How Dangerous Was the Problem with the Belavia Aircraft?

(updated) Aviation expert answers.

Filin asked an aviation engineer about the emergency landing of the Minsk-Antalya flight in Moscow.

On July 26, the Belavia plane, flying over the Belgorod region, gave a distress signal. The reason for this was a critical sudden rise in oil temperature in one of the engines. The flight made an emergency landing at Domodedovo airport with the engine turned off.

- How high was the likelihood of a tragic outcome under such circumstances?

- Landing with one engine is not something super scary, - explains the expert on the condition of anonymity. - It is not the number of engines that is important but the ability to adjust the flight speed and landing. One normally working engine is enough for landing. But the plane will need a longer runway than usual (as a rule, large airports have one, huge airbuses take off and land there, which also need a long runway).

A longer runway is needed because, in a normal situation, at the first stage of braking, there is engine braking - reverse (reverse thrust) is activated. And only then the usual brake on the wheels is turned on.

- What could be the reason for a critical sudden increase in engine oil temperature?

- The reasons may be different. For example, low-quality oil with a low flashpoint. Or bad fuel with a very high combustion temperature, which the cooling system did not cope with. The wrong engine mode may have been selected, causing overheating. And a very likely reason - the cooling system did not work well.

- Could the oil temperature gauge have lied?

- Sure. But the sensors do not lie so often, for this, you need a very good reason.

- Could the engine catch fire or explode due to a critical rise in oil temperature?

- No. It would just jam and stall. The engine does not explode because of the oil temperature.

- And the engine could explode because of what?

- The jet engine is quite simple in design. The airflow through the compressor enters the combustion chamber and then mixes with the fuel, ignites, and flies into the turbine, accelerating there and pushing the engine.

An explosion can be in the combustion chamber when, for example, there is too much fuel. If a bird or any other foreign body enters the engine. If something other than fuel and air gets in, the composition of the fuel-air mixture is disturbed, foreign bodies burn faster and spoil the flow with all sorts of particles such as coals, something unburned, which, in turn, breaks the turbine blades.

The engine doesn't just explode in cruising flight. There's not much to explode.