On 6 August 2005, the Tuninter ATR 72 ditched into the Mediterranean Sea about 18 miles (29 km) from the city of Palermo.

The aircraft, an ATR 72–202, had its fuel quantity indicator (FQI) replaced the night before the flight, but technicians inadvertently installed an FQI designed for the ATR 42, a similar but smaller airplane with smaller fuel tanks.

First, the investigation examined how the incorrect fuel quantity indicator (FQI) came to be installed on the plane.

[4] The investigation also found that when departing from Tunis on the Tunis-Bari route taken before Flight 1153, the captain noticed by reading his cockpit displays that the aircraft's fuel level seemed to have increased overnight, but did not find a corresponding refueling slip.

The correct indicator would have shown that there were just 540 kilograms in the tanks when departing for the Bari-Djerba route, insufficient to reach the destination.

During an engine flameout, crews must feather the propellers to reduce the drag on the blades so the plane can glide a farther distance.

Simulation results suggested that, handled optimally, the ATR could have reached Palermo with the tailwind of that day.

In contrast, the captain of the Tuninter ATR – whose FQI showed sufficient fuel remained – focused initially on trying to restart the engines in the hope they would respond.

The final investigative report suggested that airlines train their pilots to deal with unusual situations.

[citation needed] In March 2009, an Italian court sentenced the pilot, Chafik al-Gharbi, to 10 years in prison for manslaughter.

"[9] The criminal investigation and subsequent sentencing caused considerable controversy in Tunisia and, to a lesser extent, in the civil aviation world.

Unedited cockpit recordings leaked to the public demonstrated the Palermo air traffic controller as having a poor grasp of English, failing to assign the distressed flight its own radio frequency on which to communicate, and giving the pilots incomplete and/or useless information about their position.

[10] In April 2012, the court of Palermo, Italy reduced the sentences of seven of the Tunisian airline personnel charged.

[11] The crash was featured in the 2009 episode "Falling Fast", of the Canadian-made, internationally distributed documentary series Mayday.