Moscow Sheremetyevo firefighters reached a blazing Aeroflot Sukhoi Superjet 100 within the required response time, and extinguished the fire in about 16min, according to the airport operator.
The operating company says fire-rescue vehicles arrived at the scene on 5 May about 1min ahead of the regulatory standard.
Russian regulations dictate that firefighters must be able to reach the ends of each runway within 3min.
Sheremetyevo’s operator has based its assessment on evidence including radio communications.
It says the aircraft’s captain informed air traffic control that the flight was returning to the airport 10min after it departed for Murmansk.
The captain told controllers that there had been a loss of radio communication as well as a loss of automatic aircraft control.
After the aircraft landed heavily on runway 24L at 18:30, says the airport operator, an air traffic controller sounded an alarm, and two firefighting vehicles arrived at the scene within 2min of the touchdown.
Four more rescue vehicles subsequently arrived about a minute later.
Firefighters entered the burning aircraft about 5min after it landed and the fire was “completely extinguished” at 18:48, says the airport operator.
Twenty-six rescuers had been on board the six airport fire vehicles, and four ambulances attended. The operator adds that the emergency response involved 73t of extinguishing agent including 6.5t of foam.
All but one of the 41 victims of the accident has been identified, says the federal Investigative Committee.