Still, Knudson said an issue under investigation was whether the flaps failed to respond properly to cockpit controls.
In briefings at the crash site in Bedford, Mass., the NTSB said Tuesday that Katz's crew reversed the jet's thrust and applied the brakes even though the plane had reached what would normally be considered the takeoff point Saturday night.
The Gulfstream jet rolled off the runway and onto the grass before striking an antenna and a fence, coming to rest in a gully as it burst into flames. It left skid marks on the runway.
The NTSB's interest in the flight-control system was first reported Wednesday by the Wall Street Journal, which cited an unnamed source.
The flaps on a plane's tail, known as elevators to distinguish them from flaps on the wings, are key to takeoffs. When pilots pull on the yoke at takeoff, that instructs the elevators to lift. This drives the tail down and the nose up.
"If you can't point that nose, you're not going to get airborne," said Edward Carter, a veteran commercial pilot.
If the elevators failed, Carter said, the pilots might have had no choice but to try to bring the plane to a halt.
"If you pull back and nothing happens, what else are you going to do?" he said.
The NTSB has said that during the attempted takeoff, the pilots, as part of their standard verbal checklist, noted that they had reached the point where they needed to pull up the nose.
But after that, NTSB investigator Luke Schiada said Tuesday, the voice recorder in the cockpit "captured comments concerning aircraft control."
Neither he nor Knudson would elaborate on what the pilots said.
Among Katz's traveling companions was Anne B. Leeds, 74, a retired schoolteacher and neighbor of Katz's in Longport, N.J.
Also on the plane were Marcella M. Dalsey, 59, executive director of the Drew A. Katz Foundation - named after Katz's son - and Susan K. Asbell, 68, of Cherry Hill, a member of the planning committee of the Boys and Girls Club of Camden County.
The crew included James McDowell, 51, of Georgetown, Del.; Bauke de Vries, 45, of Marlton; and Teresa Ann Benhoff, 48, of Easton, Md.