Related Pages : 

Keeping the Hawk flying

The following article appeared in the 2000 edition of The Royal Air Force Yearbook, a highly recommended read for all those interested in the RAF.

This magazine is published by the RAF Benevolent Fund Enterprises.

Many thanks to the editor of the Yearbook (Peter March) for permission to use this piece.

The article was written by Kev Storer.

RAF Yearbook

Kev Storer takes a look at the steps being taken to keep the RAF's fleet of Hawk advanced training aircraft in active service.

On the 21 August 1974, the Hawker Siddeley (now BAe Systems) Hawk made its maiden flight at Dunsfold, Surrey. This event, now seen by many as a milestone in post-war British aviation history, saw the birth of an impressive legend. Arguably the most successful jet-powered training aircraft ever built, the Hawk has been further developed into a single-seat variant and a navalised version, the US Navy T-45 Goshawk. Moving from its original design as a trainer, with limited weapons training capabilities, the now heavily armed Hawk has successfully entered the competitive light-attack and lightweight fighter market and continues to be a world-beater.

As the original customer for the Hawk, the RAF intended that the aircraft would replace the Hawker Siddeley Gnat T1 in the jet trainer role and the Hawker Hunter T7 in the tactical weapons training role. It took delivery of the first in-service aircraft at RAF Valley on 4 November 1976 - an association that continues to this day. It was during the production run that a requirement for some aircraft to be in the pure flying training role was decided, this being facilitated by the removal of the aircraft's weapons control boxes. The capability to refit these boxes was maintained and once 'converted', the aircraft were referred to, by the RAF alone, as Hawk T1W aircraft. Additionally, a later weapons system modification introduced a Sidewinder capability to 88 aircraft, the aircraft being redesignated Hawk T1A. During the winter of 1979 and 1980, the Red Arrows replaced its Gnats with Hawks and during the summer of 1980 undertook its first public displays using the new type.

Originally, the Hawk was designed for a life of 6,000 flying hours (approximately 20 years) and 15,000 landings. However, in 1985 it was decided to maintain the current Hawk fleet in-service until 2010 - initially this meant a programme to re-wing many of the aircraft with high-lifed wings. The different usage of aircraft - in the flying training and weapons training roles; the Red Arrows; No 100 Squadron at RAF Leeming; and FRADU at RNAS Culdrose - has meant some aircraft have become high-fatigue lifed and others high-houred. During the early 1990s, it was evident that the majority of the fleet would not reach the required out-of-service date and therefore a series of Life Extension Programme (LEP) studies were undertaken to try to extend the aircraft's life to 10,200 flying hours and 25,000 landings.

As part of the LEP the re-wing programme was extended to cover all RAF Hawks. In conjunction with the other component manufacturers, BAe started looking at the aircraft structure and all the components fitted to the aircraft. This involved re-commissioning the previously completed fatigue test at BAe Brough and examining and testing a sample of all the aircraft's components to ascertain whether they could reach the ultimate required life. The life extension would allow the aircraft to fly beyond it's design life of 6,000 flying hours but would require a detailed examination of the aircraft structure to a pre-defined schedule to be carried out. Once the work has been carried out by 'A' Flight No 6(Eng) Squadron at DARA St Athan, the aircraft will be returned to their respective units.

Moreover, the results of the fatigue test predicted that many of the aircraft would show signs of damage in the rear and centre fuselages before the out-of-service date was reached. Therefore, a modification programme to replace the rear and centre fuselages of 80 aircraft was initiated. This modification programme, titled 'Mod 2010' or the 'Fuselage Replacement Project (FRP)', will see this batch fitted with a Mark 65A series centre and rear fuselage. This new section of fuselage will incorporate all the fatigue enhancements made by BAe Systems from its experience in developing its later series of Hawks. The modification programme is being undertaken by BAe Systems, with 'D' Flight No 6(Eng) Squadron at DARA St Athan acting as a sub-contractor, responsible for the strip-out and rebuild. Initially the aircraft are flown to St Athan to have the wing, latest standard tailplane, fin, engine and all components removed from the fuselage. The fuselage is then transported to Brough where it is 'split'. The 'split' utilises the transport joint behind the cockpit rear-pressure bulkhead where, during the original build, the cockpit and the separately assembled centre fuselage were mated. The front cockpit is then joined to the new section of fuselage in the appropriate jigs at Brough and returned to St Athan for rebuild. Before their refit, all of the components are inspected and replaced where necessary. The aircraft will then be returned to the fleet without a change in aircraft designation.

In addition to extending the life of the aircraft, the weapons training role of the aircraft has been enhanced with the addition of a Gun Sight Video Recording System (GVRS). The system comprises a video camera that films the view through the pilot's Head-Up Display (HUD) and records it onto videotape instead of 'wet' film, as is currently used. This is similar to the systems already fitted to the Jaguar, and being introduced to the Tornado GR1 and GR4. Unlike the original system, GVRS will allow instant playback of the weapons aspects of the mission during the post-sortie debrief, thereby eliminating the time normally taken to process the HUD camera film. As the image quality is greater than the wet film, and the system has shown a higher level of reliability, the system will reduce the number of sorties required to pass the weapons training phase, saving flying hours and fatigue life. The system is planned to be fitted to aircraft that will then operate from Valley and the Tactical Armament Facility (Hawk) Detachment (TAFHDET) at St Athan. Having a permanent detachment of eight Hawks from Valley at TAFHDET reduces the aircraft transit time to the Pembrey weapons range, enabling a higher sortie rate to be maintained.

The recent upgrades programmes seen in the Jaguar and Tornado - in particular the introduction of advanced cockpits - and the existing Harrier GR7 'glass' cockpit, are seen by many to be a quantum leap from the 'dial' cockpit of the Hawk. The introduction into service of the Typhoon, with its state-of-the-art cockpit, will further widen this technology gap. The later marks of the Hawk, in particular those purchased for the NATO Flying Training Course, the Australian Lead-In Fighter and the South African aircraft have a 'glass' cockpit. This is in conjunction with the longer nosed mark of aircraft which offers greater space for avionics, support trays and cooling associated with such a cockpit. The USN has achieved a 'glass' cockpit upgrade with its T-45Cs and has the capability to retrofit this cockpit into its T-45As. It is felt that such a cockpit would allow students a smoother transition from their advanced jet training to the Operational Conversion Units. They will have aircraft with advanced cockpits and will save simulator time and flying hours that would otherwise be used in familiarisation of the advanced cockpits.

The future of all RAF flying training is currently being reviewed, with a view to defining the training requirements of future generations in terms of future aircraft types, both in the training role and at the front-line. This project will define the role, and broadly speaking the specification, of any future training aircraft and the programmes required to support them. It is likely that any future jet training aircraft will involve an aircraft of similar capability to the Hawk. The absence of any other aircraft, either currently available or in the design stage by either Britain or the USA suggests that the next RAF jet trainer will be a Hawk derivative. It is felt that any future 'Hawk' would be similar to the Australian Lead-in Fighter, but would probably have an up-rated engine, a glass cockpit that can be configured as any future RAF fast jet aircraft, together with an enhanced weapons training capability.

The procurement and fit of new wings, tailplanes and rear fuselages will ensure that the structural elements of the aircraft will withstand the rigours of pilot training and opens the possibility of a cockpit upgrade, which could help the RAF's Hawks to remain technologically compatible with any current and future RAF aircraft. Notwithstanding any glass cockpit upgrade or future purchases of Hawk-derived aircraft, it is fitting that as the Hawk's initial customer, the RAF Hawk fleet is set to continue well into the second decade of the millennium.