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{{Short description|British twin piston-engined airliner, 1947}}
{{Use dmy dates|date=May 2020}}
{{Use British English|date=March 2018}}
{{Infobox aircraft
|name = AS.57 Ambassador
|image = File:ambassador.arp.750pix.jpg
|caption = Dan-Air Ambassador at [[Bristol Airport]] in 1965
|type = [[Airliner]]
|manufacturer = [[Airspeed Ltd]]
|designer = 
|first_flight = 10 July 1947
|introduction = 1951
|retired = 
|status = Retired
|primary_user = [[British European Airways]]
|more_users = <!--up to three more. please separate with <br/>.-->
|produced = 1947–1953
|number_built = 23<ref name="taylor 110">Taylor 1970, p. 110.</ref>
|unit cost = 
|variants = 
}}

The '''Airspeed AS.57 Ambassador''' is a British twin [[Reciprocating engine|piston-engined]] [[airliner]] that was designed and produced by the British aircraft manufacturer [[Airspeed Ltd.]] It was one of the first [[postwar]] airliners to be produced.

The Ambassador was developed in response to a requirement identified by the [[Brabazon Committee]] for a twin-engined short-to-medium-haul airliner as a replacement for the ubiquitous [[Douglas DC-3]]. Airspeed assembled a dispersed design team at Fairmile Manor, Cobham, Surrey, in 1943, which initially worked on a smaller proposal powered by [[Bristol Hercules]] [[radial engine]]s; this was quickly superseded by a larger-capacity design aimed at better fulfilling the expansion in postwar civil air travel, although several entities doubted Airspeed's projected growth in air travel. Fitted with the new but conventional [[Bristol Centaurus]] [[radial engine]]s, the Ambassador was designed to accommodate four [[Napier Nomad]] [[turbo-compound engine]]s, a then-recent innovation. Its fuselage was compatible with [[Cabin pressurization|pressurisation]], this being an optional feature offered to customers.

On 10 July 1947, the first prototype Ambassador conducted its [[maiden flight]] at Christchurch with chief test pilot George Errington at the controls; a total of three prototypes were built. Early on, [[British European Airways]] (BEA) emerged as a key customer for the type, having placed a £3 million order for 20 aircraft in September 1948. Introducing the Ambassador to service in 1951, BEA often referred to the aircraft as the "Elizabethans", as the aircraft were used for the airline's "Elizabethan Class" passenger service.<!--- ManU player, in 30 for 30 documentary ''[[30 for 30#ep91|George Best: All By Himself]]'', talk about the "crash of the Elizabethan" when referring to the [[Munich air disaster]] ---> However, the type was quickly outperformed by the turboprop-powered [[Vickers Viscount]], with BEA opting to withdraw its Ambassadors in 1958.

Secondhand aircraft were operated by several other airlines, including [[Dan-Air]] and [[Northeast Airlines (UK)|Northeast Airlines]]. Despite being produced in relatively small numbers, the Ambassador was operational for longer than had been anticipated by planners.<ref name="taylor 110"/>

==Development==
===Background===
The origins of the Ambassador can be traced to 1943 and the work of the [[Brabazon Committee]], which sought to define what types of aircraft would be desired by the [[postwar]] civil aviation sector. One of the committee's recommendations was a twin-engined short-to-medium-haul replacement for the [[Douglas DC-3]], known as the ''Type 2''.<ref name=Phipp>Phipp 2007, pp. 75–77.</ref> The British manufacturer [[Airspeed Ltd.]] was interested in this requirement and established a small design team to work on the project from a dispersed office in Fairmile Manor at [[Cobham, Surrey|Cobham]] in Surrey in 1943. This effort was headed by ex-[[de Havilland]] [[aeronautical engineer]] Arthur Hagg, who had joined the company earlier that year.<ref name="taylor 110"/>

