Aug. 7 (Bloomberg) -- The captain of a Southwest Airlines Co. plane took the controls from the first officer shortly before it slammed down nose-first at New York’s LaGuardia Airport, breaking the landing gear and skidding down the runway.
The U.S. National Transportation Safety Board in an e-mailed release yesterday said it hasn’t found any evidence of a mechanical failure on the plane during the July 22 accident.
The absence of an equipment malfunction combined with the switch of command a few seconds before touchdown points the investigation toward the actions of the crew. The NTSB hasn’t concluded the cause of the crash.
Nine people received minor injuries in the accident.
Why the command changed between the first officer and captain “is what we hope to understand as our investigation with the NTSB continues,” Brad Hawkins, a spokesman for Dallas-based Southwest, said in an interview.
“Our Southwest pilots manual and training includes scenarios which cover how to handle change of control of aircraft, including on final approach,” Hawkins said.
A change in control may occur for reasons that range from the routine to a response to an emergency, according to NTSB accident records. No reason was given for the switch, which occurred after the plane went below 400 feet in altitude.
The pilots of Flight 345, which originated in Nashville, Tennessee, are on leave during the investigation in accordance with Southwest’s normal procedures, Hawkins said.
The Boeing Co. 737-700 landed with its nose pointed three degrees downward, hitting the runway with its nose gear first instead of the larger main landing wheels located beneath the wings, the NTSB said in a July 25 release. The forward gear broke, snapping rearward and damaging an electronics bay.
“A preliminary examination of the nose gear indicated that it failed due to stress overload,” investigators said in the release yesterday.
The nose-wheel landing was “not in accordance with our operating procedures,” Hawkins said in an interview on July 25.
While a change in command shortly before landing is unusual, it shouldn’t by itself cause an accident, John Cox, a former pilot and president of Safety Operating Systems, a Washington consulting firm, said in an interview.
“It raises more questions than it answers,” Cox said.
Airlines train pilots how to switch command in the cockpit and how to communicate during unusual events. Investigators will attempt to determine how the pilots performed on these tasks, he said.
The NTSB also will pay close attention to how well the pilots lined up the plane with the runway, he said. In order to prevent landing accidents, pilots are trained to abort a touchdown if a plane is off its target speed and altitude.
The captain has been a pilot at Southwest for almost 13 years, six of which as a captain, according to the release. The pilot, who wasn’t identified, had more than 12,000 flight hours, including 7,900 in the 737.
The co-pilot, who has been with the airline for about 18 months, had about 5,200 flight hours, including 1,100 in the 737, according to the NTSB, which issued its second update on the accident yesterday.
While the first officer had experience flying to LaGuardia, including six flights there this year, it was the captain’s second landing there. On the previous touchdown, he had been monitoring another co-pilot instead of commanding the plane, according to the NTSB.
The crew told investigators they encountered a wind shift as they approached the runway at LaGuardia, according to the release. Below 1,000 feet altitude, they said they had a tailwind of 13 miles (21 kilometers) an hour. On the ground, the wind was at the same speed in the opposite direction, they said.
The crash forced the airport to shut down during the evening of July 22, triggering flight delays and cancellations across the U.S.