WASHINGTON - Federal safety officials Wednesday blamed pilot error and a faulty fail-safe system for the May 2014 jet crash that killed former Inquirer co-owner Lewis Katz and six others.

National Transportation Safety Board member Robert Sumwalt III said during a hearing that the review found "holes in each layer of defense" that led to the fiery crash.

The veteran flight crew failed to make a complete flight-control check - a failure found in 98 percent of their previous 175 takeoffs - and did not perform checks at all in 90 percent of their flights.

Investigators termed this, "intentional, habitual non-compliance with standard operating procedures."

As a result, the crew did not realize that the craft's elevators were locked in the fatal flight and the plane could not leave the ground. Once the pilots realized the jet's elevators were immobilized, they had 11 seconds before takeoff could have been safely aborted, NTSB officials testified.

Blame was also placed on the design of the aircraft, a $30 million a Gulfstream IV, which "did not provide unmistakable warning" that the plane could not take off safely, as required by Federal Aviation Administration rules.

The FAA, itself, came under criticism, for not catching the flaw in the Gulfstream's fail-safe system.

Speaking about pilot error, Sumwalt said, "We're talking about things that people didn't do that they should have done. We need to take a very hard look at these areas so that we can learn from them so that we can keep them from happening again, and that's exactly why we are here ..."

In the May 31, 2014 accident, the jet never left the ground during the fatal takeoff roll. Instead, the aircraft hurtled beyond the runway at Hanscom Field in Bedford, Mass., hitting a tower and ground antennae, then plunging into a gully, where it burst into flames.

NTSB investigators found those structures were not designed to snap away when struck, which likely contributed to damage done to the aircraft.

The crash was survivable, NTSB investigators said Wednesday. But a fire began almost instantly, blocking exits over the wing.

In previous reports, the NTSB has released data showing that the elevators - which are fixed to the jet's tail and control lift - never moved during the takeoff roll. The reports also showed that the experienced crew, two pilots who had worked for Katz for years, rarely performed the required preflight checks that would have revealed the immobilized elevators.

Experts focused during the investigation on the "gust-lock system" as the reason for the locked elevator. Pilots use this system to secure the elevators when a plane is parked, to protect the aircraft being knocked around by blasts of wind. In the case of the Katz jet, the pilots apparently failed to unlock the system before attempting the deadly takeoff.

The agency's previous report also spotlighted another key issue beyond the apparent pilot error: how the plane was able to reach such a high ground speed - 187 miles per hour - even though the gust locks had a fail-safe system.

That feature was supposed to dramatically limit the plane's ground speed if the elevators were locked. But the expert reports, including a postcrash analysis by Gulfstream, showed that it did not work as intended.

The NTSB found fault with the FAA on Wednesday, finding that the agency relied "solely" on reviews of engineering drawings to certify the key fail-safe feature on the Gulfstream - which failed.

A finding proposed by Sumwalt stated the "FAA missed the opportunity to detect the inadequate design of the gust-lock system."

Additionally, the board member criticized the FAA for needing up to a year to ensure the safety of the remaining Gulfstream IVs in service.

"There is something badly broken in the FAA if it takes six to 12 months to come out with that fix," he said.

An FAA spokesman explained Wednesday that the wait is due in large part to the rule-making process the agency has to follow. Because this was the first accident of this type in the Gulfstream's 30-year history, the FAA can't issue an emergency directive, and has to go through the normal public review process, said Les Dorr, a spokesman for the flight administration.

A Gulfstream spokeswoman expressed condolences Wednesday for the families of those killed and said the company is working on a gust-lock fix that will be rolled out to more than 500 affected jets, though she would not commit to a date when that will be complete. The new safety mechanism is undergoing flight test certification with the FAA, said the spokeswoman, Heidi Fedak.

"The G-IV fleet has an outstanding safety record with more than 500 aircraft accumulating 4.2 million flight hours over 25 years," Fedak said. "Safety is a top priority at Gulfstream, we have twice notified our operators about the importance of performing pre-flight and take off checks, and we are actively working with the FAA to modify the gust-lock interlock."

The company has conceded in public filings that the lock did not work as intended and has issued two letters to operators warning them of that flaw, while stressing the importance of pre-flight checks, she noted.

The accident killed Katz, who was 72, just four days after he had won ownership of The Inquirer, the Philadelphia Daily News, and Philly.com at auction. Following his death, his son sold his share of the company.

After making a fortune in law and business, the Camden-born Katz became a big charitable giver, pledging millions to Temple University's medical school, Dickinson Law School, and other beneficiaries. He died in the middle of a charitable trip.

The crew that day, highly experienced on that plane, was pilot James P. McDowell, 61, who had 18,500 hours in the air, and copilot Bauke "Mike" De Vries, 45, who had 11,250 hours.

On the day of the crash, they and flight attendant Teresa Benhoff, 45, took off at 1:25 p.m. from the plane's base at New Castle County Airport near Wilmington for an eight-minute hop to Atlantic City.

There, Katz and three passengers - friends and associates Susan K. Asbell, 68; Marcella M. Dalsey, 59; and Anne B. Leeds, 74 - boarded and the jet took off at 2:56 p.m. for a 48-minute flight to Hanscom Field in Massachusetts, outside Boston.

While the crew stayed behind with the aircraft, the group went to a fund-raiser for an education nonprofit organization at the home of the historian Doris Kearns Goodwin. Upon their return to Hanscom, the plane sought to take off but never got airborne.