Boeing’s (BA) long, difficult year kicked off with a 737 Max door plug blowout, and now a new part is drawing scrutiny from federal investigators. Reuters reports that the Federal Aviation Administration is looking into problems with the planes’ engines after a pair of bird strikes last year aboard a pair of Southwest Airlines (LUV) flights.

The FAA is weighing new takeoff instructions for Boeing 737 MAX pilots to avoid a risk of smoke in the cabin or flight deck if an engine is hit by a bird.