BEDFORD — The Gulfstream IV jet that crashed at Hanscom Field Saturday night, killing seven people, reached a speed of 190 miles per hour before slowing down during its attempted takeoff and hurtling into a gully, air crash investigators said Tuesday.
Information from the plane’s flight data recorder indicated that the jet’s thrust reversers had been turned on and that brake pressures were rising, Luke Schiada, the lead investigator for the National Transportation Safety Board, said at the scene.
The scenario described by the investigator suggested that the pilots were trying to abort the takeoff, one veteran pilot said. Thrust reversers are typically used to slow planes down by diverting jet exhaust to the front, rather than the back, as in normal operation.
“The thrust reversers deployed and the wheel brake pressures rose as the airplane decelerated,” Schiada said. “We’re also observing tire marks on the runway.”
Schiada declined to say outright that the pilots were trying to stop the plane, saying: “We’re not interpreting the information that the thrust reversers were deployed. . . . I don’t want to interpret what the actions are.”
He also did not give any indication as to why the crew might have been trying to stop the plane.
“We’re not going to speculate,” Schiada said.
However, Bruce Landsberg, an experienced pilot and president of the Aircraft Owners and Pilots Association Foundation in Frederick, Md., said it sounded as though the pilots had decided to halt the plane.
It appeared, he said, that “the crew, for whatever reason, decided they needed to reject the takeoff, and they ran out of runway before they got the airplane stopped.”
As it raced down the runway, the airplane reached a maximum speed of about 165 knots, or about 190 miles per hour, Schiada said. But the flight data recorder indicated it never left the ground.
The flight recording ends about seven seconds after the thrust reversers were deployed. At that point, the plane had slowed to about 100 knots, or 115 miles per hour, Schiada said.
In addition, the jet’s cockpit voice recorder captured various callouts in the cockpit, including “rotate,” as the plane sped down the runway. That is typically the signal from the copilot to the pilot to pull back on the control yoke and bring the nose up, Landsberg said.
“After the rotate callout, the [cockpit voice recorder] captured comments concerning aircraft control,” Schiada said.
The NTSB investigator would not elaborate on what those comments were.
Schiada said the cockpit voice recording ultimately ended with the sound of impact.
On Monday, investigators recovered the two recorders. Schiada stressed that the analysis of the data from the recorders was preliminary “and we still have a great deal of work to do.”
He said both devices had captured hours of data, including the final 49 seconds of the flight when the plane began to roll down the runway and then crashed.
According to Schiada, the cockpit voice recorder had captured about two hours of “good to excellent” audio, while the flight data recorder had captured about 41 hours of data. Both devices were made by L-3 Communications.
The plane was taking off at about 9:40 p.m. Saturday, heading to Atlantic City, N.J., with Lewis Katz, 72, co-owner of the Philadelphia Inquirer, aboard, as well as three of his guests and a three-member crew.
NTSB officials have said the plane left the end of the official runway, which is 7,011 feet long, traveled another 1,000 feet over extra paved surface, and then another 819 feet on the grass before hurtling into a gully at the edge of the airport, where it was consumed by flames.
Along the way, the Gulfstream IV destroyed an antenna used to guide planes on instrument landing approaches, as well as a chain-link fence, investigators have said.
The crew members aboard the plane were: pilot James McDowell, 51, of Georgetown, Del.; copilot Bauke “Mike” De Vries, 45, of Marlton, N.J.; and flight attendant Teresa Ann Benhoff, 48, of Easton, Md.
Katz’s guests were 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.
Investigators expect to remain at the crash site gathering information through the end of the week, Schiada said. A preliminary report on the crash is expected to be issued by the agency next week.
In the meantime, Schiada said, investigators will continue reviewing information about the flight crew, witness statements, and surveillance footage, among other evidence. The recorders have been forwarded to NTSB labs in Washington, D.C.
Schiada said that investigators had not found any problems with the plane’s brakes or tires and that authorities were also reviewing the configuration of the flaps at takeoff.
Investigators have not had a chance to examine the engines yet, he said.
Bruce “Buck” Rodger, president of the Los Angeles-based Aero Consulting Experts, said a number of factors may have contributed to the crash.
“There’s always a buildup to a reason why an airplane has crashed,” Rodger said. “There will be more than one event here, absolutely.”