Early concepts included an [[Cabin pressurization|unpressurised]] aircraft in the 14.5-[[ton]] gross weight class to be powered by a pair of [[Bristol Hercules]] [[radial engine]]s.<ref>Taylor 1970, pp. 110–111.</ref> Work on the endeavour was taken as far as possible without impacting Airspeed's wartime production activity, as the [[World War II|Second World War]] was still raging.<ref>Taylor 1970, p. 111.</ref> In response to changes in planner's preferences, dictating that the interim aircraft be procured so that airliners such as the in-development Ambassador had more development time, thus the design was revised substantially to expand its capacity. By 1944, it was a considerably larger design than the DC-3, with improved comfort and space.<ref>Taylor 1970, pp. 111–112.</ref>

While Airspeed's management believed that postwar demands would demand greater passenger capacities, several figures, including those within the [[British Overseas Airways Corporation]] (BOAC) and the [[Air Ministry]], were less enthusiastic with their projections.<ref>Taylor 1970, pp. 112–113.</ref> The company also promoted the economics of higher utilisation rates and elevated cruise speeds, whereas conventional wisdom amongst airlines was to avoid increasing speeds to reduce fuel consumption. For the Ambassador, Airspeed opted to pursue a cruising altitude of 20,000&nbsp;ft, relatively high for the era.<ref name="taylor 113"/> A comprehensive mockup was completed by November 1944, largely for promotional purposes, while the projected operating cost figures were released during early 1945.<ref name="taylor 113">Taylor 1970, p. 113.</ref>

Immediately following the end of the conflict, the British [[Ministry of Aircraft Production]] placed an order with the company to produce a pair of [[prototype]]s.<ref name="taylor 114"/> While the first prototype was to be un[[Cabin pressurization|pressurised]] and powered by a pair of [[Bristol Centaurus]] [[radial engine]]s, it was envisioned that the second prototype would feature a reinforced fuselage compatible with pressurisation and a wing that could accommodate four [[Napier Nomad]] [[turbo-compound engine]]s. Several officials, including company chairman [[Alan Samuel Butler]], favored the adoption of the new turbopropeller engines.<ref name="taylor 114">Taylor 1970, p. 114.</ref><ref name=Phipp/> By the end of 1945, work had commenced on building structural test sections and [[jig (tool)|jigs]].<ref name="taylor 113"/>

===Into flight===
On 10 July 1947, the first prototype, [[Aircraft registration|registered]] ''G-AGUA'', conducted the type's [[maiden flight]], flown by chief test pilot George B.S. Errington.<ref name="taylor 114"/> After the generally successful first flight, the prototype underwent a month of alterations, including deleting the spring tab and replacing it with geared [[trim tab|tabs]] fitted to the outer rudders and locking the inner rudder; [[Variable-pitch propeller (aeronautics)|reversible propellers]] were also installed. During September 1947, the prototype made its first public display alongside elements of the second prototype, including its cockpit and control system, at the [[Society of British Aircraft Constructors]] (SBAC) show at [[Radlett]].<ref name="taylor 115">Taylor 1970, p. 115.</ref>

On 22 November 1947, the programme received a setback when the prototype was forced to perform a [[belly landing]] after the port [[landing gear|undercarriage]] leg failed to deploy due to a loss of [[Hydraulics|hydraulic]] pressure.<ref name="taylor 115"/> This did not seemingly deter customer confidence, as the newly created operator [[British European Airways]] (BEA) continued to openly express their preference for the type, and in September they placed a £3 million order for 20 Ambassadors.<ref name=Singfield/><ref name="taylor 119">Taylor 1970, p. 119.</ref> This support was so impactful that, according to aviation author H. A. Taylor, rival aircraft manufacturer [[Vickers]] was close to cancelling development of the [[Vickers Viscount|Viscount]] over fears that airlines held a preference for advanced piston-powered airliners over the unfamiliar turboprop.<ref>Taylor 1970, pp. 115–116.</ref>

During flight testing, it was found that the aircraft possessed particularly favourable low speed characteristics.<ref name="taylor 1167"/> Having been explored in depth beforehand, this was dramatically displayed at the 1948 [[Farnborough Airshow]], becoming the only aircraft in history to perform such an aerial display with one engine out throughout. This was a deliberate choice, with the inactive engine's propeller being [[Feathering (propeller)|feathered]] prior to taking off and remaining so until after landing.<ref name="taylor 117">Taylor 1970, p. 117.</ref> The first prototype performed the majority of flight testing through late 1948.<ref name="taylor 1189">Taylor 1970, pp. 118–119.</ref>

