Mick Mansell tells the post-Dunsfold story.
    Hawker Siddeley Hawk Mk50 G-HAWK (ZA101) arrived at the Brooklands Museum in Weybridge, Surrey on 23rd January 2019. This demonstrator aircraft has been donated by BAE Systems and was delivered by road from Samlesbury, Lancashire.
    The Hawk was conceived and designed as the Hawker Siddeley HS.1182 at Kingston-on-Thames (Hawkers) in the late 1960s and early 1970s.

Although G-HAWK was the eighth Hawk built, it was the fifth aircraft in the flight test programme and also the first (and only) Hawk Mk 50. Registered with the CAA as G-HAWK but also allocated the military serial number ZA101, it was first flown by chief test pilot Duncan Simpson from Dunsfold Aerodrome, Surrey, on 17th May 1976 and put to use as Hawker Siddeley’s privately funded Hawk demonstrator and development aircraft.

The equipment fitted in G-HAWK was either loaned free of charge or provided free of charge by the suppliers to support the Hawk sales effort.
    It should be noted that Hawker Siddeley Aviation,Kingston was the only UK company to have built and operated thee private military jet aircraft demonstrators, one for each major type: Harrier, Hawk and Hunter.

G-HAWK’s role was similar to that of its Dunsfold stable mate, the two-seat Harrier Mk52 G-VTOL/ZA250, already being used to promote Harrier export sales to potential customers. The third Hawker demonstrator was the two-seat Hunter G-APUX.
    

G-Hawk At Warton

Toptop toptoptoptoptoptoptoptoptoptoptoptop

Besides appearing regularly at Farnborough and other major air shows, G-HAWK made extensive overseas sales tours including three to the USA (leading to the US Navy’s significant order for the T-45 Goshawk), and several times to Europe, the Middle East, the Far East and Australia.

    This aircraft played a key development role in the Hawk becoming the world’s most successful military jet trainer with over 1,000 aircraft delivered to 18 countries and more than four million hours flown.

At Dunsfold it was the main development aircraft used to clear a wide variety of weapons and external stores for export Hawks with the original TMk1/Mk50 series standard wing and the improved MK60 series standard, and at Warton, for those aircraft which had been upgraded with the wing tip mounted AIM-9L Sidewinder 7 station wing. It was also used in exploring the T-45’s low speed handling and spinning characteristics and by the R&D (research and development) department at Warton as both a ground test and flight test vehicle for development of survivability technologies

    The activities that G-HAWK carried out at Warton commenced soon after its arrival. There it was always referred to as ZA101 after a decision was made to delete it from the civil register.
    ZA101, flown by Graham Tomlinson, and ZH200 (the second single-seat development Hawk) flow by Phil Dye, arrived on 14thNovember 1988 at Warton directly from the Summer 1988 Far East Tour. During this tour to Australia the aircraft visited some exotic places including Brunei, Singapore, Malaysia, Thailand, Indonesia and the Philippines.
    At Warton, the aircraft continued its flight development activities and went straight into a flight test programme for stability and control checks with 5 x BL755 and inboard tanks with and without AIM 9L Sidewinder configurations in support of Hawk 100/200 series contracts. All the heavy weight clearances for the Mk50 and Mk60 series aircraft had been done at Dunsfold but further flight tests were carried out to resolve issues raised by some customers including requirements for higher store release speeds and different dive angles. Hence some of the clearances were revisited and expanded.
    The aircraft then went into the first of a series of spinning and stalling trials in for various export aircraft customers, which continued the initial spinning and stalling trials in the long nose Mk 100 shape at Dunsfold.
    These trials were interspersed with further wing development work for the T-45 programme. Initial flights assessed the effects on approach speeds of various combinations of wing fence and vortex generator arrays eventually reaching the CL max of around 2.0 previously achieved at Dunsfold, but handling characteristics were marginal. Whilst achieving very low stall speeds, these marginal post stall characteristics led to the introduction of the T-45 slats anyway following US Navy trials at the Naval Air Test Centre, Patuxent River, Maryland.
    Typically, during the trials, there would be a change of wing dressing followed by stall testing and then, for the more successful dressings, some spinning. As part of these investigations, a US test pilot from McDonnell Douglas, BAe’s partner in the T-45 programme, flew the aircraft to compare standard Hawk characteristics to those of the T-45 which back in the US was exhibiting adverse yaw in the approach configuration. He was amazed at the difference and really loved flying the Hawk. He went home convinced that whatever was going wrong was not intrinsic to the Hawk but was a feature of the T-45 itself.
    During this period of testing the opportunity was taken to revert the aircraft to its demonstrator role in support of export Hawk marketing activities when it performed a block of 24 flights for the Swiss Air Force 75th Anniversary at Payerne and the Baghdad Arms Exhibition. In this period the aircraft was also used for flight assessment by the Brazilian and Korean Air Forces.
    Following these trials and demonstrations, in July 89 the aircraft was laid up to fit the seven-station wing with wing tip AIM-9L Sidewinders and a new fin with a revised RWR (radar warning receiver) housing. The shake-down flight in this new configuration took place on 27th April 1990.
    The aircraft then embarked on a series of extensive flight test clearance programmes, air shows and flight demonstrations in support of a lucrative and expanding export market for the latest series of Hawk variants, primarily the 100 series. It completed all of the handling trials for all of the configurations and weapons specified by the customers and all of the flutter clearance work. Handling trials included stalling and spinning with symmetric and asymmetric wing tip Sidewinder and Sidewinder firings at up to 6g and 40,000 feet altitude. No problems were experienced during any of these firing trials which confirmed that the revisions to the wing tips for the missiles had not adversely affected the hung weapon capability. At the end of the handling trials the aircraft successfully carried out a take off from Warton with 5x1000 lb bombs and two tip mounted Sidewinders. Again, no problems were encountered.
    During this flight test period up to 8th April 1991, the trials had been conducted with the Adour Mk 861A engine. Then in support of the Mk103 and Mk203 aircraft for Oman, the Adour Mk871 engine was installed and the clearance trials for flutter, handling and spinning were carried out with handling and release clearances for CRV7 rocket pods and SAMP 400 kg bombs.
    Interspersed with clearance trials were more air shows and overseas trips. In September 1990 the aircraft flew a block of 40 flights at the Farnborough air shows with displays and demonstrations for representatives from Indonesia, Venezuela, Chile, Malaysia and UK VIP’s.
    In February/March 1992 the aircraft, flown by Paul Hopkins, embarked on a Far East tour covering three major events. It was ferried to Singapore for the ASEAN/Singapore air show and a Singaporean evaluation. Paul Hopkins carried out the demonstrations and Phil Dye flew the Singaporean Senior Air Force Officers. The aircraft was then ferried to the Malaysian air force base at Simpang, Kuala Lumpur to give the Malaysian Chief of the Air Staff a flight in advance of their purchase of the Mk 108.

