Airspeed Ambassador

The Airspeed AS.57 Ambassador was a British twin piston engined airliner that first flew on 10 July 1947 and served in small numbers through the 1950s and 1960s.

Design and development
The Ambassador had its origin in 1943 as a requirement identified by the Brabazon Committee for a twin-engined, short to medium-haul replacement for the Douglas DC-3. Airspeed Ltd. was asked to prepare an unpressurised design in the 14.5 ton gross weight class, using two Bristol Hercules radial engines. In 1943 the company duly set up a dispersed design office in Fairmile Manor at Cobham in Surrey.

By the time the British Ministry of Aircraft Production ordered two prototypes from Airspeed, immediately after the end of the Second World War, the design had grown substantially. The Ambassador would be pressurised, have more powerful Bristol Centaurus radials, and have a maximum gross weight of almost 24 tons.

The revised design offered seating for 47 passengers and, having a nose wheel undercarriage, looked more modern than the DC-3s, Curtiss Commandos, Avro Lancastrians and Vickers Vikings that were common on Europe's shorter airline routes. With three low fins and long pointed nose it shared something of the character of the larger transcontinental Lockheed Constellation.

Great efforts were made to reduce drag, to improve performance and cruising efficiency. The engine nacelles were first designed with inwardly opening louvres for exhaust gases and cooling air, rather than the usual outwardly opening "gills". However, these proved inadequate to cool the engine, and the gills were reinstated.

Operational history
Three prototypes were built, the first registered G-AGUA was first flown by George B.S. Errington from Christchurch on 10 July 1947. British European Airways (BEA) placed a £3 million order for 20 aircraft in September 1948, and operated them between 1952 and 1958, calling them their "Elizabethan Class" in honour of the newly crowned Queen. The flagship of the fleet was G-ALZN, appropriately named "RMA Elizabethan". The first "Elizabethan" scheduled flight was from Heathrow to Paris Le Bourget on 13 March 1952 and the type later also served the key UK routes. An Ambassador appears in the 1953 film Innocents in Paris. By December 1955 the "Elizabethan Class" had reached 2,230 flying hours annually, per aircraft, the highest in BEA's fleet. However, the last Elizabethan scheduled service for BEA was operated in August 1958, and the type was replaced by the Vickers Viscount.

After disposal by BEA, the type helped to establish the scheduled and charter flight operations of Dan-Air, an important airline in the development of package holidays. The type was also used in the UK by Autair and BKS Air Transport. Second-hand Ambassadors were flown for short periods by Butler Air Transport (Australia), Globe Air (Switzerland) and Norrønafly (Norway).

The second Ambassador 2 G-AKRD was used by the Bristol Aeroplane Company from 1953 for the flight testing of the Bristol Proteus 705 turbine engine. From March 1958 G-AKRD was used by Rolls Royce in proving the Tyne turboprop. The first Ambassador 2 G-ALFR was used from 1955 in the development trials of the Napier Eland turbine engine.

The popularity of this aircraft, with its pressurised cabin and good sound proofing, was soon eclipsed by the arrival of turboprop-powered aircraft such as the Vickers Viscount and, some years later, the Lockheed Electra, which featured more reliable engines and faster speeds. The coming of turboprops and the dawning of the jet age caused the Ambassador to fall out of favour, along with negative publicity arising from two fatal crashes.

Variants

 * AS.57 Ambassador 1
 * Prototype aircraft with Bristol Centaurus engines, two built.


 * AS.57 Ambassador 2
 * Production aircraft, 21 built.

Projects

 * AS.59 Ambassador II
 * Project for either a twin-engined variant with Bristol Proteus or Bristol Theseus engines or a four-engine variant with Napier Naiads or Rolls-Royce Dart]]s. From the first prototypes, the Ambassador's wing had been stressed for four engine points, but no four-engined variant flew.


 * AS.60 Ayrshire C.1
 * Proposed variant to meet Air Ministry Specification C.13/45 for a medium range military transport. Ten were ordered in October 1946 but were not built, after a review of the design's projected performance produced figures lower than the Air Ministry's requirements.


 * AS.64
 * Proposed military transport variant for the Royal Air Force to meet Air Ministry Specification C.26/43, not built.


 * AS.66
 * Proposed civil freighter variant.


 * AS.67
 * Proposed civil freighter variant.

Accidents and incidents
Two Ambassadors made the headlines due to accidents:


 * An Ambassador crashed on take-off from a refuelling stop at Munich on 6 February 1958, while operating a charter flight from Belgrade in Yugoslavia to Manchester, in what became known as the Munich air disaster. This crash received tremendous public attention in the UK as it involved team members and staff of Manchester United football club, together with representatives of the national press.


 * The 3 July 1968 BKS Air Transport Heathrow crash at London Heathrow Airport by a BKS Air Transport Ambassador which killed all but two of its crew as well as several horses which were being transported and their grooms. A parked Trident airliner was damaged beyond repair and another Trident had its tail torn off before the airliner hit terminal buildings and came to rest.  The accident was found to have been caused by the failure of a flap actuating rod in the Ambassador's port (left) wing.  Coincidentally, the Trident which suffered the damaged tail (G-ARPI) was subsequently repaired and later involved in an (unconnected) fatal accident in June 1972.

Other accidents and incidents:


 * 8 April 1955: G-AMAB, Sir Francis Bacon of British European Airways was damaged beyond repair in a forced landing south-west of Düsseldorf, Germany.
 * 16 April 1966: G-ALZZ of Dan-Air was damaged beyond repair when landing at Beauvais, France.
 * 30 September 1968: G-AMAG of Dan-air was damaged beyond repair in a wheel up landing at Manston, Kent, United Kingdom.

Civil Operators

 * Australia
 * Butler Air Transport
 * Norway
 * Norrønafly
 * New Zealand
 * South Seas Airways
 * Switzerland
 * Globe Air
 * United Kingdom
 * Autair International Airways
 * BKS Air Transport
 * British European Airways.
 * Dan Air
 * Decca Navigator Company
 * Rolls-Royce
 * Shell Aviation Limited

Military operators

 * Jordan
 * Royal Jordanian Air Force.
 * Morocco
 * Moroccan Royal Flight

Aircraft on display
One Elizabethan, Christopher Marlowe (G-ALZO, c/n 5226), survives and is under long term major restoration by the Duxford Aviation Society at the Imperial War Museum Duxford near Cambridge.