A total of three prototypes were constructed for the test programme.<ref name=Singfield>Singfield 2000, p. 12.</ref> The second Ambassador, ''G-AKRD'',<ref name=Jackson1>Jackson 1973, p. 30.</ref> was the first to feature pressurisation and was equipped with a full passenger cabin configuration for demonstration flights.<ref name="taylor 117"/> This second prototype was subsequently used by the [[Bristol Aeroplane Company]] from 1953 for flight-testing the [[Bristol Proteus]] 705 turbine engine. From March 1958, it was used by [[Rolls-Royce Limited|Rolls-Royce]] for testing the [[Rolls-Royce Dart|Dart]] and [[Rolls-Royce Tyne|Tyne]] turboprops.<ref name=Phipp/><ref name="taylor 118"/> The third prototype and first Ambassador 2 ''G-ALFR'' was initially used for BEA proving trials,<ref name=Jackson1/> and in 1955 it also supported the development trials of the [[Napier Eland]] turbine engine. During 1958, intensive simulated airline flying, to pave the way for BEA Vanguards, was performed using two Tyne-powered Ambassadors.<ref>Gunston 1989, p. 128.</ref><ref>Taylor 1970, pp. 127–128.</ref>

During the latter stage of development, some issues were uncovered.<ref name="taylor 119"/> The wing, which had been designed to induce [[laminar flow]] characteristics, was relatively unconventional in its design; testing revealed that it lacked sufficient strength, and redesigning the wing was not straightforward. Technical assistance was provided by [[de Havilland]] and the issue was proven to be resolved in December 1949.<ref name="taylor 119"/> Three minor accidents during demonstration flights, while causing no serious damage, often delayed testing and did not inspire confidence amongst potential customers.<ref>Taylor 1970, pp. 119–121.</ref> Quantity production of the Ambassador commenced during 1950, leading to the first production standard aircraft, destined for BEA, performing its first flight on 12 January 1951.<ref name="taylor 1212">Taylor 1970, pp. 121–122.</ref>

==Design==
The Airspeed Ambassador was an all-metal twin-engine airliner, designed to serve short-to-medium haul routes.<ref name="taylor 112">Taylor 1970, p. 112.</ref> It was relatively advanced for the era, being relatively aerodynamically clean, having a [[Aspect ratio (aeronautics)|high aspect–ratio wing]] with hoped-for near-[[Laminar flow]] characteristics, a [[Tricycle landing gear|tricycle undercarriage]], a steerable nosewheel, integral fuel tanks, and other recent innovations.<ref name="taylor 1167">Taylor 1970, pp. 116–117.</ref> Distinctive external features of the Ambassador included its three low [[Vertical stabilizer|tailfins]] and a long pointed nose, giving it a resemblance to the larger transcontinental [[Lockheed Constellation]]. Its tricycle gear gave it a more modern appearance than contemporaries such as the [[DC-3]], [[Curtiss Commando]], [[Avro Lancastrian]] and [[Vickers VC.1 Viking|Vickers Viking]]s that were common on Europe's shorter airline routes.

In a standard configuration, the Ambassador could accommodate up to 47 passengers; somewhat unusually, its passenger cabin could be either [[Cabin pressurization|pressurised]] or not as the customer preferred.<ref name="taylor 112"/> To reduce cabin noise levels, considerable effort went into [[Soundproofing|soundproof]]ing and general furnishings; Taylor described the Ambassador as being particularly quiet for a piston engine airliner, although also noting it could not equal the lower noise levels of [[turboprop]]-powered airliners such as the [[Vickers Viscount]].<ref>Taylor 1970, pp. 117–118.</ref> It was typically powered by conventional [[Bristol Centaurus]] [[radial engine]]s, although individual aircraft were reengined with various powerplants, including turboprops.<ref name="taylor 118">Taylor 1970, p. 118.</ref>

