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 747-400 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 four crew members on board and 35 residents on the ground – were killed. It was Kyrgyzstan's deadliest plane crash since the crash of Iran Aseman Airlines Flight 6895 in 2008.
The subsequent investigation found that the aircraft failed to acquire the correct instrument landing system's signal. Due to a series of errors by the pilots, the aircraft flew significantly higher than the proper altitude for approach. The autopilot then picked up a false glide slope signal. Believing that they had captured the correct glide slope, the pilots let the autopilot put the aircraft into a descent. It then crashed into a residential area past the runway, mere seconds after a go-around was initiated.
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 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 10,808 hours of flying time, including 820 hours on the Boeing 747. His co-pilot was Kazım Öndül, also aged 59, who had logged 5,894 hours of flying time, 1,758 of which were logged on the Boeing 747. Loadmaster Ihsan Koca and cargo handler Melih Aslan were also on board the aircraft.
Accident
Flight 6491 was an international freight flight from Hong Kong's Chek Lap Kok Airport to Istanbul's Atatürk Airport with a transit at Bishkek's Manas International Airport. Two airports, Astana and Karaganda, were listed as alternate destinations in case the weather in Bishkek was not suitable for landing. The flight would be flown by ACT Airlines on behalf of Turkish Airlines. After a two-hour delay, the aircraft took off from Hong Kong at 03:12 local time and would be expected to arrive in Bishkek approximately 6 hours later.
Approach
In order to land in Manas, the crew of Flight 6491 would have needed to fly towards several sets of waypoints beforehand. The first one would be RAXAT, in which the crew would be obliged to fly at a minimum altitude of 17,000 ft due to the high terrain in the area. After passing RAXAT, the crew would then proceed to TOKPA and would be cleared to descend further until the aircraft's instruments managed to capture the ILS signal, which was necessary for a progressive descent to Manas, allowing the crew to safely land despite the mountainous terrain.
As the aircraft got closer to Manas, the pilots started their briefing for the approach. Weather reports indicated that Manas was covered in fog and that visibility had deteriorated. In response to the inclement condition, Captain Dirancı laid out the steps that the crew would take during the approach. Dirancı stated that a landing would only be commenced if they had managed to see the runway lights. If during the approach they had intercepted the ILS signal at an altitude lower than 1,000 ft, then a go-around would be called instead. The rest of the crew followed his instructions and didn't voice any objections.
Having finished with the approach briefing, the crew requested descent clearance to the ATC. The controller approved their request and ordered the crew to descend to 22,000 ft, which pleased Captain Dirancı as he had been aiming to land in Manas as soon as possible. Around eight minutes later, Captain Dirancı asked First Officer Öndül to request another descent clearance. The controller, however, denied clearance and asked the crew to stay on 22,000 ft as they were still flying above the Tian Shan mountains. Captain Dirancı thought that they would be allowed to descend sooner and was surprised to hear this, causing him to curse at the ATC.
Getting anxious with the aircraft's altitude, Captain Dirancı ordered First Officer Öndül to request another clearance. This time, their request was approved, and the crew was cleared to descend to flight level 180 and was not allowed to fly lower due to the mountains. Flight 6491 was eventually handed over to the approach controller. Still not satisfied with their altitude, Captain Dirancı ordered his first officer to ask for another descent clearance, even though they had not reached waypoint RAXAT, the first waypoint for the approach. While contacting the approach controller, the crew immediately asked for permission to descend. The controller did instruct the crew to descend to 6,000 ft to proceed to waypoint TOKPA. Since this procedure required a steep descent, Captain Dirancı responded with dismay.
After passing waypoint RAXAT, the crew initiated their descent from 18,000 ft to 6,000 ft. The autopilot was set with the targeted airspeed of 260 knots, and the engines were set to near idle. The anti-icing was turned off. Due to the high rate of descent, the airspeed soared. In response to this, Captain Dirancı stated that he would maintain such speed and would only correct it later on. Despite the airspeed, the descent was not as quick as Captain Dirancı had hoped, and thus he deployed the airbrakes when the aircraft was at 12,200 ft.
The aircraft eventually reached waypoint TOKPA at 9,200 ft, approximately 3,000 ft higher than the altitude that had been instructed earlier. The crew, however, decided to continue with the approach. ATC eventually cleared them for further descent and to head towards another waypoint to intercept the ILS glideslope signal. Both pilots then tried to find the airport's glideslope signal, but to no avail. Struggling to find the signal, Captain Dirancı ordered First Officer Öndül to look for the runway. They eventually passed the airport's final approach point, but no signal was received from the ILS. Angered by this, Captain Dirancı vented his anger by cursing the ATC again, to the surprise of First Officer Öndül, who tried to calm down Dirancı. Despite not acquiring the ILS signal, the crew still continued their approach to Manas.
