Divers Recover Recorders from Laos ATR Wreckage

 - December 1, 2013, 1:40 AM

After an exhaustive two-week search, local salvage divers recovered the flight-data and cockpit voice recorders from the Lao Airlines ATR 72-600 that crashed into the Mekong River in Laos on October 16. Divers initially lost the signal of the recorders on October 27 after the sonar and acoustical locating equipment provided by France’s Bureau d’Enquêtes et d’Analyses (BEA) ceased working due to excess usage in the turbid waters of the Mekong. Two members from the Air Accident Investigation Bureau of Singapore (AAIB) replaced the equipment the following day.

On October 29 divers salvaged a fractured section of the starboard wing. The following day they located the empennage, despite concerns that the tail section and the recorders were becoming increasingly buried in the Mekong River bed. The 30-foot section broke apart from the aircraft and had become weighed down by rocks and sand.

Crews made several attempts to raise the empennage over the course of two days. However, the tail section repeatedly slipped from its tether. After BEA officials showed divers how to locate the position of the flight-data recorder, they managed to retrieve the device by hand on October 31.

A day later the divers and salvage crew raised the empennage and extracted the cockpit voice recorder from the wreckage. They also recovered the airplane’s horizontal stabilizer. Government officials took possession of the recorders and planned to send them to one of four countries for analysis. As of November 10 divers continued to salvage other parts of the aircraft from the Mekong.

The regional turboprop, en route from the Laotian capital Vientiane to the southern city of Pakse, crashed in rainy weather while on approach to Pakse International Airport, killing all 44 passengers and five crewmembers. Lao Airlines manager of flight standards and safety Phonesuthat Thammachalurne and Laotian director of civil aviation Yakua Lopangkoa confirmed that air traffic controllers were monitoring the ATR’s approach when they observed that the aircraft’s altitude had dropped too low as it approached the airport. The crew also failed to activate the pilot-controlled airport lighting to high intensity. Reports indicated broken clouds prevailed at 1,000 feet agl. ATC instructed the pilot to perform a go-around. Seconds later, controllers lost communications with the aircraft.

The turboprop crashed less than 2,000 feet from the riverbank of the island Don Phaling. Several government officials suggested that the aircraft’s landing gear touched down on the edge of Don Phaling before it crashed into the Mekong. Investigators found three shallow indentations in a naturally cleared area on the bank, some 25 feet above the river. Debris from the aircraft, including small pieces of the airframe, was scattered throughout the area.

The pilot, a 58-year-old Cambodian national with 30 years of flight experience, had flown for the carrier for four years.

The October 16 crash marked the third fatal accident for Lao Airlines since it started operations in 1976 under the name Lao Aviation. In 1993, all 18 occupants died when a Harbin Yunshuji Y-12-11 struck trees in heavy fog, crashed and immediately caught fire. In 2000 a second Harbin Yunshuji Y-12-11 crashed in the mountains while on approach, killing eight passengers.

Among five other reported incidents, a Cessna Grand Caravan made a successful emergency landing in a rice field following engine failure in 2009, said Lopangkoa. He also reported that in April of this year a de Havilland Canada Twin Otter 300 took off with a known landing-gear problem and crashed 650 feet from the end of the runway.

Lao Airlines has operated a fleet of ATR 72s for the last 10 years. The carrier also operates Airbus A320s and Chinese-made MA-60s for regularly scheduled short-haul domestic flights and routes to China, Thailand, Cambodia, Korea and Vietnam. o