Supermarine Channel

Supermarine

Industry	Aviation, Aircraft manufacturing
Headquarters	Southampton , United Kingdom
Products	Aircraft, including the Supermarine Channel flying boat

Supermarine Channel

The Supermarine Channel—initially known as the Supermarine Channel Type—was an adaptation of the AD Flying Boat, acquired by Supermarine from the British Air Ministry and redesigned for civilian use with the goal of establishing scheduled flights over the English Channel. These aircraft received their airworthiness certificates in July 1919. The first model, referred to as Channel I or Mark I, was equipped with a 160 horsepower (120 kW) Beardmore engine. A subsequent variant, named Channel II, featured a more powerful 240 horsepower (180 kW) Armstrong Siddeley Puma engine. Supermarine engineered the aircraft to carry up to four passengers and developed a range of interchangeable cabin layouts that could be quickly swapped, allowing the Channel to serve roles including fighter duties or pilot training.

Operations with the Channel commenced in August 1919, initially transporting passengers across the Solent to the Isle of Wight. In 1920, Norway's first airline, Det Norske Luftfartsreder A/S of Christiania, acquired three units, while four additional Channels were procured by the Norwegian Armed Forces, which began utilizing them from May that year. The New Zealand Flying School also employed a Channel, and Channel II models were dispatched to Bermuda as part of an initiative to advance aviation in that region. Additionally, some were sent to Venezuela to conduct oil exploration surveys in the delta of the Orinoco. In 1921, three Channel II flying boats were obtained by the Imperial Japanese Navy Air Service and transported to Japan aboard the British-led Sempill Mission.

Design and development

File:Supermarine Channel Type layout diagrams.jpg

Supermarine Channel Type layout diagrams

Following the cessation of the commercial flight prohibition in the United Kingdom in May 1919, Supermarine acquired ten AD Flying Boats, which had been stored by the military throughout World War I. These aircraft were intended for initiating scheduled short-distance sea routes across the English Channel. The AD Flying Boat was originally designed in 1915 by British yacht designer Linton Hope.

Once purchased, Supermarine adapted the AD Flying Boats for civilian use and secured their airworthiness certificates by July 1919. The modifications allowed the aircraft to carry up to four passengers, although this capacity was reduced to three when equipped with amphibian landing gear. These updated aircraft were reintroduced under the name Supermarine Channel Type, with the designation 'Channel' first recorded on 2 April 1920. Passenger comfort was a priority; compartments could be enclosed or left open while still offering protection from wind and spray via a windscreen. Additionally, seats were designed to fold upward when not occupied, facilitating cleanliness.

File:Supermarine Channel (1920).jpg

Supermarine Channel (1920)

In October 1920, Flight magazine praised the aircraft for its appeal to maritime enthusiasts, stating it was “the product of men who know and understand the sea and its ways”. The Channel was powered by a 160 horsepower (120 kW) Beardmore 160 hp engine, which was mounted atop an A-frame separate from the wing structure to minimize vibration transmission to the wings. Due to this engine placement, the tail assembly featured a twin-plane configuration. The design also included practical maritime equipment such as an anchor and a boathook. Mitchell’s team engineered a range of interchangeable interiors that could be rapidly swapped, allowing the aircraft to serve in roles ranging from fighter operations to training missions.

The Supermarine Commercial Amphibian, which was Mitchell’s inaugural passenger flying boat design, drew heavily on the Supermarine Channel’s framework. Constructed at Supermarine’s Woolston facility in Southampton, it was developed for an Air Ministry competition held in September 1920.

England

File:Advertisement for Supermarine 4-seater Channel flights.jpg

Advertisement promoting Supermarine four-seater Channel flights (The Aeroplane, August 1919)

Civilian air routes connecting the Port of Southampton with Bournemouth and the Isle of Wight commenced operations in early August 1919. Out of the ten Channels available, five were actively deployed while the remainder were kept on standby, allowing sufficient downtime for maintenance on all aircraft.

The service fulfilled multiple roles: passengers who missed their Isle of Wight ferry could board from Bournemouth Pier for a flight over the Solent, and visitors to the Cowes Regatta had the chance to observe the yachting events from the air aboard a Channel. During the 1919 British railway strike, Channels were utilized to distribute newspapers along the southern coastline. On 28 September 1919, Supermarine initiated the first international flying boat route, temporarily transporting fare-paying travelers between Woolston and Le Havre, substituting the steam packet boats that had ceased operation due to strike action. Flights to the Isle of Wight were suspended by Supermarine during winter months and adverse weather conditions.

