An-124 Runway Overrun
On the Friday the 13th of November 2020, an Antonov An-124-100 had a very unlucky day.
The Antonov An-124 is a Soviet designed and Ukrainian manufactured four-engined aircraft. It’s a massive beast with a maximum take-off weight of 405,000 kilos. The An-124 was the heaviest cargo aircraft of its time and is still the largest military transport aircraft in service. There are fewer than two dozen An-124s in the world.
This two minute video gives a good introduction to the history of the An-124:
The important thing to know in this case is that the An-124 is huge and a wonder to behold.
This particular Antonov, registration RA-82042, has been flying since 1991.
It was operated by Russian cargo carrier Volga-Dnepr Airlines who have a fleet of twelve Antonov AN-124s, five Boeing 747-8F and five IL-76TD-90VD, all aircraft targeted at oversized and heavy cargo. Volga-Dnepr is the only company in the world with an AN-124 simulator.
Here is a video of the same aircraft departing from Munich:
About a month after that video was taken, the An-124 was flying as flight VI4066, carrying 84 tons of automotive spare parts from Seoul, South Korea to Vienna, Austria, with an overnight stop at Novosibirsk-Tolmachevo Airport in Russia. The aircraft arrived at Novosibirsk at late afternoon on the 12th of November. The following morning, the aircraft taxied to runway 25 for a noon departure with six flight crew, eight other crew and the cargo.
The An-124 took off normally and entered a right-hand climbing turn. As it reached about 1,500 feet, about 3.5 nautical miles from the runway, the huge aircraft suddenly disappeared from radar and did not respond on the radio.
The number two engine (left-hand, inside) had suffered an uncontained failure, in which an engine violently separates (essentially explodes), with engine debris exiting at high speed. The debris punched through the fuselage, the landing gear and the wings. Shrapnel went straight through the top of the fuselage at the right side. Small metal fragments from the engine sheered through cabling, taking out the aircraft’s electrical supply. The transponder and the radio failed, causing the aircraft’s sudden “disappearance”.
The flight crew immediately focused on recovery; they had lost their instruments but the An-24 was still controllable. They were unable to make visual contact with the tower as they came in heavy and slow for runway 25 with no margin for error.
The An-142 touched down perfectly but they had no means to slow down the aircraft: the brakes, spoilers and thrust reversers had all failed with the damage from the engine failure.
The nose-wheel collapsed as the An-124 ran off the runway. The aircraft thundered on, coming to a halt about 300 metres (1,000 feet) past the end of the runway. No one suffered any injuries unless you count the poor An-124.
One large fragment, likely to be from the engine’s fan disk, was found in a warehouse near the airport where it had crashed through the roof. Part of the cowling was found on rough land about five kilometres from the airport.
— Breaking Aviation News & Videos (@breakingavnews) November 13, 2020
Volga-Dnepr grounded the eight remaining An-124s in their fleet over concerns as to what caused the engine, produced by Ukrainian manufacturer Motor Sich, to fail.
Konstantin Vekshin, the Group Chief Commercial Officer of Volga-Dnepr, said that they are starting work on the remaining An-124 in the fleet:
The experts are starting inspections soon and we are in daily contact with the Russian aviation authorities and Motor Sich. Everyone is working on it now. It’s been a serious test for all of us, but everyone has been very positive.
It takes about an week to complete a detailed inspection of an engine and Volga-Dnepr own sixty of the engines. The first An-124 came back into service on the 29th of December, leading Vekshin to happily announce that they managed to restart the An-124-100 operations before the end of the year.
The West Siberian Transport Investigation Department, part of the Investigative Committee of the Russian Federation, is investigating.
I often treat this as the end of the sequence, at least until the final report is out. But of course, the situation isn’t finished just because the runway is clear and everyone has safely evacuated. There’s still the issue of moving the aircraft, a particular challenge with a monster like the Antonov An-124.
Even at the best of times, towing the An-124 out is not a minor operation. But this was not the best of times: upon departing the runway, the aircraft had dug deep into the ground. It being November in Russia, the ground then froze.
Airport authorities brought in the military who came with two BREM-1 tanks: armored carriers built on the chassis of the T-72 battle tank. Finding that the main landing gear was still stable, they were able to connect a cable to the An-124’s cargo hold and used the two tanks to pull the plane backwards out of the frozen ground.
Bystanders said that after three hours, the aircraft had only moved one metre.
However, as you can see on this video, perseverance won the day.
The An-124 is now on a hard surface and awaiting inspection. It has not yet been established if it will remain in service.