Aviation Specials — F-22 Raptor (2017)

and we said, ‘no, we’ll make a pact with

you. When the throttle is in the idle-to-

maximum thrust range, we want the

engine to spool up. When the engine

throttle is in the off position, we don’t

want the engine to run’. We also said that

if we were flying the F-22 at high altitude

and an engine flames out we know we

cannot restart it at that height. We said:

‘Our promise to you is that that we’ll

put the airplane back into the airstart

envelope and when it is, you must make

the engine run normally’. They realised

that at extremely high altitude that they

could still keep the combustors ignited.

Not enough to get the engine up to full

speed, but enough to keep the engine

warm and keep the fire lit. All the pilot

had to do is point the nose over and get

the jet down to the correct altitude and

airspeed, and then the engine would start

automatically. If the engine can’t start

on its own, the APU will automatically

come on to boost the engine RPM.

Basically, it will go through multiple start

possibilities to get the engine running. All

the pilot has to do is get the engine in the

‘operate range’.’

So much of the Raptor is software-

driven. It features several types of

computers: flight controls, mission,

avionics, radar, stores management,

plus Lockheed Martin added a vehicle

management systems controller. This

looks after hydraulics, fuel, and oxygen

and co-ordinates all those subsystems.

RAPTOR^21

16-27 Metz First Flight C.indd 21 28/09/2017 14:53