To increase cruise performance, designers made great efforts to minimise [[Aerodynamic drag|drag]], using a [[NACA]] laminar-flow wing section. The predicted low-drag performance was not completely realized, however, due to structural features for wing construction, propeller slipstream over the inner wing, and increased skin roughness in actual service conditions. The engine [[nacelle]]s were initially designed with inwardly-opening [[Louver|louvres]] for exhaust gases and cooling air rather than the usual outwardly opening "gills". However, these proved inadequate for cooling the engine, thus the gills were reinstated. Engine-out climb performance was enhanced by being able to [[Propeller (aeronautics)#Feathering|feather]] the propeller using a zero-torque signal from the engine.<ref>Boot 1990, pp. 25–26.</ref>

==Operational history==
During 1952, [[British European Airways]] (BEA) introduced the first of its 20 strong fleet of Ambassadors to revenue service, the airline referred to them as the "Elizabethan Class" in honour of the newly crowned [[Queen Elizabeth II]].<ref name=Singfield/> The planned 1951 introduction date had been pushed to 1952 to address development issues.<ref name="taylor 119"/> By May 1951, intense proving trials of the Ambassador were being conducted by a joint team of Airspeed and BEA employees, while official BEA training commenced in August of that year.<ref name="taylor 1212"/> The flagship of BEA's fleet was ''G-ALZN'', appropriately named "RMA Elizabethan".<ref>Taylor 1970, p. 122.</ref> The first "Elizabethan" scheduled flight was from [[Heathrow Airport]] to [[Paris–Le Bourget Airport|Paris Le Bourget]] on 13 March 1952, soon the type was used across BEA's main [[United Kingdom|UK]] routes.<ref name="taylor 125">Taylor 1970, p. 125.</ref>

According to Taylor, the Ambassador's performance gave BEA a competitive edge over its rivals.<ref name="taylor 125"/> By December 1955, the "Elizabethan Class" had reached 2,230 flying hours annually, per aircraft, the highest in BEA's fleet. However, the rival [[Vickers Viscount]], which was introduced in 1953, was even more popular with BEA's passengers than the Ambassador.<ref name="taylor 125"/> Rival airlines, such as [[Air France]], had also quickly introduced the Viscount, and thus held an advantage over BEA's Elizabethan service. Accordingly, the airline decided to withdraw the type despite its relative youth, with BEA's final scheduled Ambassador flight on 30 July 1958.<ref name="taylor 125"/>

There were no further sales of the Ambassador. Aviation authors [[Bill Gunston]] and [[Peter Masefield]] laid this lack of success largely upon attitudes within [[de Havilland]]'s management following its takeover of Airspeed in 1951; they allegedly preferred to use Airspeed's factory at [[Christchurch Airfield]] to produce military jets designed by de Havilland.<ref>Masefield and Gunston 2002, p. 83.</ref> One example of de Havilland's undermining of potential sales was the recall of the Sales Director to de Havilland's headquarters at [[Hatfield Aerodrome]] ([[Hertfordshire]], England) from Australia, despite his reportedly being near to finalizing an order from [[Trans-Australia Airlines]] for 12 Ambassadors.<ref>Masefield and Gunston 2002, p. 214.</ref> Taylor observed that prospective customers were often sceptical that Airspeed, being a relatively small company, could be relied upon for technical support and components.<ref>Taylor 1970, p. 126.</ref>

