The Italian ANSV released their final report of their investigation into the August 2005 ditching of a Tuninter ATR-72 due fuel exhaustion.
The cause of the accident was, in the first place, thw wrong procedure used for the replacement of the Fuel Quantity Indicator, FQI by the maintenance staff of the airline, who installed the FQI of an ATR-42 on an ATR-72.
The amount of fuel indicated by an FQI for ATR-42 installed on ATR-72 aircraft is higher than that actually present in the tanks. In particular, on ATR-72, compared with an amount of fuel equal to zero, the FQI of an ATR-42 indicates a total amount of fuel equal to or greater than 1800 kg, which corresponds to the amount communicated by the crew of TS-LBB to the air traffic controller. The incorrect procedure represents the triggering factor, which led to the ditching of the aircraft due to lack of fuel. (ANSV)