The company that made the private jet plane that crashed last month at Hanscom Field in Bedford, killing all seven people on board, is urging flight crews to perform certain maintenance checks before takeoff that federal officials have tied to the fatal accident.
In a letter dated Friday, the Gulfstream company urged crews to “ensure the gust lock is off prior to staring engines (not applicable for G650).”
The company also urged crews to “check flight controls for freedom and correct movement prior to taxi/takeoff” and to “confirm the elevators are free during the takeoff roll.”
Peter Knudson — a spokesman for the National Transportation Safety Board, which is investigating the crash — confirmed in a phone interview that the gust lock is “germane” to the review of the crash. He did not elaborate.
The gust lock function holds flight controls in place when an aircraft is parked, so the controls are not affected by high winds or other movements, aviation experts said. But if gust locks are on during takeoff, there can be problems.
“That’s always been on the checklist” of things to review before takeoff, said Gene Allen, a longtime Gulfstream pilot.
According to a preliminary report released by the NTSB, the pilots aboard the corporate jet that crashed on May 31 at Hanscom Field may have failed to conduct a preflight check and possibly attempted to take off with the plane’s lift controls in a locked position.
The Gulfstream IV jet reached a speed of nearly 190 miles per hour on the runway, but never became airborne, according to the report. Instead, the jet left the runway, rolled onto the grass, struck an antenna, and burst through a chain-link fence before sliding into a gully, where it erupted into flames, the report stated.
The federal report also raised a question about whether the gust lock was engaged when the pilots attempted to take off. The device keeps the ailerons and rudders in a neutral position and the elevators in a down position to prevent wind gusts from damaging the aircraft when it is stationary, the NTSB report said.
Investigators found the position of the elevators at the back of the plane was consistent with the gust lock being on, according to information from the flight data recorder. But authorities discovered that the lock was off when they went through the jet’s wreckage, the report said.
A Gulfstream spokeswoman did not return a call seeking comment on Monday.
Elevators, located on the rear wings of the plane, are crucial to lifting the plane’s nose to take flight. If the elevators were in the down position, the plane would not take off.
The crash victims included Philadelphia Inquirer co-owner and philanthropist Lewis Katz; pilot James McDowell, 61, of Georgetown, Del.; copilot Bauke “Michael” De Vries, 45, of Marlton, N.J.; Anne Leeds, a retired preschool teacher from Longport, N.J.; Marcella Dalsey, executive director of the Drew A. Katz Foundation; and Susan K. Asbell, who served with Dalsey on the strategic planning committee of the Boys & Girls Club of Camden County, N.J.
Bruce Landsberg, president of the Aircraft Owners and Pilots Association Foundation in Frederick, Md., said Monday that he had to reserve judgment until the final report on the crash comes out. The NTSB could take up to a year to release its final report.
“These [theories] are all speculation, until we know more than we do now,” said Landsberg.
Last week, he discussed the problems an engaged gust lock could cause.
“The pilots should have disengaged the gust lock right when they started the engine; it’s not clear whether they did or not,” Landsberg told the Globe last week. “It would be bad to try to take off with that engaged, because the flight controls would be immovable.”