Sicily begins investigation, but flight data recorder may be too deep to recover
The public prosecutor in Palermo, Sicily says he hopes to complete initial inquiries quickly into the 6 August ditching of a Tuninter ATR 72, but admits that recovering the flight data recorder (FDR) may be “too expensive” because it is at a depth of 1,200m (3,930ft) in the Mediterranean Sea.
The captain, who survived despite injury, has told the authorities that while trying to divert to Palermo after the failure of one of the Pratt & Whitney Canada PW124B engines, the crew was forced to ditch about 25km (14nm) to the north of the island when the second engine stopped.
In Italian territories like Sicily the judiciary is in charge of the inquiry, and technicians from the accident investigation authority ANSV work with them.
ATR says the 13-year-old ATR 72-200 (TS-LBB) was carrying 35 passengers and four crew and had logged 29,710h and 34,790 cycles by the end of May. Operated by Tunisair’s regional arm Tuninter, the aircraft was carrying Italian holidaymakers on a charter from Bari in south-eastern Italy to the Tunisian island of Djerba.
Most of the statements on the accident have been issued by the Palermo public prosecutor’s office, which confirms that among the 39 people aboard the aircraft, 13 are known to have died, three are listed as missing, and 23 were rescued and taken to Palermo by boat. It adds that post-mortems have established that at least four passengers drowned, although they showed signs of injuries from the impact.
Chief prosecutor Pietro Grasso lists a number of potential causes being investigated, admitting that unless the Italian navy can recover the FDR and cockpit voice recorders the inquiry may have to work with evidence from air traffic control tapes and the recovered floating wreckage. The fuel tanker at Bari from which the aircraft uplifted 340 litres (90USgal) has been found not to be contaminated. This was a small upload as the aircraft’s fuel capacity is around 6,000 litres.
Time for lifejackets
The captain has stated that the ATR 72’s right engine failed a little less than an hour into the flight when the aircraft was in the cruise. The crew made an emergency call at about 15:20 local time, advising air traffic control they were diverting to Palermo, but a few minutes later the left engine also stopped. With both propellers believed to have auto-feathered, the aircraft ditched into the sea 20min later. Some survivors report they had time to don lifejackets before the ditching.
Based on the weather report for Palermo, the ditching was made in good visibility with a light wind. There was no heavy swell, but survivors say the sea was choppy. On contact with the water, the aircraft broke into three sections; the cockpit and the fuselage forward of the wing, and the fuselage aft of the wing both separated and sank quickly; the wing, with engines attached, floated and has been recovered.
Source: Flight International