A commuter plane that crashed in a hayfield after the left engine failed should have been able to fly with only one engine, investigators say.
The search for the cause of the engine failure focused on a snapped propeller blade. A 16-inch piece of the 5-foot blade was all that remained in the left engine's propeller hub, but it was unclear if the blade broke before or during the crash.Passengers aboard the Atlantic Southeast Airlines plane said they heard a loud noise from the left engine on the Embraer 120 turboprop Monday shortly after the plane reached cruising speed. The pilot managed a crash landing about nine minutes later.
The pilot and four passengers died; 24 people survived, some with severe burns. Seven people were in critical condition Wednesday.
A team from the National Transportation Safety Board was back at the crash site Wednesday morning, picking through the wreckage piece by piece and looking for the rest of the left propeller blade, said NTSB spokesman Alan Pollock.
"If they can locate that, it would certainly tell them it came apart when it crashed. If it's not located, you might wonder if something might have happened in the air," he said.
Also missing is a gear from the gear box that linked the engine to the propellers, he said.
An Atlantic Southeast Embraer 120 that crashed in Georgia in 1991, killing former Sen. John Tower and 22 others, went down after a worn part failed in a propeller control system on the left engine.
In Monday's crash, investigators found nothing mechanically wrong with the plane's disabled left engine other than the fact that it was ripped from its mount, said John Hammerschmidt of the NTSB.