tug) to slow up, the plane then had too much momentum and pulled away from me,” the tug driver said in a statement to the NTSB. “The tow bar pulled the nose gear off the plane.”

(John Croft - ATWOnline News)

No comments: