de Havilland DH125

Aircraft Overview:

Designed at Hatfield, and first flown there in 1962, the de Havilland DH125 executive aircraft was the jet successor to the Dove. It was made simple for low cost e.g. with no thrust reversers or engine silencers, and low wing sweep with no leading-edge flaps or slats. But it had the essentials of a ‘mini-airliner’, including navaids, weather/collision radar and a pressurised cabin of larger cross-section for more comfortable accommodation. The rear mounted engines gave less cabin jet noise, avoided engine foreign object damage (FOD), left the wing clear for double-slotted flaps, and allowed a short undercarriage. Other features include:

• a one-piece wing mounted below the fuselage (and faired fore-and-aft), leaving no internal spars for passengers to step over;
• a ventral skid to aid emergency wheels-up landings;
• a cockpit cap fairing to reduce buffeting;
• a plug type entry door, moving inwards then up and over;
• accommodation for two crew and six passengers with a small galley and luggage space forward, and a lavatory at the rear;
• a fin fillet ram air intake for cabin air conditioning;
• extra fin area added above what had been a ‘T’-tail;
• porous leading edge strips for fluid de-icing;
• mainwheels left exposed when retracted;
• and chined nosewheel tyres to deflect spray sideways below the engines.

Aircraft Specifications:

Power Unit: Two 3,000 lb.s.t Bristol Siddeley Viper 520 Turbojets

Wing Span: 47 ft (14.34 m)

All-Up Weight (A.U.W): 20,000 lb (9,072 kg)

Max. Speed: 484 mph (778 kph)

Ceiling: 38,000 ft (11,580 m)

Range: 2,000 miles (3,218 km)

On Display at the Museum:

The Museum’s DH125 (G-ARYC) was the first production aircraft, built at Chester in 1963 and used for Viper engine development, later for liaison between Filton and Toulouse for Concorde. It was moved to the Museum in 1979. In its various later guises (with Hawker Siddeley, Beechcraft, British Aerospace, Raytheon) the 125 became one of the World’s most successful business jets.

This was the third DH125 (Manufacturing Serial Number 25003) but was the first to be completed at the Chester factory.  It was also the first to be built to the Series 1 production standard.  MSNs 25001 (G-ARYA) and 25002 (G-ARYB) were completed at Hatfield with the major components having been shipped from Chester.  These first two aircraft, however, we’re essentially prototypes, differing substantially from the third and subsequent aircraft.

G-ARYC was built in 1962/63 and first flew on 12th February 1963.  On completion of flight testing she began her career in July ’63 with Bristol Siddeley, being used to test and develop the relatively new Viper 520 Series engine, rated at 3,000lb thrust.  This was to be the standard for the Series 1 aircraft (‘YA’ and ‘YB’ started life with the 2,500lb thrust 511 Series).

In early May 1964 ‘YC’ visited 16 countries, covering over 5,000 miles, in one day (19hrs 32mins) thus demonstrating the robustness of the 125’s design and its ability to deal with an intensive operating schedule.  Later, when Bristol Siddeley became part of Rolls Royce, ‘YC’ was one of four aircraft used as communications aircraft between Filton and Toulouse for the Concorde’s Olympus 593 engine.

DH125 at The de Havilland Museum, London Colney, UK. #DH125 #deHavilland #museum #exhibit #theta360 – Spherical Image – RICOH THETA