Turkish Airlines Flight 6491

Turkish Airlines Flight 6491

The crash site and the wreckage of Flight 6491
Accident
Date	16 January 2017 (2017-01-16)
Summary	Controlled flight into terrain during go-around
Site	Manas International Airport, Bishkek, Kyrgyzstan 43°03′26″N 74°26′14″E
Total fatalities	39
Total injuries	36
Aircraft
Aircraft type	Boeing 747-412F/SCD
Operator	ACT Airlines on behalf Turkish Cargo
IATA flight No.	TK6491
ICAO flight No.	THY6491
Call sign	TURKISH 6491
Registration	TC-MCL
Flight origin	Hong Kong International Airport, Hong Kong, China
Stopover	Manas International Airport, Bishkek, Kyrgyzstan
Destination	Istanbul Atatürk Airport, Istanbul, Turkey
Occupants	4
Passengers	0
Crew	4
Fatalities	4
Survivors	0
Ground casualties
Ground fatalities	35
Ground injuries	36

Turkish Airlines Flight 6491 was a scheduled international cargo flight operated by ACT Airlines on behalf of Turkish Cargo, from Hong Kong to Istanbul via Bishkek, Kyrgyzstan. On 16 January 2017, the Boeing 747-400F flying the route crashed in a residential area while attempting to land in thick fog at Manas International Airport, Bishkek. A total of 39 people – all 4 crew members on board and 35 residents on the ground – were killed.

The subsequent investigation found that the aircraft failed to properly acquire the instrument landing system's signal, remaining significantly higher than the correct approach path while overflying the entire length of the runway; it then collided with houses seconds after initiating a go-around.

Accident

The aircraft involved, seen at Maastricht Aachen Airport, 5 days before the accident

At 07:19 local time (01:19 UTC) on 16 January 2017, the aircraft crashed nearly 1 km (3,300 ft) beyond the end of runway 26 at Manas International Airport, in thick fog. According to initial reports, the aircraft failed to gain enough altitude while attempting a go-around. It crashed into terrain and destroyed 38 houses. Kyrgyz authorities later stated that the crew were making a determined attempt to land the aircraft instead of aborting the landing.

A total of 39 people were killed in the crash: all four crew members and 35 residents of Dacha-SU (Kyrgyz: Дача-СУ), a residential area located approximately 2 kilometres (1.2 mi; 1.1 nmi) to the west of the airport. Among the dead were 17 children.

Witnesses and rescuers reported that they found the pilot still conscious strapped into his seat, from which he had to be cut free. He later died while en route to a hospital.

Thirty-six people on the ground were injured, including 17 children. Thirty-eight houses were destroyed at the crash site, and a further seven were damaged. Manas International Airport was closed, with all flights cancelled, following the accident.

Background

Aircraft

The aircraft involved, manufactured in February 2003, was a Boeing 747-412F, registered as TC-MCL with serial number 32897. The aircraft, originally registered as 9V-SFL, was first delivered to Singapore Airlines Cargo. After multiple periods of storage, the aircraft was acquired by LCI Aviation in 2015. It was leased it to Istanbul-based cargo company ACT Airlines, which then began operating it on behalf Turkish Airlines Cargo from 2017. The aircraft had logged 46820 airframe hours in 8308 takeoff and landing cycles and its last C-check maintenance check had been completed on 6 November 2015. It was also equipped with four Pratt & Whitney PW4056-3 engines.

Crew

In command was Captain İbrahim Dirancı, aged 59, who had logged 10808 hours of flying time, including 820 hours on the Boeing 747. His co-pilot was Kazım Öndül, also aged 59, who had logged 5894 hours of flying time, 1758 of which were logged on the Boeing 747. Loadmaster Ihsan Koca and cargo handler Melih Aslan were also onboard the aircraft.

Immediate response

Deputy Prime Minister Mukhammedkalyi Abulgaziyev reported that, by late morning, more than 1,000 rescue workers were at the scene. Minister of Health Talantbek Batyraliyev reported that by 11:46 a.m. local time, around 56 doctors and psychologists and 14 ambulance crews had been dispatched to the scene.

A number of heads of state expressed condolences, including the presidents of the other members of the Commonwealth of Independent States and the Prime Minister of Turkey.

The following day was declared a day of national mourning in Kyrgyzstan.

Investigation

The location of the crash (red square) past the end of runway 26 at Manas Airport

The cause of the crash was not immediately clear. Kyrgyzstan's Emergency Situations Minister, Kubatbek Boronov, stated that it was foggy at Manas at the time of the crash, but that weather conditions were not critical. By the afternoon of 16 January, one of the two flight recorders had been found, and the other was located later in the recovery process. Both the flight data recorder (FDR) and cockpit voice recorder (CVR) were damaged in the crash, but investigators were still able to retrieve data from both recorders.

Deputy Prime Minister Abulgaziyev suggested that the cause may have been pilot error, noting that eleven aircraft had landed safely, despite the same weather conditions, on the previous day. He added that the aircraft had attempted to land twice and had damaged the runway lights at one stage. This statement was at odds with another official statement that the aircraft crashed during its first landing attempt.

The Interstate Aviation Committee (IAC or MAK) of the Commonwealth of Independent States opened a technical investigation.

The Turkish Transportation Ministry said it had sent two experts from its accident investigation board to Bishkek to assist Kyrgyz authorities. A technical team from Boeing visited the site to offer help and advice, under the auspices of the American accident investigation body, the National Transportation Safety Board.

Many initial press responses stated that a Turkish Airlines aircraft was involved in the accident. In response, Turkish Airlines released a statement saying that neither the aircraft nor the crew were part of the airline, calling it an "ACT Airlines accident". Journalists were threatened by Turkish lawyers claiming reputational damage. Nevertheless, the flight was operated under a Turkish Airlines flight number.

Aerial view of the crash site

The preliminary investigation report found that the aircraft descended late and captured a false glideslope. On capturing the false glideslope, the three autopilots then initiated the descent of the plane in low visibility conditions. Initially all three autopilots were engaged (LAND 3). The false glideslope was lost 15 seconds after it was acquired and AP CAUTION and FMA FAULT 2 events were recorded, meaning that the autopilots would continue to descend the aircraft on a 3-degree slope using inertial guidance. One autopilot disengaged (LAND 2) and the remaining autopilots flew down to the decision height. The crew did not acquire the required visual reference at the decision height (99 ft (30 m)), and initiated a go-around 0.5 seconds later at 58 ft (18 m) radar altitude by pressing the TOGA switches. Given the slightly up-sloping terrain after the end of the runway, the aircraft did not have sufficient height at that point to climb out safely.

Final report

On March 3, 2020, the Interstate Aviation Committee (MAK) released is final report into the crash stated that probable cause was the loss of control of the pilots over the aircraft position in relation of the glideslope during the instrumental approach, carried out at night in weather conditions suitable for ICAO CAT II landing. The report also listed numerous contributing factors.

On 17 January 2017, the Kyrgyz press reported that ACT Airlines had declared the intent to pay the victims compensation for all material and immaterial losses, citing a press release on the ACT Airlines web site. The press release itself, however, stated only that losses were covered by insurance.

External links

• "Boeing 747-412F TC-MCL 16.01.2017." Interstate Aviation Committee. Content in Russian: "Боинг 747-412F TC-MCL 16.01.2017."
• Drone footage of TK6491 crash site on YouTube