[[File:Airspeed Eland Ambassador at Farnborough 1955.jpg|thumb|right|Napier's Eland engine test-bed Ambassador ''G-ALFR'' at Farnborough SBAC Show 1955]]
Following the type's disposal by BEA, secondhand Ambassadors helped to establish the scheduled and charter flight operations of [[Dan-Air]], an important airline in the development of the [[package holiday]]. The type was also used in the UK by [[Court Line|Autair]] and [[BKS Air Transport]]. Secondhand Ambassadors were also flown for short periods by other airlines including Butler Air Transport (Australia), Globe Air (Switzerland) and [[Norrønafly]] (Norway).<ref>Jackson 1973, pp. 395–396.</ref><ref>Taylor 1970, pp. 129–130.</ref> Multiple entities, such as [[Royal Dutch Shell]] and the [[Royal Jordanian Air Force]], also procured Ambassadors for private purposes.<ref>Taylor 1970, p. 127.</ref>
[[File:Passagiere boarden ein Flugzeug G-AMAH Airspeed Ambassador der British European Airways 1954..jpg|alt=Passengers board a British European Airways G-AMAH Airspeed Ambassador aircraft in 1954.|thumb|Passengers board a British European Airways G-AMAH Airspeed Ambassador aircraft in 1954.]]
The initial popularity of the Ambassador, with its pressurised cabin and good [[soundproofing]], was soon eclipsed by the arrival of [[turboprop]]-powered aircraft such as the [[Vickers Viscount]] and, some years later, the [[Lockheed L-188 Electra|Lockheed Electra]], which featured more reliable engines and faster speeds.

==Variants==
[[File:Airspeed Ambassador G-AMAD BKS 1965.jpg|thumb|right|[[BKS Air Transport]] Ambassador ''G-AMAD'' in 1965]]
;AS.57 Ambassador 1
:Prototype aircraft with [[Bristol Centaurus]] 130 engines, two built.<ref>Jackson 1973, p. 25.</ref>
;AS.57 Ambassador 2
:Production version with Bristol Centaurus 661 engines, 21 built including the production prototype.<ref>Jackson 1973, p. 26.</ref>

===Projects===
;AS.59 Ambassador II
:Project for either a twin-engined variant with [[Bristol Proteus]] or [[Bristol Theseus]] engines or a four-engined variant with [[Napier Naiad]]s or [[Rolls-Royce Dart]]s.<ref name=Flight1951/> From the first prototypes, the Ambassador's wing had been stressed for four Naiad turboprops, but no four-engined variant flew.<ref>Boot 1990, p. 25.</ref>
;AS.60 Ayrshire C.1
:Proposed variant to meet [[Air Ministry Specification|Air Ministry Specification C.13/45]] for a medium-range military transport with a rear-fuselage loading ramp.<ref name=Flight1951>[http://www.flightglobal.com/pdfarchive/view/1951/1951%20-%200354.htm "Airspeed Type Designations."] ''[[Flight International]],'' 23 February 1951, p. 228.</ref> 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.<ref>Boot 1990, p. 24.</ref>
;AS.64
:Proposed military transport variant for the [[Royal Air Force]] to meet [[Air Ministry Specification|Air Ministry Specification C.26/43]], not built.<ref name=Flight1951/>
;AS.66
:Proposed civil freighter variant.<ref name=Flight1951/>
;AS.67
:Proposed civil freighter variant.<ref name=Flight1951/>

