Accident ATR 72 near Palermo

ATR 72-202 (registration number TS-LBB, serial 258) was released in 1992 (the first flight took place on March 12 under test b / n F-WWLE). March 27 of the same year was purchased by the Tunisian airline Tuninter . Equipped with two Pratt & Whitney PW124B turboprop engines . The last scheduled repair took place on May 25, 2005, no problems were found. One of the oldest aircraft of the airline. On the day of the disaster, he made 35,259 take-off and landing cycles and flew 29,893 hours ^{[1] [2]} .

The crew of the TUI 1153 flight was as follows:

• The aircraft commander (FAC) is the 45-year-old Chafik Al Gharbi ( Arabic: afيق الغربي ). A very experienced pilot, flew a Boeing 737-200 . 7182 hours flew, 5582 of them on ATR 42/72.
• The co - pilot is 28-year-old Ali Kibaer Al-Aswad ( Arabic: Ali Kebaier Al-Aswad , Arabic. علي كبيّر الأسود ). 2431 hours flew, 2130 of them on ATR 42/72.

Two cabin crew worked in the cabin .

Maintenance engineer Chokri Harbaoui ( Arabic: ouري الحرباوي ) was not a member of the flight crew and was in the passenger cabin. His tasks included control of aircraft refueling at airports and, if necessary, ground maintenance ^{[* 2]} . After an emergency, the PIC through the flight attendant asked the engineer to go into the cockpit, where he remained until the aircraft landed on the water.

TUI 1153 flight departed from Bari International Airport (Italy) at 14:32 local time and headed for Djerba (Tunisia).

At 15:24 at an altitude of 7000 meters, engine No. 2 (right) suddenly stopped at the plane, and the crew requested a reduction from the dispatcher, citing technical problems that arose. After 1 minute 40 seconds, engine No. 1 (left) also stopped. The crew requested a landing at the nearest airport to Palermo (Italy) and transmitted a distress signal. The aircraft began to plan from a height of 5180 meters. Pilots were sure that there was still jet fuel, since the fuel gauge showed the presence of 1800 kilograms of jet fuel. But attempts to restart the engines failed.

The stop of electric generators that rotated from the engines led to a de-energization of the navigation equipment, which allowed the crew to determine the remaining distance to the rangefinder of the Palermo airport. During the descent, the crew several times asked the dispatcher Palermo at what distance from the airport the plane is. The dispatcher’s responses indicated that there wasn’t enough headroom for planning such a distance, and the PIC decided to make an emergency landing on water.

At approximately 3:40 p.m. (1:40 p.m. UTC), after 16 minutes of planning, a TUI 1153 flight at a speed of 230 km / h splashed onto the Mediterranean Sea 26 kilometers from Palermo and collapsed into three parts. The nasal and tail parts sank for 20-30 minutes, and the middle part, including wings and engines, remained afloat. 16 people died - 1 crew member (senior flight attendant) and 15 passengers, including an airline engineer flying as an official passenger. 23 people survived - 3 crew members (FAC, co-pilot and second flight attendant) and 20 passengers; 11 of them were injured. They were able to get out of the plane and get to the wings, which remained afloat.

After the disaster, the search for flight recorders began. Initially, investigators suggested that the ATR 72 ran out of jet fuel. They began to study the fuel system for defects, as well as jet fuel for pollution, but everything was in order.

Tuninter Airlines provided a magazine with technical data about the aircraft, in which the crew wrote a record about the malfunction of the remaining fuel indicator - several segments did not work on the seven-segment digital indicator . That same evening, the technician fixed the malfunction, noting in the journal that he had replaced the faulty type 748-681-2 device with a type 749-158 device. The type of newly installed fuel remaining indicator is intended for use on ATR 42 aircraft, which were also operated by Tuninter. But, despite the identical appearance and identical replacement procedure, these devices are not interchangeable. Both of them convert the analogue electrical signal of a capacitive fuel level sensor in the tank to the amount of fuel, but they are calibrated differently, respectively, according to different geometry of the fuel tanks and different number of sensors. The aircraft manufacturer's instructions, which were in effect at that time, did not require the technician to verify the readings of the replaced device by determining the fuel level with a manual measuring tube.

