Variable Stability

(Or making perfectly good aeroplanes fly badly)

CAe have been building and supporting bespoke, ‘fly by wire’ systems to demonstrate variable stability in conventional aircraft for the Empire Test Pilots’ School for over 35 years.

The first project was the Beagle Basset

And this aircraft is still in service.

The Advanced System TRaining Aircraft (ASTRA) Hawk continues to be ETPS’s primary teaching tool.

CAe converted a Hawk T Mk 1 to Variable Stability aircraft when flown from the front seat to provide ETPS with a handling qualities assessment trainer and research vehicle.

• CAe Designed and Built Flight Control Computer
• CAe System Design and Installation
• CAe Software Engineering
• Steady Programme of Improvement in collaboration with QinitiQ Boscombe Down:
• Updated In-Flight Monitor Algorithms
• Improved Trimming for artificial feel in the Variable Stability System
• Continuing PDS for at least another 10 years.

V/Stol Advanced Aircraft Control (VAAC) Harrier

It was the first aircraft to carry out a fully automatic, vertical landing on an aircraft carrier; it has been used extensively for development trials on the Joint Striker Fighter.

CAe involvement has been:

• Conversion of Harrier T Mk 2 to Fly By Wire from the rear seat (In partnership with DERA now QinetiQ Bedford)
• CAe Designed and Built Flight Control Computers
• CAe System Design and Installation
• CAe Software Engineering of Safety Monitor
• CAe continuing support in system maintenance
• Steady Programme of Improvement and research:
  • New Inceptors
  • Data Capture and Recording
  • Navigation Aids
  • Preparation for carrier operations

In this case it’s not making the aircraft fly badly, but making it fly very well even without any pilot input.

ASTRA at Cranfield