HP.81 Hermes | |
---|---|
General information | |
Type | Airliner |
Manufacturer | Handley Page |
Primary user | BOAC |
Number built | 29 |
History | |
Manufactured | 1945–1951 |
Introduction date | 6 August 1950 |
First flight | 2 December 1945 |
Retired | 1965 |
Developed from | Handley Page Hastings |
The Handley Page HP.81 Hermes was a civilian airliner designed and produced by the British aircraft manufacturer Handley Page.
The Hermes was developed during the 1940s in parallel with the closely related Handley Page Hastings military transport. It was a low-wing monoplane, with most examples being powered by four piston engines. Originally intended to enter service in advance of the Hastings, development of the Hermes was delayed by the fatal loss of the first prototype during its maiden flight on 2 December 1945. Measures were taken to improve the airliner's stability as well as to expand its capacity, which sufficiently impressed the British Overseas Airways Corporation (BOAC) into placing a sizeable order for 25 HP 81 Hermes IV on 4 February 1947. A pair of turboprop-powered development aircraft were also ordered by the Ministry of Supply for experimental flights.
The Hermes entered airline service on 6 August 1950, having been delayed by roughly one year due to initial production aircraft being overweight. They would be operated by BOAC, the most prominent operator of the type, for less than a decade before they were sold onto other operators largely due to the rapid advances in airliners made during this era. During its later years of service, second hand Hermes were routinely used by various charter airlines. The final Hermes flight was performed sometime during 1969, by which point most of the type had already been scrapped as obsolete. A single example has been partially preserved.
The Hermes can be traced back to discussions held by the Air Staff (United Kingdom) as early as summer 1943. [1] At the time, authorities were considering not only the need for an immediate successor to the Royal Air Force's (RAF) fleet of Handley Page Halifax in the transport/freighter capacity, but also the role of an interim civil airliner for the post-war years. Accordingly, during December 1944, priority orders were placed for various projects, including both the military and civil programmes proposed by the British aircraft manufacturer Handley Page. [1] For the civil airliner, Specification 15/43 was issued by the Air Ministry; this called for a pressurised civil transport that was capable of carrying up to 34 first class or 50 tourist class passengers. [1]
During April 1944, at the urging of George Volkert, Handley Page's chief designer, to settle production priorities, the company's founder and managing director Frederick Handley Page decided to merge the work of several projects and prioritise the transport aircraft; this also aligned with the release of Specification C.3/44, which sought a multipurpose transport. [2] Handley Page's proposal was accepted with no meaningful alterations sought. Shortly thereafter, it was recognised that development of the civil transport posed less of a challenge than the military transport project, thus it was decided that the airliner programme would be flown first. [3] The military transport aircraft, which would share a relatively high level of similarities with the civil project, would enter service as the Handley Page Hastings, while the civil transport became known as the Hermes. [4] [5]
Despite the intentional similarities, there were distinct design differences between the two aircraft. Unlike the tailwheel of the Hastings, the Hermes was planned to have a nosewheel landing gear, although the first two prototypes were completed with a tailwheel undercarriage. [5] Despite the differences, both aircraft remained similar enough that they were produced using the same primary assembly jigs. The first prototype was effectively an unpressurised "bare shell", while the second featured a pressurised cabin and was fully equipped in most respects. [5] On 9 November 1945, a mock-up conference was held at the company's Cricklewood facility, attended by various airline officials and industry figures. Rapid progress on the first prototype's construction enabled it to commence ground trials at Radlett on 1 December 1945. [6]
While Handley Page had intended for the Hermes to be introduced in advance of the Hastings from an early stage of development, a delay to its production was necessitated after the first prototype (HP 68 Hermes 1), registered G-AGSS, crashed during its maiden flight shortly after takeoff on 2 December 1945. [6] It is believed that the aircraft had encountered severe longitudinal instability due to elevator overbalance. Handley Page's chief test pilot and the chief test observer were both killed in the incident, while the prototype was completely destroyed by a post-impact fire. [7]
In order to sufficiently resolve the instability that caused the fatal crash, development of the civil Hermes was protracted, while work on the Hastings progressed more smoothly. [8] This delay presented the opportunity to undertake design revisions and improvements; it was decided that the second prototype's length would be extended to produce the HP 74 Hermes II. The prospects of powering the type with turboprop engines was also investigated around this time, but ultimately decided against. [9] The first Hermes II (G-AGUB) performed its first flight on 2 September 1947; it quickly proved to not only have greater stability, but to also possess a superior lift coefficient to the Hastings as well. On 4 September 1948, the type received its certificate of airworthiness, clearing it for service. [4] [10]
