German investigators are preparing a response to extraordinary criticism from Air Berlin following an incident involving a Boeing 737-800's diversion to Chania in Crete.
The aircraft, operating flight AB2242, had been bound for Heraklion from Munich on 21 September 2012. It executed a go-around at Heraklion and diverted to Chania.
German air accident investigation authority BFU, in a September bulletin, says that - following a hold and then the go-around - crew declared an emergency but states that the aircraft's fuel reserves fell below the "minimum allowable".
It has not clarified whether this refers to final reserve fuel level, the minimum quantity which must legally remain in the fuel tank upon landing.
Air Berlin says that, "contrary" to the BFU bulletin, the fuel level on the 737 was "always over the legally-required limit".
"Even after the safe landing in Chania, fuel levels were still sufficient, meaning more than the legally-specified fuel reserves were present," it says.
Air Berlin says the crew declared an emergency en route to Chania as "purely a matter of precaution" to avoid delays at the diversion airport.
The airline insists that internal analysis of the incident shows the fuel uplift for the aircraft was "in accordance" with European legal requirements and that the carrier acted in accordance with regulations.
"In many areas the depiction in the BFU bulletin...does not correspond with the facts," it adds.
BFU says its investigators are aware of the airline's claims and that the authority is to discuss the incident during its regular conference today.