Preliminary information from Italian investigators suggests the ATR 72-500 involved in a landing accident at Rome had touched down initially on its nose-gear.
French investigation authority BEA, which has disclosed the information, says the aircraft "suddenly lost altitude" just before touchdown at Rome Fiumicino on 2 February.
The flight from Pisa was being operated on behalf of Alitalia by Romanian carrier Carpatair.
BEA says the aircraft struck the runway with its nose-gear and bounced three times before sliding off the runway on its fuselage underside.
Fiumicino had been subjected to gusting winds at the time. All 50 occupants survived the accident but the turboprop sustained heavy damage.