==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.<ref name="piston">Eastwood and Roach 1991, p. 7.</ref><ref>[http://aviation-safety.net/database/record.php?id=19550408-0 "Accident description: Airspeed AS.57 Ambassador 2, 8 April 1955."] ''Aviation-safety.net.'' Retrieved 13 November 2010.</ref><ref name="taylor 125"/> This aircraft had often been used by the Queen and Prince Philip when travelling to Europe in the early 1950s.<ref>Eastwood and Roach 1991, p. 12.</ref>
* 6 February 1958: ''G-ALZU'', ''Lord Burghley'', also of BEA, in what became known as the [[Munich air disaster]], crashed on takeoff after a refuelling stop at [[Munich]] while operating a charter flight from [[Belgrade]], Yugoslavia, to [[Manchester]], England. This crash received tremendous public attention in the UK as it involved team members and staff of [[Manchester United F.C.|Manchester United Football Club]], together with representatives of the national press. Of the 44 people on the plane, 21 died in the crash and 2 died later, including eight Manchester United players.<ref>[http://aviation-safety.net/database/record.php?id=19580206-0 "Accident description: Airspeed AS.57 Ambassador 2, 6 February 1958."] ''Aviation-safety.net.'' Retrieved 6 May 2012.</ref> The investigation eventually focused on runway slush adversely affecting the speed of the plane as it attempted to take off.
* 14 April 1966: ''G-ALZX'' of [[Dan-Air]] was damaged beyond repair when its undercarriage collapsed on landing at [[Beauvais]], France.<ref>{{Cite web|url=https://aviation-safety.net/database/record.php?id=19660414-1|title=ASN Aircraft accident Airspeed AS.57 Ambassador 2 G-ALZX Beauvais-Tillé Airport (BVA)|first=Harro|last=Ranter|website=aviation-safety.net}}</ref>
* 14 September 1967 ''G-ALZS'' of [[Autair]] was damaged beyond repair on landing at [[Luton Airport]], UK. The aircraft overran the runway and ended up in soft clay.<ref>{{Cite web|url=https://aviation-safety.net/database/record.php?id=19670914-0|title=ASN Aircraft accident Airspeed AS.57 Ambassador 2 G-ALZS London-Luton Airport (LTN)|first=Harro|last=Ranter|website=aviation-safety.net}}</ref>
* 3 July 1968: ''G-AMAD'' of [[Northeast Airlines (UK)|BKS Air Transport]] [[1968 Heathrow BKS Air Transport Airspeed Ambassador crash|crashed]] at [[London Heathrow Airport]]. All but two of its crew as well as several horses which were being transported and their grooms, were killed. A parked [[Hawker Siddeley Trident|Trident]] airliner was damaged beyond repair (''G-ARPT'') and another Trident had its tail torn off before the airliner hit terminal buildings and came to rest. The accident was caused by a failed [[Flap (aircraft)|flap]] actuating rod in the left wing. The Trident which suffered the damaged tail (''G-ARPI'') was subsequently repaired and later involved in an unconnected [[British European Airways Flight 548|fatal accident]] in June 1972.<ref>[http://aviation-safety.net/database/record.php?id=19680703-0 "Accident description: Airspeed AS.57 Ambassador 2, 3 July 1968."] ''Aviation-safety.net.'' Retrieved 6 May 2012.</ref>
* 30 September 1968: ''G-AMAG'' of Dan-Air was damaged beyond repair in a [[wheels-up landing]] at [[Manston Airport|Manston]], United Kingdom.<ref name="piston"/><ref>[http://aviation-safety.net/database/record.php?id=19680930-0 "Accident description: Airspeed AS.57 Ambassador 2, 30 September 1968."]''Aviation-safety.net.'' Retrieved 13 November 2010.</ref>

==Operators==

===Civil operators===
;{{AUS}}
*[[Butler Air Transport]] – operated three units.<ref name="BAptp">{{cite web|url=http://britishaviation-ptp.com/airspeed_as57.html|title=Airspeed AS.57 Ambassador|access-date=8 May 2020|publisher=British aviation projects to productions}}</ref>
;{{NOR}}
*Norrønafly – proposed to operate two aircraft but they never entered service.
;{{NZL}}
*South Seas Airways – bought one aircraft but failed to gain an operators licence; the aircraft was not delivered to New Zealand.
;{{SUI}}
*Globe Air – operated three aircraft.<ref name="BAptp"/>
;{{UK}}
[[File:BEA Ambassador at Manchester Ringway.jpg|thumb|right|BEA "Elizabethan" ''G-AMAG'' "Sir Thomas Gresham" at Manchester (Ringway) Airport on the schedule to Heathrow in July 1953]]
*[[Court Line|Autair International Airways]] – operated three aircraft.
*[[BKS Air Transport]] – operated three aircraft.<ref name="BAptp"/>
*[[British European Airways]] – operated twenty aircraft.
*[[Dan-Air]] – operated seven aircraft.
*Decca Navigator Company – one aircraft.
*[[D. Napier & Son|Napier]]
*Rolls-Royce
*Shell Aviation Limited – two aircraft.<ref name="BAptp"/>

===Military operators===
;{{JOR}}
* [[Royal Jordanian Air Force]] operated three former British European Airways aircraft, first one delivered in 1959.<ref name="BAptp"/>
;{{MAR}}
* Moroccan Royal Flight