The next major stop was Delhi for the Indian Air Force and Navy evaluation. This included a demonstration of the Adour 871 engine performance achieved on ZA101 by Rolls-Royce adjusting the 861 engine installed in the aircraft. Shortly after the return home the Hawk was selected by the Indian Air Force.

    From the time the aircraft was fitted with the new wing in April 1990 to the time it had completed the flight development programmes and overseas tours in support of the 60 and 100 series Hawks in January 1995, it had flown some 400 hours, most of this flying being completed by Paul Hopkins and Phil Dye.
    Having successfully fulfilled its flight development roles for Hawk exports, in mid 1995, ZA101 became surplus to requirements and was transferred to the Advanced Technology Department at Warton and operated out of 31 Hangar on the south side of the airfield. Here it was used by the R&D group as both a ground test and flight test trials aircraft on research activities in survivability and camouflage technologies. These were classified programmes which were jointly funded by the UK MoD and by BAE.

Between June 1995 and September 1995,the aircraft initially underwent ground based radar signature measurements on the Warton stealth test range followed by modifications to the aircraft to install the electronics equipment and associated instrumentation for the infra-red (IR) flight trials. The first shake down flight was on 18th September 1998 in preparation for the trials.

    There were two major programmes in work at this time. The first was an infra-red camouflage system which sensed the background IR radiation behind the aircraft and operated IR radiators mounted around the fuselage and wing to hide the aircraft’s IR signature. Some 12 or so flights were achieved in the September 1998 to June 1999 time period, most of which were in the winter with clear skies to give favourable conditions for the measurements. ZA101 flew behind the BAE Systems owned Jetstream which conducted the in-flight IR measurements. The ground based trials were carried out on ZA01 to assess the effectiveness of various radar absorbent materials for radar signature reduction. The results of these two R&D programmes were made available for application to the Advanced Studies Department new aircraft programmes.
    The modifications to ZA101 were removed at the end of the trial and the aircraft returned to flight test in July 1999, the aircraft finally retiring from flying duties on completion of its last recorded flight on 9th February 2001. The final flight of ZA101 from Warton was made by Archie Neill on 3rd February 2005
    From here the aircraft was transferred to the Apprentice Training School at Warton and then to the new BAE Systems Academy for Skills and Knowledge which opened at Samlesbury in late 2016.
    It became surplus to requirements again in October 2018 and was offered to the Brooklands Museum having been replaced in the Academy by a standard Indonesian Mk53. ZA101,with a surplus Mk53 wing, arrived at the Brooklands Museum in Weybridge on 23rd January 2020.
    During its flying career G-HAWK/ZA101 accrued a total of 2407 flights and 2217 flying hours. Of these, 1903 flights and 1752 flight hours were when the aircraft was based at Dunsfold and 504 flights and 465 hours when it was based at Warton. When at Warton it was flown by 19 different test pilots, by an even greater number when at Dunsfold and by an unknown number of customer pilots from many countries all over the world. This important aircraft was also flown by a NASA astronaut, Pete Conrad, Commander Apollo 12,who was one of the twelve that walked on the moon.
    G-HAWK/ZA101’s work helped to make the Hawker Siddeley Kingston/British Aerospace Hawk currently the most widely used and successful military jet trainer in the world.
    This article was written by Mick Mansell in collaboration with Dave Ward, Phil Dye, Chris Farara and Chris Roberts. Without their help I could not have completed it. Many thanks for all your expert inputs. MM, 4th April 2020.