The American military transport aircraft C-17 Globemaster III is operated from 1993 of the year. Today it is in service with the US armies., Great Britain, Canada and Australia.
Almost all characteristics of the aircraft have been disclosed to date.. However, thanks to a recent video from Squadron # 99 RAF became known, as they say in the West, about one more "special" ("Unique") transport property, namely – the ability to deploy thrust reversers on their engines directly in flight, to ensure a quick descent from the existing height.
Usually C-17, like most planes, uses reverse thrust to deflect airflow up and forward, which contributes to more effective braking when landing. Wherein, thanks to this function, the transporter is able to shorten the distance, which he needs to stop completely, to 900 meters and even less, allowing the aircraft to operate relatively short runways.
On the ground, when the engines are idling, thrust reversers also redirect jet flow away from the rear of the aircraft, which is especially useful when loading or unloading over a ramp.
Regarding the use of reverse engines in the air, it provides the fastest possible descent of the aircraft from cruising altitude. So, in the description of the video from the squadron No. 99 Unknown, that during the recent maneuver, dubbed Reverse idle tactical descent, the plane descended from 9 000 meters to 1500 meters in just two minutes. At the same time, the military claims, that for the C-17 this indicator is not the limit of possibilities.
As soon as thrust reverse engages in flight, pilots ensure that the descent rate of the transporter is maintained, adjusting the position of the aircraft.
Low nose position, necessary to maintain speed, is part of the maneuver, providing a high rate of descent
– explained in the 99th squadron – the only C-17 operator in the RAF.
Although British Air Force Command approves, that the aforementioned maneuver is unlikely to be applied in emergencies. However, it can be assumed, that this "special" property of a transport aircraft could be useful for a sharp decline during penetration into enemy airspace or even landing at airfields, located in enemy territory.