==Aircraft on display==
[[File:Airspeed Ambassador 2 'G-ALZO' (24379228403).jpg|thumb|right|''G-ALZO'', at the Imperial War Museum Duxford, 2015]]
One Elizabethan, ''[[Christopher Marlowe]]'' (''G-ALZO'', c/n 5226) is on display at the [[Imperial War Museum Duxford|Imperial War Museum]], [[Duxford]] near [[Cambridge]] having undergone major restoration by the Duxford Aviation Society. The restoration was completed in April 2013 and the aircraft is presently part of the Duxford Collection.<ref>{{cite web|title=Airspeed Ambassador 2|url=http://www.britairliners.org/airliner-detail?type=airspeed-ambassador-2&id=36|website=Duxford Aviation Society|access-date=30 December 2020}}</ref>

==Specifications==
[[File:Airspeed Ambassador 3-view silhouette.jpg|thumb|right|Airspeed Ambassador]]
{{Aircraft specs
|ref= ''Airspeed aircraft since 1931'',<ref>Taylor 1970, pp. 132–134.</ref> ''British Civil Aircraft since 1919 Volume 1''<ref>{{harvnb|Jackson|1987|p=29}}</ref>
|prime units?=imp
<!--
        General characteristics
-->
|crew= 3
|capacity= Up to 60 passengers
|length ft= 81
|length in=
|length note=
|span ft= 115
|span in=
|span note=
|height ft= 18
|height in= 4
|height note=
|wing area sqft= 1,200
|wing area note=
|aspect ratio= 11:1
|airfoil='''root:''' [[NACA airfoil|NACA]]; '''tip:''' [[NACA airfoil|NACA]]<ref>{{cite web|last1=Lednicer|first1=David|title=The Incomplete Guide to Airfoil Usage|url=https://m-selig.ae.illinois.edu/ads/aircraft.html|website=m-selig.ae.illinois.edu|accessdate=16 April 2019}}</ref>
|empty weight lb= 35,884
|empty weight note=
|gross weight lb=
|gross weight note=<br/>
*'''Maximum landing weight:''' {{cvt|50000|lb}}
|max takeoff weight lb= 52,000
|max takeoff weight note=
|fuel capacity= {{cvt|1000|impgal|USgal l}} in two integral wing tanks, with provision for {{cvt|600|impgal|USgal l}} in two centre-section bag tanks
|more general=
<!--
        Powerplant
-->
|eng1 number= 2
|eng1 name= [[Bristol Centaurus 661]]
|eng1 type= 18-cylinder air-cooled sleeve-valve piston engines
|eng1 hp= 2,625

|prop blade number=<!-- propeller aircraft -->
|prop name=
|prop dia ft=<!-- propeller aircraft -->
|prop dia in=<!-- propeller aircraft -->
|prop dia note=
<!--
        Performance
-->
|max speed mph= 312
|max speed note= at 75% power with {{cvt|11650|lb}} payload
|cruise speed mph= 300
|cruise speed note= at {{cvt|20000|ft}} at {{cvt|50000|lb}}
:::{{cvt|279|mph|kn km/h}} at 60% power
|stall speed mph=
|stall speed note=
|never exceed speed mph=
|never exceed speed note=
|minimum control speed mph=
|minimum control speed note=
|range miles= 720
|range note= with {{cvt|11650|lb}} payload and no reserves at {{cvt|280|mph|kn km/h}}
:::{{cvt|900|mi|nmi km}} at {{cvt|220|mph|kn km/h}}
:::{{cvt|1560|mi|nmi km}} with {{cvt|7900|lb}} payload max. fuel at {{cvt|280|mph|kn km/h}}
:::{{cvt|1950|mi|nmi km}} with {{cvt|7900|lb}} payload max. fuel at {{cvt|220|mph|kn km/h}}
|combat range miles=
|combat range note=
|ferry range miles=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling ft=
|ceiling note=
|g limits=<!-- aerobatic -->
|roll rate=<!-- aerobatic -->
|glide ratio=<!-- sailplanes -->
|climb rate ftmin= 1,520
|climb rate note= at {{cvt|5000|ft}} at maximum weight
*'''Rate of climb on one engine:''' {{cvt|420|ft/min}} after take-off at maximum weight
:::{{cvt|360|ft/min}} at {{cvt|5000|ft}} at maximum weight
|time to altitude=
|wing loading lb/sqft= 43.3
|wing loading note= at {{cvt|52000|lb}}
|fuel consumption lb/mi=
|power/mass= {{cvt|0.1|hp/lb}} at {{cvt|52000|lb}}
|more performance=<br />
*'''Take-off distance to {{cvt|50|ft}}:''' {{cvt|3270|ft}} at maximum T.O weight
*'''Take-off distance to {{cvt|50|ft}} one engine:''' {{cvt|4950|ft}} at maximum T.O weight
*'''Landing distance from {{cvt|50|ft}}:''' {{cvt|2565|ft}} at max landing weight
|avionics=
}}