While nearing Manas, the ATC worker cleared Flight 6491 to land. On board the aircraft, the crew were still searching for the signal. Suddenly, the aircraft's flight system detected the signal from the ILS. At an altitude of 3,400 ft, the autopilot captured it and finally initiated the descent to Manas.
Descent and accident
Captain Dirancı immediately engaged the aircraft's autoland system, and the aircraft began its descent with a nose-down attitude of 3 degrees. With their imminent landing, the crew tried to search the runway lights once more. The weather in the surrounding area was still filled with thick fog, hampering their attempts. As the aircraft was descending, its Ground Proximity Warning System (GPWS) suddenly blared, "Glide slope! Glide slope!" which was met with no response from the crew. The alarm eventually ceased when the aircraft reached an altitude of 200 ft.
Getting nearer to the ground, First Officer Öndül stated that the aircraft was approaching the airport's minimum decision altitude, the height at which the pilots needed to decide whether to land or go around unless they had acquired visuals with the runway. Trying to see the runway once more, the crew attempted to locate the runway again. The aircraft reached the minimum decision altitude, but the pilots still weren't able to locate the runway. As such, Captain Dirancı immediately called for a go-around.
But as the aircraft was starting to climb, rows of trees suddenly came into view. The right wingtip clipped the treetops while the landing gear and engines ploughed through the airport's perimeter fence. The aircraft came back down, touched down, and bounced back into the air before it crashed into another fence. Its right wing then slammed onto houses, causing the wing to disintegrate. The aircraft then turned to the right before flipping over completely, bursting into massive flames and engulfing dozens of houses in the area.
Response
Search and rescue operation
At 07:17 local time (01:17 UTC) on 16 January 2017, the aircraft crashed nearly 1 km (3,300 ft) beyond the end of runway 26 at Manas International Airport, at a residential area known as Dacha-SU (Kyrgyz: Дача-СУ). Minutes after the accident, at 07:23 local time, Manas Airport issued an alert to all rescue personnel. The first airport fire brigade arrived at the accident site on 07:30 local time. Reinforcements from Kyrgyzstan Emergency Control Ministry arrived around 10 minutes later. The accident site was then cordoned off. Residents who were trapped inside their homes were immediately evacuated. About 20 local residents also volunteered in the search and rescue operations. In total, there were 1,308 personnel who took action in the accident removal actions.
Authorities reported that at least 38 structures were destroyed, including 19 homes and 12 outbuildings. A total of 7 houses were partially destroyed by the accident. Some of the outbuildings housed livestock, which were killed by the accident and fire.
A total of 39 people were killed in the accident: all four crew members and 35 residents of Dacha-SU. One of the local volunteers also died of "natural causes" during the search and rescue operation. Among the dead were 17 children. Since the accident happened in the morning, most of the residents at the time were either asleep or preparing for their daily activities. There were reports that entire families had been wiped out by the accident. Autopsies report revealed that some of the victims had died from being trapped inside their homes due to the intense post-impact fire, which spread throughout the neighborhood. Others were killed by collapsing rubble. One of the victims succumbed to their injuries while being treated at a hospital.
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, including 17 children, were injured with varying degree of injuries. Manas International Airport was closed, with all flights cancelled, following the accident.
Two days after the accident, the search and rescue operation was ended, after authorities believed that they had recovered all victims from the accident site.
Government response
The Ministry of Emergency deployed more than 1,000 personnel to secure the accident site and safely remove the wreckage. The debris was scattered over 1 hectare. High-ranking officials eventually visited the accident site to observe the search and rescue operation, including then-Prime Minister Sooronbay Jeenbekov, Deputy Prime Minister Mukhammedkalyi Abylgaziev, Minister of Emergency Situations Kubatbek Boronov and Minister of Transportation and Roads Zhamshitbek Kalilov. 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.
The following day was declared a day of national mourning in Kyrgyzstan. The flag of Kyrgyzstan would be flown at half-mast in every public institution and diplomatic building. Accordingly, numerous entertainment programs were cancelled by radio and television stations. Several cultural programs were also cancelled. 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.
In response to the accident, there have been concerns regarding the presence of houses near the airport, prompting calls for resettlement from multiple government officials. MPs of the Jogorku Kenesh asked the government to demolish the dachas and relocate the residents to a safer place. Concerns began to grow as an impromptu inspection revealed that the houses had been built illegally, as the dachas were only meant for seasonal dwellings during the summer and spring, but the residents opted to stay permanently. Many residents were unwilling to move due to financial reasons and instead asked the settlement to be given an official status. As issues regarding the dachas remained unresolved, the residents held a rally in front of the Bishkek White House to ensure their safety and the status of their homes.