Aircraft Engineering Systems Trainer for the Harrier GR7

Citation

(1999), "Aircraft Engineering Systems Trainer for the Harrier GR7", Aircraft Engineering and Aerospace Technology, Vol. 71 No. 5. https://doi.org/10.1108/aeat.1999.12771eaf.008

Aircraft Engineering Systems Trainer for the Harrier GR7

Aircraft Engineering Systems Trainer for the Harrier GR7

Keywords: Harrier, Engineering, Training, Aircraft, Simulation

The Royal Air force has successfully completed acceptance tests on an Aircraft Engineering Systems Trainer (AEST), manufactured by Brookhouse Paxford of Huntingdon (Plate 4).

Plate 4 The Aircraft Engineering Trainer for the Harrier GR7

Installed at RAF Wittering, the AEST represents the forward section of a Harrier GR7. The cockpit is faithfully replicated, both internally and externally, with many PC-driven instruments and controls fully functioning.

The AEST was designed to train power plant and weapons technicians assigned to Harrier Squadrons 20R (Operational Conversion Unit) and 1 (F), both based at Wittering. Many training programmes which previously involved real aircraft are believed to be transferring to the AEST, with benefits claimed in terms of reduced safety risk to personnel and equipment, simplified scheduling and lower operational costs.

Brookhouse Paxford secured an MOD contract after working closely with project staff at RAF Wittering to produce a formal Statement of Requirement. In addition to the functional requirements of the simulator, its mobility within the training area and ease of transportation were essential design considerations.

The cockpit was constructed in fibre composite, using tooling generated from engineering drawings for the GR7, and was mounted on a steel space frame. This combination provides adequate rigidity and strength while minimising the weight of the trainer to aid mobility.

The RAF's training objectives determined the degree of authenticity of each of the instruments, controls and cockpit fittings. These vary from simple facsimile models to fully interactive, three-dimensional models which, where appropriate, included aircraft standard parts and materials. This approach is thought to guarantee high value in terms of training capability, while employing a low cost value engineered hardware solution.

The AEST has two operating modes. Engine ground running is simulated by reproducing "as aircraft" conditions and response to throttle and switch inputs, including all warning conditions and indications. In weapons configuration the AEST provides for training on the use and maintenance of ejection seat and canopy. In addition, the AEST fulfils a subsidiary role as a cockpit familiarisation trainer.

The active instrumentation is interfaced to a multipurpose colour display unit in the cockpit and to repeater instruments and a VDU on an instructor's remote console. The instructor is therefore able to monitor the student and can also introduce technical problems from a menu of fault modes.

An audio/intercom system reproduces engine sounds from starting to shutting down, in addition to issuing audio warnings and allowing communication between student and instructor. The cockpit is also equipped with a secluded CCTV system comprising two fixed cameras and two remotely operated pan-and-tilt cameras.

The role of the simulators in aviation has so far been largely restricted to pilot training. However, the use of simulators is said to be steadily growing to encompass many other aspects of aircraft operation, particularly in military applications.

One of the fundamental benefits of flight simulation, the elimination of risk to personnel and hardware, is also relevant to wider training activities, from maintenance to fuelling and armament loading. Equally, the economic arguments for off-line training are gaining strength with the growing costs of personnel training and the complexity of aircraft systems.

The initial purpose of the AEST project was to provide a Harrier GR7 escape systems trainer for pilots and ground crew. It was clear, however, that with the possibility of full spatial representation and a computer system, the project could ultimately yield a much more valuable resource.

In view of their frequency and critical nature it is vital that engine ground runs are thoroughly rehearsed. A ground run is necessary in numerous instances, for example following engine maintenance, starter motor replacement or for testing systems such as hydraulics and cockpit conditioning.

With engines costing in the region of £1.5 million, any fault developing during a run must be dealt with quickly and expertly to minimise damage and, in extreme cases such as a jet pipe temperature runaway, to prevent a total engine loss.

In engine run simulation another key advantage is thought to be the potential time saving, compared with training on real aircraft. In practice, Harrier engines are tested with the aircraft safely secured on a "tie down pan". This not only stops the aircraft becoming airborne during an engine ground run but also directs the exhaust clear of the ground crew. At Wittering, towing an aircraft from the apron to the tie down pans at the regulation pace can take up to 40 minutes.

Further details are available from Brookhouse Paxford. Tel: +44 (0) 1480 453537; Fax: +44 (0) 1480 413125.