The helicopter that crashed in Kyiv, in which numerous other people died on the ground in addition to the Ukrainian Interior Minister and his deputy, is a European Airbus H225 helicopter.

This 11-ton class helicopter is based on the AS332 Super Puma, of which well over a thousand have been manufactured, and which was first manufactured by the French company Aérospatiale and later by the European helicopter company Eurocopter, now known as Airbus Helicopter, since 1978.

The H225 is available in a civil and a military variant as the H225M.

Technically they are identical from their starting point.

Both are powered by two Safran Makila 2A1 turbines, each with a take-off power of 2100 hp.

The H225 is considered to be versatile: passenger or cargo transport, search and rescue, aerial work or firefighting using suspended water bags.

The H225 is something like a flying Unimog, it can be used universally.

It also has a modern autopilot that supports the crew and is more powerful than the autopilot on a commercial airliner.

The H225 can not only automatically hover over a defined point, but also fly backwards.

The autopilot supports the crew, which consists of one or two pilots.

It is common for a helicopter of this size and complexity to be flown by a crew of two.

The H225 is also one of only a few helicopter types that is suitable for all weather conditions.

It has a de-icing system for its rotor blades.

This prevents ice from forming on both the five rotor blades and the four-bladed tail rotor system at low temperatures.

In the worst-case scenario, this ice would impair the aerodynamics of the machine to such an extent that the helicopter could crash.

This is prevented by the built-in de-icing system.

Only medium-sized to heavy helicopters have such a system.

In addition, an H225 has so much power that even if one engine fails, it could continue to fly with just one engine running for a safety landing at the nearest suitable area.

Even in the unlikely event that both turbines fail at the same time, the helicopter will not crash: the pilot then has to perform an unpowered autorotation to make an emergency landing on the nearest free piece of land.

Such maneuvers are practiced again and again by crews of these heavy helicopters.

Any problems with the gearbox

However, the accident record of the AS332/H225 is not spotless.

The crash of a machine in the North Sea in 2013 indicated possible problems with the main rotor gearbox.

For a few days in the summer of 2013, all helicopters in this series were therefore grounded by the British Civil Aviation Authority for North Sea operations.

However, the European Aviation Safety Agency EASA released the helitype for flight operations again in June 2013.

On April 29, 2016, disaster struck.

An H225 crashed while returning from a drilling platform near Tuorey near the Norwegian city of Bergen, none of the 13 people on board survived.

The complete main rotor had become detached from the helicopter.

A videographer captured the dramatic moments.

As a result, the Norwegian and British aviation authorities, and on June 2, 2016 EASA as well, issued a temporary flight ban for this type.

This was later withdrawn after consultation with the manufacturer Airbus Helicopter and additional requirements for maintenance and further technical instructions for the operator.

After EASA, the Norwegian and British aviation authorities released flight operations for the AS332L2S and H225S series again in the summer of 2017.

Investigators from the Ukrainian Air Accident Investigation Board, presumably supported by experts from the manufacturer Airbus Helicopters, are now going to look for the cause of the crash in Kyiv.

A black box like on an airplane that records all flight data would be rather unusual on board the helicopter.

The investigators will therefore probably concentrate on a possible technical defect, pilot error or weather as the cause of the fatal crash.