Target-type thrust reversal

[2] As early as 1963, an invention called "two part thrust reversal" appeared with a similar deflector door design.

In this case airflow passes through the inner surface and travels frontward to provide force opposite to the heading of the aircraft.

When stowed, the doors seamlessly connect to the rest parts of the engine to provide a streamlined outer surface.

[6] However, this result is obtained with a cowl to attach air flow in a 7° angle and a large enough "target" (deflector door) installed.

A considerable proportion of Russia-made aircraft like the Tupolev Tu-154 and Ilyushin Il-62 (unlike the VC-10 which has a Clamshell type reverse thrust) have this feature.

[8] The Douglas DC-8, on the other hand, is qualified to use thrust reversal anytime in flight for speed adjustment.

Therefore, the airflow from the core part must be blocked in order to produce sufficient reverse thrust.

The inventors state that this design can reduce the weight of the engine and the maintenance cost since the system is more simplified.