On 4 February 1947, firm orders were placed by the British Overseas Airways Corporation (BOAC) for 25 of the definitive HP 81 Hermes IV. This model was furnished with a tricycle undercarriage and powered by four Bristol Hercules radial engines, each capable of generating up to 2,100 hp (1,570 kW). [11] Additionally, a pair of Hermes V airliners were also ordered, the primary difference of this model was the use of four Bristol Theseus turboprop engines instead. Further turboprop-powered developments of the Hermes were also proposed to potential customers as a competitor to types such as the Bristol Britannia. [11]
Despite the first Hermes IV (registered G-AKFP) performing its first flight relatively quickly on 5 September 1948, [4] and quantity production being promptly established, BOAC was somewhat unsatisfied by the airliner, primarily due to the early aircraft being overweight. [12] This was in part due to the use of Hastings components and ad-hoc modifications to accelerate flight trials; it was promptly agreed that weight-saving modifications were to be made prior to BOAC issuing its final acceptance of the Hermes. Design alterations to reduce weight included the adoption of lighter floor members. [13]
On 6 August 1950, the Hermes IV finally entered service with BOAC, taking over from the Avro York on the West Africa service from London Heathrow to Accra via Tripoli, Kano and Lagos, with services to Kenya and South Africa commencing before the end of the year. [14] [15] The Hermes IV was used by BOAC on routes to West and South Africa. They were quickly replaced, however by the reliable Canadair Argonaut in 1952, although some re-entered service in July 1954 following the grounding of the de Havilland Comet, being retired again in December. [16] [17]
This was not the end of the Hermes in airline service, however, as surplus aircraft were sold to independent charter airlines, with Airwork purchasing four in 1952, others being operated by Britavia and Skyways, particularly in the trooping role. [18] Many of these aircraft were fitted with Hercules 773 engines, which could be operated on lower octane fuel than the original Hercules 763s, being designated as Hermes IVA. They returned to Hermes IV standards when fuel supplies improved. [18] [19]
Later, the Hermes were flown on inclusive tour holiday flights from the UK. The last operational civil Hermes, G-ALDA, flown by Air Links Limited, was retired on 13 December 1964, and was scrapped nine days later. [20] [21]
The two turboprop Hermes V were owned by the Ministry of Supply and made their first flights in August 1949. [22] They were used for development of the Bristol Theseus turboprop engine. The first aircraft was lost in a wheels-up landing at Chilbolton airfield on 10 April 1951, but the second continued development flying with the Aeroplane and Armament Experimental Establishment (A&AEE) at MOD Boscombe Down and the Royal Aircraft Establishment (RAE) at Farnborough Airport until its retirement during September 1953. [23]
The prototype Hermes II was given military markings in October 1953 as VX234 and was used for various research and development programmes, including the testing of airborne radar for the Royal Radar Establishment at RAF Defford, Worcestershire. It was finally retired in 1969, at which point the aircraft had been the final Hermes in operation. [24]
The fuselage of a Hermes IV (the former BOAC aircraft G-ALDG named Horsa) is preserved at the Imperial War Museum Duxford. [25]
All 29 aircraft were built at Radlett Aerodrome, Hertfordshire, England.
Data fromJane's All the World's Aircraft 1950-51 [36]
General characteristics
Performance
Related development
Aircraft of comparable role, configuration, and era
Handley Page Limited was a British aerospace manufacturer. Founded by Frederick Handley Page in 1909, it was the United Kingdom's first publicly traded aircraft manufacturing company. It went into voluntary liquidation and ceased to exist in 1970. The company, based at Radlett Aerodrome in Hertfordshire, was noted for its pioneering role in aviation history and for producing heavy bombers and large airliners.
The Airspeed AS.57 Ambassador is a British twin 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 Bristol Type 167 Brabazon was a large British piston-engined propeller-driven airliner designed by the Bristol Aeroplane Company to fly transatlantic routes between the UK and the United States. The type was named Brabazon after the Brabazon Committee and its chairman, Lord Brabazon of Tara, which had developed the specification to which the airliner was designed.
The Bristol Type 175 Britannia is a retired British medium-to-long-range airliner built by the Bristol Aeroplane Company in 1952 to meet British civilian aviation needs. During development two prototypes were lost and the turboprop engines proved susceptible to inlet icing, which delayed entry into service while solutions were sought.
The Avro York was a British transport aircraft developed by Avro during the Second World War. The design was derived from the Avro Lancaster heavy bomber, several sections of the York and Lancaster being identical. Due to the importance of Lancaster production, York output proceeded slowly until 1944, after which a higher priority was placed upon transport aircraft.
The Handley Page HP.67 Hastings is a retired British troop-carrier and freight transport aircraft designed and manufactured by aviation company Handley Page for the Royal Air Force (RAF). Upon its introduction to service during September 1948, the Hastings was the largest transport plane ever designed for the service.