Thus, instead of the remaining jet fuel of 790 kg recorded in the journal at the end of the flight, after which the crew made a record of the malfunction, the fuel gauge began to show the remaining 3,100 kg .

Later, the investigation established that the use of a different model of the remaining fuel indicator was due to the fact that the indicator database 748-681-2 was not found in the airline’s database, which contained information about the availability of spare parts, and it was incorrectly indicated about 749-158 that it could used on ATR 72. There is no such error in the catalog of the aircraft manufacturer.

In preparation for the Tunisia – Bari flight (the flight preceding the crash), the PIC calculated the required amount of jet fuel: 3800 kg . The refueling process continued until the amount of fuel on board, according to the readings of the fuel gauge, reached the desired value. From the receipt signed by the tanker operator and engineer, it follows that 465 kg of fuel was poured, which is very different from the expected 700 kg (difference of 3800 and 3100 ), which would be poured if the fuel gauge worked correctly. This did not attract the attention of the crew.

Checking the documents for refueling, FAC found that there was no receipt for refueling the aircraft from 790 to 3100 kg . At the request of the FAC, the dispatcher replied that it was likely that this receipt was mistakenly left by one of the crews, who were supposed to carry out other flights on this aircraft according to the plan, but refused to fulfill them. The dispatcher also promised to ensure that the receipt was found and handed on board upon the return of the aircraft to Djerba. Such a promise satisfied the FAC, and he decided to fly.

Upon arrival in Bari, the displayed fuel balance was 2300 kg . The fuel required for the next flight, taking into account the actual load, was 2700 kg . During the refueling process, carried out according to the same scheme as in Tunisia, 265 kg of fuel was loaded into the plane. The crew again did not pay attention to the difference between the actually filled amount and the expected 400 kg .

On the flight simulator, investigators proved that the plane could fly to Palermo in glider mode, in which the engine screws must be feathered, but the screws are not feathered to restart. Pilots, believing that there was a supply of fuel on board, instead of planning, made attempts to restart the engines. If the PIC knew that he had run out of jet fuel, then perhaps he would have done everything to plan as long as possible. Nevertheless, one action of the commander saved more lives: just before the plane hit the water, he raised his nose. Thus, the aircraft lost its tail upon impact, and a larger number of survivors could get out through the hole that formed.

Compensation

Tuninter Airlines reimbursed families of passengers for € 20,000 . On September 7, 2005, the Italian government banned flights for Tuninter aircraft in Italian airspace.

Court

In March 2009, an Italian court sentenced flight commander 1153 to 10 years in prison for manslaughter. According to prosecutors, after the failure of the aircraft engines, the FAC did not do everything possible to reach runway No. 25 in Palermo. Witnesses say he panicked and began to pray out loud, rather than trying to fly to the nearest airport. Over the past 5 minutes, a voice recorder in the booth recorded several seconds of scattered, religiously oriented interjections such as God, save us! .

Another 6 people, including the co-pilot of flight 1153, as well as the director of Tuninter airline were sentenced to 8 to 10 years. They will not serve time until the appeal process is completed.

• The crash of Tuner Flight 1153 is featured in season 7 of the Canadian documentary television series Crash Investigation in the Emergency Splash series.
• It is also mentioned in the MSNBC American documentary television series Why Planes Crash in the Prepare for Impact series ( Brace For Impact ).

Comments

Sources

• Description of the disaster on the Aviation Safety network
• Air Crash Investigation - Emergency Water Splash
• Agenzia nazionale per la sicurezza del volo
  • Final Accident Report ( Archive )
  • Final Accident Report (Italian) ( Archive )
  • Tuninter ATR 72 accident: the safety Recommendations addressed to European Aviation Safety Agency - EASA
  • Ref. 2818 / INV / 433/5/05 Safety Recommendation
  • “ Incidente ATR 72 Tuninter: nuova raccomandazione di sicurezza inviata all'EASA .” ( Archive , PDF , Archive ) (Italian)
• Photographs of the incident
• “ Atr 72, dopo la sentenza i parenti indossano magliette con i volti delle vittime del disastro aereo .” La Repubblica (Palermo). March 23, 2009. - Photographs of the victims