Bob Sauer said that his 50-foot cedar trees had acted on the same scientific principle as an airbag, disrupting the door plug’s fall in an act known in physics as impulse.
Boeing and the Federal Aviation Administration issued technical instructions to airlines two days after a part of a plane was blown out near Portland, Ore.
Alaska Airlines restricted the use of the plane, which lost part of its fuselage on Friday, because of a warning light that went off on previous flights, an official said.