The Handley Page HP.137 Jetstream is a small twin-turboprop airliner, with a pressurised fuselage. The aircraft was designed to meet the requirements of the United States commuter and regional airline market. The design was later improved and built by British Aerospace as the BAe Jetstream 31 and BAe Jetstream 32, featuring different turboprop engines.
The Vickers VC.1 Viking is a British twin-engine short-range airliner derived from the Vickers Wellington bomber and built by Vickers-Armstrongs Limited at Brooklands near Weybridge in Surrey. After the Second World War, the Viking was an important airliner with British airlines, pending the development of turboprop aircraft like the Viscount. An experimental airframe was fitted with Rolls-Royce Nene turbojets and first flown in 1948 as the world's first pure jet transport aircraft. Military developments were the Vickers Valetta and the Vickers Varsity.
The Handley Page H.P.42 and H.P.45 were four-engine biplane airliners designed and manufactured by British aviation company Handley Page, based in Radlett, Hertfordshire. They held the distinction of being the largest airliners in regular use in the world on the type's introduction in 1931.
The Short S.45 Seaford was a 1940s flying boat, designed as a long range maritime patrol bomber for RAF Coastal Command. It was developed from the Short S.25 Sunderland, and initially ordered as "Sunderland Mark IV".
The Short Solent is a passenger flying boat that was produced by Short Brothers in the late 1940s. It was developed from the Short Seaford, itself a development of the Short Sunderland military flying boat design.
The Handley Page HPR.7 Dart Herald is a British turboprop passenger aircraft, designed in the 1950s as a DC-3 replacement, but only entering service in the 1960s by which time it faced stiff competition from Fokker and Avro. Sales were disappointing, contributing in part to the demise of Handley Page in 1970.
The de Havilland DH.91 Albatross was a four-engined British transport aircraft of the 1930s manufactured by de Havilland Aircraft Company Limited. Seven aircraft were built between 1938 and 1939.
The Avro Type 688 Tudor was a British piston-engined airliner based on Avro's four-engine Lincoln bomber, itself a descendant of the famous Lancaster heavy bomber, and was Britain's first pressurised airliner. Customers saw the aircraft as little more than a pressurised DC-4, and few orders were forthcoming, important customers preferring to buy US aircraft. The tailwheel undercarriage layout was also dated and a disadvantage.
The Handley Page W.8, W.9 and W.10 were British two- and three-engine medium-range biplane airliners designed and built by Handley Page.
The Short S.26 G-class was a large transport flying boat designed and produced by the British aircraft manufacturer Short Brothers. It was designed to achieve a non-stop transatlantic capability, increasing the viability of long distant services/duties.
The Short L.17 Scylla was a British four-engined 39-seat biplane airliner designed and built by Short Brothers at the request of Imperial Airways to supplement the Handley Page H.P.42 fleet already in service after Handley Page quoted an excessive price for two additional H.P.42s. They were ordered in 1933.
The Handley Page (Reading) H.P.R.1 Marathon was a British four-engined civil transport aircraft, capable of seating up to 20 passengers. It was designed by Miles Aircraft Limited and largely manufactured by Handley Page (Reading) Limited at Woodley Aerodrome, Reading, England.
The Bristol Ten-seater and Bristol Brandon were British single-engine biplane transport aircraft built by the Bristol Aeroplane Company in the early 1920s. Only three were built, two of which were used as civil transports and one of which served with the Royal Air Force.
British Aviation Services Limited (Britavia) was an early post-World War II airline holding company and air transport operator that could trace its roots back to 1946. Its main activities included trooping, inclusive tour (IT) and worldwide passenger and freight charter services. British Aviation Services' first investment in a British independent airline occurred in 1946, when it acquired a minority interest in Silver City Airways. Silver City Airways operated the world's first cross-Channel air ferry service on 13 July 1948. It subsequently became British Aviation Services' biggest operating division. In 1953, British Aviation Services took over the independent airline Air Kruise. The same year, BAS Group also took control of Aquila Airways, the last commercial flying boat operator in the United Kingdom. The completion of these acquisitions by mid-1954 resulted in a reorganisation of the British Aviation Services group, with British Aviation Services Ltd (BAS Group) becoming the group's holding company and Britavia one of its operating subsidiaries. By the late 1950s, BAS Group became Britain's largest independent airline operator. Its numerous operating divisions included Britavia's Hermes Division at Blackbushe Airport and Aquila Airways's Flying Boat Division at Hamble near Southampton. The former concentrated on trooping services and inclusive tours while the latter provided scheduled services to Portugal, the Canary Islands and Italy. In 1962, BAS Group merged with British United Airways (BUA), which by that time had replaced BAS as the UK's largest independent airline operator.