Baikal Airlines Flight 130 was a scheduled domestic passenger flight from Irkutsk to Moscow operated by a Baikal Airlines Tupolev Tu-154 that crashed onto a dairy farm on 3 January 1994 in Mamony whilst the pilots were trying to return to the airport following a mid-air emergency. All 124 people on board were killed. Another person was killed on the ground.
With 125 deaths, it remains as the deadliest crash in Russia during the 1990s.
The investigation conducted by Russian MAK concluded that the crash was caused by loss of control due to an in-flight fire. One of the Tupolev Tu-154's engine starters failed in mid-flight and broke apart. The failure inflicted damages on the oil lines and hydraulic lines around the engine, igniting uncontrollable flames. The flight crew attempted to return to the airport, but due to the damaged hydraulic lines they could not control the aircraft and it crashed onto the farm.
Aircraft
The aircraft was a Tupolev Tu-154M with a manufacturer serial number of 89A801, equipped with three D-30KU-154 turbofan engines. It was built in May 1989 and had its first flight with Aeroflot. Prior from being transferred to Baikal Airlines, the aircraft was registered as CCCP-85656. It was purchased by Baikal Airlines in 1992 and re-registered to RA-85656 in 1993.
Passengers and crew
Flight 130 was carrying 115 passengers and 9 crew members. Then-Minister of Transport Vitaly Efimov stated that the aircraft was carrying 4 extra passengers who were not listed on the official manifest.
Majority of those on board were Russians, but Baikal Airlines confirmed that there were at least 17 foreigners on board. The manifest released by the airline showed that there were 10 Germans, 4 Chinese, one Austrian, one Indian and one Japanese. The rest were Russians. There were 5 children and one infant on board the aircraft. Most of the passengers were tourists who had just finished their vacation in Lake Baikal.
The flight crew were consisted of the following:
- Captain Gennady Stepanovich Padukov, who had a flying experience of more than 16,000 hours
- First Officer A. G. Zhavoronkov
- Navigator V. I. Molnar
- Flight Engineer Ilya Petrovich Karpov, with a total flying experience of around 14,000 hours
- Inspector O. V. Likhodievsky
Accident
Before take-off
Flight 130 was scheduled to take off at around 12:00 p.m., heading to Moscow with 115 passengers and 9 crew members. Most of the passengers were tourists who were heading home from holidaying at Lake Baikal. The flight was commanded by Captain Gennady Padukov, and his co-pilot was First Officer A. Zhavoronkov. The flight would normally take around five hours.
Following the aircraft's fuelling, the flight crew requested clearance and started the engines. Engines one and three started normally, but engine two failed to start and did not respond to a restart attempt. Nearly 17 minutes later, they finally managed to light the final engine. Frustrated, Captain Gennady could be heard telling his co-workers "to tell the engineers that had prepared the engines prior to the flight that they had done their job poorly.".
A red light warning suddenly turned on. The light warned the crew about the dangerous speed of the air start unit on engine two. Flight engineer Karpov, who was initially perplexed, tried to turn off the light, but failed. He informed the issue to the pilots, who discussed the problem.
After some deliberations, they decided to ignore it altogether. Knowing that they had faced the same problem before, they paid it little attention and continued with the flight. The crew then began taxiing to the runway, but Karpov remained pre-occupied with the alarm, as the light remained illuminated in front of his seat.
The problematic engine was not turned off and the crew continued preparing for takeoff. After finishing the takeoff checklist and configuring the aircraft, the engine thrust was set to takeoff power, and Flight 130 took off at 11:59 local time.
Start of failure
Barely 4 minutes after takeoff, just when the aircraft was about to reach an altitude of 6,000 meters, the fire alarm suddenly blared. Flight engineer Karpov announced that a fire had broken out on the defective engine two. It was turned off and the crew immediately followed the established procedure for in-flight fire, but the alarm continued.
The flight crew then tried to douse the flames by turning on the fire extinguishing system, which operated until exhausting its mixture. However, flight engineer Karpov later reported that fires were still present on engine two, and now had spread to the APU compartment. Due to the quick spread, Captain Gennady decided to return to Irkutsk for an emergency landing. The navigator immediately charted their course. Meanwhile, the siren continued to sound.
The ATC quickly approved Flight 130 for an emergency landing and ordered them to descend to 900 ft for an approach from the south of the airport.
After radioing the ATC for an emergency landing, Karpov realized that the hydraulic pressures had dropped. First Officer Zhavoronkov then announced that the landing gear would be extended, but the landing gear remained stuck inside the wheel well. Captain Gennady noted that the landing gear could not be extended at all and asked the crew to use the second hydraulic systems, to which Karpov replied that there was basically no pressure from the second system either.
Crash
With the absence of hydraulics, the crew tried to maintain the level of hydraulics by whatever means possible, but their efforts failed when the hydraulics ran out. First Officer Zhavoronkov then told the crew that the aircraft was uncontrollable. The aircraft kept descending, gaining speed tremendously and slightly banked to the right. The pilots desperately tried to raise the nose.
Local residents reported loud rumbling sounds coming from the sky. A tractor driver on the farm saw the aircraft coming towards him at terrific speed. At 12:08 p.m, less than 10 minutes after taking off, the aircraft crashed at a speed of 510 km/h (280 kn; 320 mph) into a dairy farm in the village of Mamony, 15 kilometres (9.3 mi; 8.1 nmi) from Irkutsk airport. The cockpit and the first passenger cabin were destroyed, and the second passenger cabin and tail were propelled 400 metres (1,300 ft; 440 yd) beyond the initial point of impact before disintegrating.
