Investigators are probing the loss of a winglet from an Embraer 175, apparently during turbulent conditions while carrying out a domestic US service.
The aircraft (N233NN) was being operated by American Airlines’ regional division Envoy Air, and was en route from Charleston to Dallas on 3 May.
According to a preliminary US FAA statement, the aircraft encountered “moderate to severe turbulence” and landed at Birmingham, Alabama.
Air traffic control communications show the arrival of flight AA3729 to runway 24 was treated as an emergency, with vehicles positioned to respond as a precaution, and a runway sweep conducted after landing.
“Post-flight inspection revealed a piece of right winglet missing,” the regulator states.
None of the occupants was injured but the full extent of damage to the aircraft has yet to be determined.
American Airlines took delivery of the aircraft in mid-2016.