==See also==
{{Aircontent
|related=
|similar aircraft=
* [[Convair CV-240 family|Convair CV-240]]
* [[Vickers Viscount]]
|lists=
* [[List of civil aircraft]]
|see also=
}}

==References==
===Citations===
{{Reflist}}

===Bibliography===
* {{cite book|last=Boot|first=Roy|title=From Spitfire to Eurofighter: 45 years of Combat Aircraft Design|location=Shrewsbury, UK|publisher=AirLife Publishing|year=1990|isbn=1-85310-093-5}}
* {{cite book|last1=Eastwood|first1=Tony|first2=John|last2=Roach|title=Piston Engine Airliner Production List|location=West Drayton, UK|publisher=The Aviation Hobby Shop|year=1991|isbn=0-907178-37-5}}.
* Gunston, Bill. ''Rolls-Royce Aero Engines.'' Patrick Stephens Limited, 1989. {{ISBN|1-85260-037-3}}.
* {{cite book|last=Jackson|first=A.J|title=British Civil Aircraft since 1919 Volume 1|location=London|publisher=Putnam|orig-year=1973|year=1987|isbn=0-85177-808-9}}.
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* {{cite book|last1=Masefield|first1=Sir Peter|last2=Gunston|first2=Bill|title=Flight Path|location=Shrewsbury, England|publisher=Airlife|year=2002|isbn=978-1-8403-7283-0}}
* {{cite book|last=Phipp|first=M|title=The Brabazon Committee And British Airliners 1945–1960|location=Stroud|publisher=Tempus|year=2007|isbn=978-0-7524-4374-4}}
*{{cite magazine|last=Quinlan|first=H. G.|title=Talkback|magazine=[[Air Enthusiast]]|date=1984|issue=25 |pages=78–79|issn=0143-5450}} 
* {{cite book|last=Singfield|first=Tom|title=Classic Airliners|location=Leicester, UK|publisher=Midland Publishing|year=2000|isbn=1-85780-098-2}}.
* {{cite book|last=Taylor, H A|title=Airspeed Aircraft since 1931|location=London|publisher=Putnam|year=1970|isbn=0370001109}}

==External links==
{{commons category}}
* [https://web.archive.org/web/20110705022415/http://www.theaviationindex.com/aircraft-types/airspeed-57-ambassador List of magazine articles and publications on the Ambassador]
* [https://web.archive.org/web/20050207185852/http://website.lineone.net/~biggles200/G-alzt.jpg Image of an Ambassador]
* [http://www.flightglobal.com/pdfarchive/view/1947/1947%20-%200515.html "Airspeed (AS.57) Ambassador"] a 1947 ''Flight'' article

{{Airspeed aircraft}}

[[Category:Airspeed aircraft|Ambassador]]
[[Category:1940s British airliners]]
[[Category:Aircraft first flown in 1947]]
[[Category:High-wing aircraft]]
[[Category:Twin piston-engined tractor aircraft]]
[[Category:Triple-tail aircraft]]
[[Category:Aircraft with retractable tricycle landing gear]]