By Joe Brandt

The plane crash that killed Temple trustee and Philadelphia Inquirer owner Lewis Katz on May 31 may have been caused by an override of the jet’s fail-safe system, according to the Inquirer.

The Inquirer obtained a copy of a letter dated Aug. 18 which Gulfstream Aerospace Corp. sent to pilots and owners of its jets.

The letter cautioned that Gulfstream fail-safe systems, which normally limit the plane to taxi speed while the gust lock is engaged, can be overridden if “proper [tail flap] unlock procedures are not followed.”

The movable tail and wing flaps are a crucial part of a plane’s takeoff, providing lift, but many planes have gust-lock systems to hold the flaps in place and protect them from potentially damaging wind while the plane is parked.

In June, investigators from the National Transportation Safety Board found through analysis of the  flight data recorder in Katz’s plane that no pre-flight control check was performed and that “[tail and wing flap] position during the taxi and takeoff was consistent with its position if the gust lock was engaged,” according to an NTSB report.

The Inquirer article, posted online August 20, quoted from Massachusetts Institute of Technology aeronautics and astronautics professor John Hansman Jr.

Hansman said the pilots should have turned off the gust-lock and then started the engines, but instead started the engines before disengaging the lock, overriding the fail-safe system and allowing the plane to reach greater speeds. The plane reached about 190 mph before it crashed.

Additionally, a professional pilot of Gulfstream jets, Steven M. Janos, told the Inquirer: “[m]y understanding is that if you start the engine, you will not be able to release the gust lock.”

Katz’s plane crashed and burst into flames at Hanscom Field near Boston, Mass. after he attended a fundraising event at the house of author and historian Doris Kearns Goodwin.

Four days earlier, he had won control of the Inquirer, the Philadelphia Daily News, and philly.com with fellow Temple trustee and business partner H.F. “Gerry” Lenfest.

The three passengers and three crew members on board died in the crash, along with Katz.

Joe Brandt can be reached at jbrandt@temple.edu or on Twitter @JBrandt_TU.