A Southwest Airlines Co. plane that skidded on its belly at New York’s LaGuardia Airport July 22, injuring nine people, hit the runway nose first before the front landing gear broke, U.S. accident investigators said.
The Boeing Co. 737-700’s nose was pointed at an angle of 3 degrees downward when it struck the runway, the U.S. National Transportation Safety Board said in an e-mailed release yesterday. Jet-powered planes are designed to touch down on the main landing gear beneath the wings, with the nose pointed upward.
That finding may indicate the accident occurred because of a hard landing rather than an equipment or maintenance failure.
“Evidence from video and other sources is consistent with the nose gear making contact with the runway before the main landing gear,” the NTSB said in the release.
The nose gear folded rearward and damaged an electronics bay, according to a July 23 statement on the agency’s website.
“We continue to participate in the NTSB investigation and are as invested as they in the final findings,” Brad Hawkins, a Southwest spokesman, said by phone. “These are not those.”
Four seconds before touchdown, as the plane neared the runway at an altitude of 32 feet (10 meters) while flying at 154 miles (248 kilometers) an hour, the nose was pointed 2 degrees upward, according to the NTSB. The investigation agency didn’t say what may have caused the nose to then tip downward.
“The landing scenario the NTSB describes from video and other sources is not in accordance with our operating procedures,” Hawkins said.
Large aircraft such as a 737 aren’t supposed to be landed on the front gear, Patrick Veillette, a corporate pilot who has written on aviation safety, said in an interview.
“The aircraft is not designed to take that kind of impact on the nose,” Veillette said.
Lifting the nose as the plane nears the ground, known as a landing flare, ensures that the main gear hits first, he said. A proper flare also slows a plane’s descent, ensuring a softer touchdown, and helps reduce speed, he said.
Landing at LaGuardia requires a firmer touchdown than at some other airports because it has relatively short runways, he said. That allows pilots to begin braking sooner so they can stop in a shorter distance.
Runway 4, where the Southwest plane touched down, is 7,000 feet long, according a U.S. Federal Aviation Administration airport chart.
The 737, the most popular airliner, skidded on the runway for about 19 seconds before stopping, according to the NTSB.
Boeing is “unable to comment on an active” inquiry, Marc Birtel, a company spokesman, said in an e-mail. “We continue to provide support to Southwest Airlines and the NTSB investigation.”
Investigators plan to interview the pilots, collect witness accounts and videos of the collapse, and review maintenance records, the NTSB said in the July 23 release.
The agency is scheduled today to begin transcribing a recording of the cockpit sounds, including comments by the pilots.
The crash forced the airport to shut down during the evening of July 22, triggering flight delays and cancellations across the U.S.