The plane that crashed during takeoff out of Bangor earlier this year sat on the ground beforehand for nearly a half hour in an ice storm.
Since federal transportation officials said Friday they’ve determined nothing was mechanically wrong with the plane, suspicion now turns to wing icing.
The National Transportation Board’s preliminary findings show that the Bombardier Challenger 650 sat on the tarmac for roughly 24 minutes after being de-iced before it began its takeoff roll.
The plane should have waited no more than nine minutes from when the deicing began before taking off in those cold and snowy conditions, according to Federal Aviation Administration guidelines.
A preliminary review of the cockpit voice recorder revealed the flight crew discussed de-icing holdover times as the aircraft taxied to the runway.
The pilot commented that it was “standard” to have a 14-to-18-minute lag time between de-icing and takeoff.
But he also was heard telling the copilot that if the wait were more than a half hour they would be forced to return to the ramp to de-ice again.
Aviation safety consultant and former international captain John Cox told The Associated Press that comment “makes me wonder if they actually ran the time” because the guidelines make it clear they didn’t have that much time.”
The plane was deiced at 7:20 p.m. and didn’t take to the air until 7:44 p.m.
Records show they were nearing or had already passed a critical cutoff that would have made takeoff precarious.
But complicating that formula was what at least one independent analyst speculated was a perfect storm.
Steve Scheibner, a retired pilot from a major carrier, has said he believes the plane probably was in the midst of an ice-pellet storm.
Worse, the Challenger is known to be especially susceptible to wing icing.
A final crash analysis may not be completed for another two years, federal officials said.
The plane that crashed was on a refueling stopover at Bangor International Airport on its way to France from Texas.
