A mock-up was made at Dunsfold and the idea was received favourably by the RAF  but the MoD maintained that the Hunter would be phased out of RAF service in four years! HSA were unwilling to pursue the idea in case it damaged potential P.1127 sales so this idea, to modernise the Hunter weapons fit, lapsed.

However, in 1976 David met Bill Weetman, recently back from Singapore where he had been working on new armament installations for the Singapore Ministry of Defence Hunters, including Sidewinders, but this time underwing. Bill said they needed a test pilot and David jumped at the chance. After a quick trip with the RAF on the Hunter TMk7 he moved to Singapore in 1977 where the air force operated single-seat FGAMk74 Hunters in the fighter/ground attack role and FRMk74A/Bs in the fighter reconnaissance role. For training there were TMk75/A two-seaters.

Lockheed Aircraft Services Singapore (LASS) had the contract to enhance the weapon capability of the Hunter. This included the fitting a US 'triple ejector rack' (TER) under the Hunter fuselage for bombs up to 1000 lb, an additional pair of underwing pylons inboard of the drop tanks for Sidewinders, a Ferranti Isis gun-sight, a Decca TANS navigation system and three alternative reconnaissance packs, in lieu of the gun pack, containing different camera and IR linescan arrays. AIM-9 Sidewinders on LAU-7 launchers, LAU-10 Zuni rocket launchers, 1000 lb bombs, BL755 cluster weapons and US Mk82 500 lb streamlined bombs were to be carried in various combinations, with and without drop tanks.

TERs would also be fitted to the outboard pylons for twin carriage of rocket launchers, 500 lb bombs and BL755s. The heaviest combination to be cleared was 6 BL755s plus 2 AIM-9s with 230 gal drop tanks, giving a take-off weight of 27,400 lb. David wrote the flight test programmes to clear these equipments and configurations, conducted all the test flights and wrote all the reports and the Pilots' Notes.

LASS had no flight test experience at all. Their managing director even asked why it was necessary to do all this flying; didn't David trust their engineers?! There was no test instrumentation fitted so David requested a voice recorder; LASS put it under the ejector seat, so David bought a commercial mini tape recorder and got it fitted it in an accessible position. King non-Milspec light aircraft instruments, including an attitude indicator with a 60 degree bank limit, had also been fitted by LASS. Clearly, these had to be changed so David had to redesign the instrument panel.

Eventually the flying got under way over the South China Sea in high humidity and 30 deg C temperatures, with a chase Hunter. The programme was successful and the Singaporeans operated their Hunters until the early 1990s. Eventually they were sold to private owners in Australia, New Zealand and the USA.

The 'Boxer', or Land Development Aircraft (LDA) had its roots in the idea of a Design Liaison Engineer at Dunsfold, David Carter, who thought that an inexpensive utility and crop spraying aircraft should be designed for use in the countries of the less developed world; an "aerial Land Rover". David (L) believed that a large cg range would be necessary for maximum flexibility of loading and this led him to the tandem wing layout, as experimented with by George Miles with his M35 Libellula and twin engined M39B aircraft in the mid 1940s. Besides the larger cg range the tandem wing offered safe stalling and excellent pilot vision.

To test his idea David made a number of tissue covered balsa models with different wing layouts. He settled on a parallel flat sided, rectangular cross section fuselage with a nose cockpit and low mounted adjustable foreplane with flap. At the rear was a high mounted, strut braced, wing, with outboard ailerons/elevators and inboard flaps/elevators, with fins and rudders inset from the tips. Twin undercarriage legs were fitted, fore and aft, the front wheels being steerable through an Akerman steering geometry derived from the Lotus 7, so that the aircraft could be manoeuvred over a detachable payload container to be winched up into the centre fuselage.

The parallel chord, constant section wing panels and foreplane were the same, as were the control surfaces and flaps. The whole design sacrificed visual and aerodynamic elegance for functional practicality. It was designed for easy manufacture in the 'third world'. With the aid of Roger Dabbs, who did the stressing and Type Record, John Quinn and Alan Daffey, a 70% proof-of-concept aircraft was designed and then, with the agreement of John Lidbury, built in a Nissen hut at Dunsfold by David and George Smith from Dunsfold's Production Department.

The LDA 01 aircraft, registered G-AVOR was moved to BAC Wisley and made its first flight, powered by an 85 hp Continental C85, on August 24th, 1971. David found that his creation was fine longitudinally but there was no rudder feel, turn entry was difficult and low speed directional stability was weak. Adding bungee and aerodynamic balances to the rudders helped. Support from BAC included wind tunnel tests and development to ensure that the foreplane stalled first. This also showed that vortices from the foreplane disturbed the wing flow leading to the fitting of wing fences. Wing tip mounted fins were also found to be better and were to be a feature of the full scale aircraft.
 
Flight testing continued at Hurn where, when ballasted to forward and aft cg positions, the wide range proved to be even better than expected; four times greater than a conventional aircraft. The LDA 01 also proved to be highly manoeuvrable. In 1975, with a 160 hp Lycoming engine installed, David took it to the Paris Air Show where, painted half in camouflage and half in civil livery, its performance was interrupted by a swarm of bees settling on the cockpit requiring the attention of the airfield fire brigade! In 1976 the aircraft appeared at the SBAC Show at Farnborough.

The full scale production aircraft was to have wing-tip fins and rudders, a tricycle undercarriage and large, side loading doors. However, this was not to be; the project was killed when  the LDA 01 was destroyed when the Optica hangar at Old Sarum, housing the aircraft, was attacked by an arsonist.

After a short film the vote of thanks was given by Roger Dabbs who said that it was David's drive, enthusiasm, charm and character that led to the successful design and flight testing of this unique aircraft. The audience responded with hearty applause.