All 115 passengers and 9 crew members on board were killed. A farm building was destroyed; a male occupant was killed, and a female occupant survived with major burns. Additionally, several dozen cattle were killed. A total of 125 people died, of whom only 74 could be identified.
Investigation
In-flight fire
The rapid loss of control was caused by a fire that spread quickly within the No. 2 engine compartment. The rapid spread resulted from the fire's location, and the circumstances that caused it. After the engine completely failed, it exploded outwards, and some pieces sliced the fuel and hydraulic lines within the compartment.
The sequence of events began when the flight crews were starting the engines. The crew faced difficulty with the No. 2 engine, while the others had started normally. During their attempts, they noticed that the No. 2 engine's turbo compressor had spontaneously rotated, which should have happened only had they pressed the air bleeding button, which they had not. When they had successfully started all of the engines, a red alarm light suddenly turned on, warning the crew that the engine starter of the No. 2 engine had reached a dangerous level of rotational speed.
The crews knew the design of the Tupolev Tu-154 and deemed it impossible for such a thing to happen, so they rejected the warning as a false alarm. The light remained illuminated as the speed remained at a dangerous speed; however, the flight manual stated that such an alarm was not a cause for an emergency and would not require immediate action. As the engine parameters remained at normal values, the crew decided to continue for takeoff.
As the thrust lever was set for takeoff power, the rotational speed increased tremendously. After lifting off, the crew turned on the air bleed system for the engines. The air starter then spun intensively until passing 40,000 rpm, far beyond its maximum rotation point. Added with the high temperature of the compartment, the turbine blew apart. The gearbox and turbine shaft exploded, blowing the casing of the No. 2 engine outwards and slicing nearby hydraulic lines and fuel lines. The heat that had been caused by the failure produced flames on the engine's gearbox as the oil that coated the component had ignited. This was fed by fuels and hydraulic fluids from the ruptured lines, resulting in a larger flame. The fire siren eventually sounded inside the cockpit, warning them of the fire.
The crew had tried using all of the Tu-154's fire-extinguishing system and all three stages of extinguishing, but they failed as the fire didn't go out. The engine had failed in a violent manner in which parts of the starter turbine had ruptured the casing of the combustion chamber. The debris pierced the outer casing from the inside, creating a 1 meter opening within the compartment. As the fire was still fed by air, it kept growing instead. Knowing that the fire would grow uncontrollably, the crew decided to turn back towards Irkutsk to land as quickly as possible.
By now, all three hydraulic lines had been damaged by the growing fire, causing the hydraulic pressure to become unstable. The depleting fluids caused the pressure to drop, and the aircraft became uncontrollable. The fire siren eventually went out, either because the fire had grown so large that it had destroyed the electrical circuit or that the fire had been extinguished by itself as it no longer had fuel to feed. The crew could not slow down the aircraft and tried everything to avoid a collision, but the absence of hydraulics caused the aircraft to be not budged by the crew's attempts.
Defective aircraft
Examination of the engines showed that the failure might have been caused by a foreign object inside the air starter, presumably fragments from the air-to-air radiator guide vanes that had fallen into the area. The presence of such an object inside the compartment caused the pressure damper of the engine starter to not be able to close. Pressurised air was constantly supplied into the engine, causing it to spontaneously spin even when the crew had not pressed the button to start it. When the crew lighted up the engine, the already-spinning turbine progressively spun faster until it reached a dangerous level.
When taking off, the alarm didn't sound regarding the engine. Even though there was a small opening which caused constant air supply, the engine was still rotating within the limits as the air bleed valve was not opened by the crew. During the climb, the crew finally opened the valve by pressing the air bleed button on. Immediately, the air starter inside the No.2 engine began to rapidly spun, reaching 40,000 rpm. High rotational speed, added with the increasing heat of the engine itself, caused the air starter turbine disk to break apart.
The engine failed in a violent manner, in which the blown turbine caused the fuel supply pipelines located nearby to be sliced. Hot condition within the compartment caused the fuel to ignite, producing flames inside the compartment. As the explosion of the engine had caused opening within the compartment and the outer casing of the engine, the fire didn't get extinguished and kept growing as it was still being fed by air from the outside. The crew could not contain the fire as the aircraft's fire-extinguishing system was ineffective.
The investigation noted that the proximity of the hydraulic lines to the engine would be classified as a design flaw. The aircraft involved in the accident, the Tupolev Tu-154M, was an upgraded version of its predecessors. In the previous Tupolev aircraft, the hydraulic lines were not concentrated together. In the Tupolev Tu-154M, all three hydraulic lines of the entire aircraft were concentrated on the No.2 engine. The hydraulic pipelines were not made with fire-resistant material and heat-protective screens.
IAC stated that the aircraft's No.2 engine had suffered problems twice prior to the accident. During an approach to Guangzhou, China, the engine suddenly failed and the crew had to do an emergency landing. A complaint was eventually made to the maintenance; however, it was unknown whether the issue was rectified. The investigation concluded that the aircraft should not have been flown that day due to its unworthy condition.