The National Transportation Safety Board is expected next week to determine — officially — what caused the deaths of seven passengers, including Philly philanthropist Lewis Katz, when the jet they were in crashed.
Katz, his two pilots, a flight attendant and three fellow passengers were killed when Katz' business jet, Gulfstream G-IV, overran a runway at Hanscom Field in Bedford, Mass.
The plane came to rest in a ravine and burst into flames. No one survived the May 31, 2014 flight which was headed to Atlantic City, N.J.
In a preliminary report, NTSB investigators pointed to the plane's gust lock system as a probable factor in the cause of the crash. It's designed to keep parked airplanes steady. The lock was still engaged when the pilots tried to take off which means they didn't have full use of all the parts needed to lift the plane off the ground.
Pilots would have discovered the system was locked during routine systems checks before takeoff, but documents released in April indicate the pilots rarely performed those checks.
After the crash, Gulfstream reported a problem with a fail-safe system allows planes to reach high speeds on the runway even if they're unable to take off. That discovery led to a design change.
The company contends pilot error caused the crash.