Two experienced pilots disregarded basic pre-flight safety procedures before last year’s fiery jet crash at Hanscom Field that killed seven people, federal investigators ruled Wednesday.
The National Transportation Safety Board, in a wide-ranging decision, also criticized an aircraft design that failed to prevent the pilots’ mistakes when the Gulfstream G-IV barreled off the runway on May 31, 2014. Among those killed was Lewis Katz, co-owner of The Philadelphia Inquirer.
Board members cited the workings of the corporate jet, which allowed the aircraft to reach significant speed without its equipment in a safe position for takeoff.
Robert L. Sumwalt, who sits on the NTSB, noted that aviation relies on a system of failsafes to prevent accidents.
“Clearly, we had holes in each of these layers of defense,” he said at a hearing in Washington, D.C.
The NTSB criticized the company that made the plane, along with the Federal Aviation Administration, for allowing that plane and others to operate without measures that prevent pilots from attempting to take off without disengaging the gust lock.
The crucial piece of equipment holds controls in place when a plane is parked, but can be extremely dangerous if it is in place while a plane is moving at high speeds.
But the NTSB placed the majority of the responsibility on the pilot and co-pilot on the flight, which was carrying Katz and friends home from a party. Investigators said the two neglected to check flight controls and missed an indicator that would have alerted them the gust lock was on.
Then when they began to experience problems on the runway, they attempted — unsuccessfully — to disengage the equipment rather than aborting the flight. By the time they reached the end of the runway, it was too late.
Nancy Phillips, Katz’s longtime partner, said Wednesday that she was grateful to the NTSB for its thorough investigation and careful review of the facts, painful as they are.
“What’s shattering is that the evidence shows that this was a preventable tragedy,’’ said Phillips, the Inquirer’s city editor. “My heart breaks at that — and at the loss of the love of my life. I also mourn the loss of so many of our friends. The world is diminished by their absence.”
Pilot James McDowell of Georgetown, Del., copilot Bauke “Mike” De Vries of Marlton, N.J., and flight attendant Teresa Anne Benhoff died.
In addition to Katz, the crash killed three guests aboard the plane.
Benhoff’s mother and sisters were at the hearing, according to an attorney representing Benhoff’s husband in a wrongful death suit over the crash.
Robert D. Schulte, the Maryland-based attorney working for Daniel John Benhoff, said Wednesday that the NTSB decision “offers some limited closure for the family. . . . They want answers, rightly so, about why their sister and daughter are no longer with them.”
The conclusions of the NTSB report can’t be used in litigation.
Schulte said it is a delicate matter to assign blame for such a crash. He said he found the report helpful in pointing out the many factors that come into play — including regulation, mechanics, and sometimes, human error.
“These mistakes don’t happen in a vacuum,” Schulte said. “They occur in a context.”
Attempts to reach relatives of McDowell and De Vries were unsuccessful.
In approving a final report on the crash, which will be issued in coming weeks, the NTSB agreed on a probable cause, described 17 findings, issued five recommendations, and released a safety alert.
Among recommendations are improvements to Gulfstream planes like the one that crashed at Hanscom, in Bedford. Investigators want to make sure in the future, pilots will get better signals to alert them when the gust lock is on.
Officials with Gulfstream emphasized Wednesday that the planes have a good safety record. However, they said they are working to eliminate problems like the one experienced in the crash.
The company said it had told operators to use proper pre-flight and takeoff procedures, and was working with the FAA on a plan to modify planes built between 1987 and 2003, which could have similar issues related to the gust lock.
The NTSB on Wednesday also offered a critique of the emergency response to the crash. The plane wound up in a nearby ravine and burst into flames.
Although the board emphasized that nothing could have saved the lives of those aboard, it pointed out that the efforts were disrupted when firefighters used up their water supply. Because nobody had left a hose by a nearby hydrant, responders were without water for several minutes.
Officials with the Massachusetts Port Authority, which oversees Hanscom, have made several changes in the meantime — including adding a deputy fire chief to oversee operations there and improving maps of the surrounding area to speed future response.
The pilots of the Gulfstream were experienced and had flown the plane together many times, but records showed almost never performed basic safety checks.
T. Bella Dinh-Zarr, NTSB vice chairwoman, said she hopes the report will help prevent future tragedies.