Investigators believe ground checks were incorrectly carried out before an incident in which an Aeroflot Sukhoi Superjet 100 sustained engine cowl damage.
The aircraft had been operating from Moscow Sheremetyevo as flight SU1808 to Odessa early on 14 February.
It departed runway 25L but returned after “failure of one of the cowlings”, says Sukhoi’s civil aircraft division. The aircraft landed safely.
The airframer says a preliminary investigation shows that “incorrect execution” of procedures during the pre-flight inspection led to the incident.
Sukhoi Superjets are fitted with PowerJet SaM146 engines. Images purportedly taken from the cabin during the incident indicate that the left-hand engine’s cowls were completely torn off.