Norway

File:Supermarine Channel I (Norwegian Postal Service).jpg

A Supermarine Channel operated by Norwegian carrier Det Norske Luftfartsrederi

In May 1920, Norway's inaugural airline, Det Norske Luftfartsreder A/S of Christiania, acquired three Supermarine Channels. The airline launched a mail and passenger route covering Bergen, Haugesund, and Stavanger in August 1920. Subsequently, the company added three Friedrichshafen floatplanes featuring more powerful engines, which outpaced the Channels. By December 1920, after completing over 200 flights, operations ceased due to insufficient passenger demand and costly airmail services.

Following a June 1919 government request for eight naval seaplanes, Supermarine secured a contract to supply Channels, leading to an order of four aircraft for the Norwegian Armed Forces, which entered service from May 1920 onwards. During their service life, two planes (F-40 and F-44) were upgraded with more potent Puma engines. Observing these enhancements in Norwegian aircraft performance, Supermarine similarly re-engined their own Channels, subsequently designating them as Channel II models.

New Zealand, Bermuda, Venezuela and Japan

In 1921, a Channel I was delivered to the New Zealand firm Walsh Brothers for operation by the New Zealand Flying School. On 4 October 1921, the aircraft, registered as G-NZAI by that time, completed the inaugural flight from Auckland to Wellington. Earlier that year, in July 1921, the Channel conducted the first flight over Fiji during a survey mission. When the New Zealand government assumed control of the Flying School's assets following its closure in 1924, G-NZAI was dismantled.

File:Supermarine Channel prior to being sent to South America (1921).jpg

A Supermarine Channel II at Woolston, Southampton, before shipment to South America (1921)

In 1920, three Channel aircraft were deployed in Bermuda as part of an initiative to advance aviation within the region. Hal Kitchener of the Royal Flying Corps returned to Bermuda and co-founded the Bermuda and West Atlantic Aviation Company in early 1920, aiming to establish Bermuda as a hub for aerial survey operations. The company received several planes including three Avro 504 seaplanes and three Channel I flying boats. Facilities such as hangars and a slipway were constructed on Hinson's Island.

In 1921, the British Controlled Oilfields Company engaged the Bermuda and West Atlantic Aviation Company Limited to perform an aerial survey of the Orinoco delta. After outfitting two Channel II aircraft with specialized camera gear and conducting trials in Britain, these planes were shipped across the Atlantic to carry out the mission. Led by Cochran Patrick, the expedition team comprised two pilots, three mechanics, and four photographers who mapped numerous previously uncharted small streams and mangrove swamps—a task deemed nearly impossible without aviation support.

On 14 March 1921, a demonstration flight of the Channel took place for a Japanese naval delegation that included the chief of the Imperial Japanese Navy Air Service. Despite strong winds during the flight around the Isle of Wight and across the Solent, the aircraft performed impressively. This led to Japan acquiring three Channel II flying boats, which were subsequently transported as part of the British-led Sempill Mission to Japan.

Military users

Template:CHL

• Chilean Air Force – procured a single aircraft.
• Chilean Navy obtained one Channel featuring a modified hull design (resembling the Supermarine Seal II) in 1922.

Template:JPN

• Imperial Japanese Navy acquired three units of the Channel.

Template:NOR

• Royal Norwegian Navy Air Service purchased four Channels powered by Beardmore engines in 1920 and later added an additional ex-civilian aircraft. One remained operational until 1928.

Template:SWE

• Royal Swedish Navy bought one Channel in 1921; this aircraft was destroyed during testing.

External links

• [https://collection.motat.nz/objects?query=external_object_id%3A(%2231578%22%2C%2261162%22%2C%2231529%22%2C%2231544%22%2C%2231555%22%2C%2231722%22%2C%2297918%22%2C%2242461%22%2C%2261233%22%2C%2291670%22%2C%2297282%22%2C%2297899%22%2C%2291669%22%2C%2297255%22%2C%2291677%22%2C%2297274%22)&page=1&direction=asc&sort=&hasImages=false&view=lightbox&searchType=shortlist&facetedResults=true Photographs of the Supermarine Channel I supplied to the New Zealand Flying School in 1921
• Details from 'Military Aviation in Sweden' website regarding the Channel II purchased by the Swedish Navy in 1921