Naval Air Station at Pensacola.jpg
Curtiss F5L patrol plane at Pensacola Naval Air Station
Role Military flying boat
National origin United Kingdom
Manufacturer Naval Aircraft Factory (137)
Curtiss Aircraft (60)
Canadian Aeroplanes Limited (30)
Designer John Cyril Porte
First flight 15 July 1918[1]
Introduction November 1918
Retired 1928
Primary users United States Navy
Aeromarine Plane and Motor Company (Aeromarine 75)
Number built 227
Developed from Felixstowe F.5
Variants Naval Aircraft Factory PN

The twin-engine F5L was one of the Felixstowe F series of flying boats developed by John Cyril Porte at the Seaplane Experimental Station, Felixstowe, England, during the First World War for production in America.

A civilian version of the aircraft was known as the Aeromarine 75.

Design and development

The first Naval Aircraft Factory F5L, 24 July 1918.[1]
The first Naval Aircraft Factory F5L, 24 July 1918.[1]

Porte had taken the Curtiss H-12, an original design by the American Glenn Curtiss, and developed it into a practical series of flying boats at the Felixstowe station. They then took their F.5 model and further redesigned it with better streamlining, a stronger hull using veneer instead of doped linen and U.S.-built 330 hp (later 400 hp) Liberty 12A engines. The prototype was built and tested in England and the design then taken over by the Naval Aircraft Factory, Philadelphia, where further modifications were made to suit their production methods under wartime conditions.[2] The American-built version was also known as the Curtiss F5L and (in civilian operation) as the Aeromarine 75.

The F5L was built by the Naval Aircraft Factory (137), Curtiss (60) and Canadian Aeroplanes Limited (30). Some were converted for civilian use by the Aeromarine Plane and Motor Company in 1919.

Operational history

The F5L entered U.S. service at the end of the war and was the U.S. Navy's standard patrol aircraft until 1928, when it was replaced by the PN-12. In civil service, named the Aeromarine 75, the Felixstowe F5L could accommodate 10 passengers and was operated by Aeromarine Airways on flights from Key West to Havana, carrying the first U.S. Post Office international air mail on flights from New York City to Atlantic City, and from Cleveland to Detroit.


 United States

Accidents and incidents

Aeromarine 75 Columbus flying over Bimini in the Bahamas in 1921.
Aeromarine 75 Columbus flying over Bimini in the Bahamas in 1921.

On 13 January 1923, the Aeromarine Airways Aeromarine 75 Columbus suffered engine failure during a flight from Key West to Havana and landed in the Florida Strait. Buffeted by 10-to-15-foot (3-to-4.5-metre) waves, its hull began to fill with water. Four passengers died, but the ferry ship H. M. Flagler saved the other three passengers and both crew members.[3]


Both a hull and float from a US Navy F5L are preserved at the National Air and Space Museum (Smithsonian). The hull is only partially skinned with wood to reveal structure. Both artefacts are presently in storage and not available for public display.[4]


Data from Flight 31 July 1919,[2] Smithsonian National Air and Space Museum:Felixstowe[4]

General characteristics



See also

Related development

Aircraft of comparable role, configuration, and era


  1. ^ a b Molson, Kenneth M. (1978). "The Felixstowe F5L". Cross & Cockage Great Britain Journal. 9 (2): 49, 52. Retrieved 7 July 2017.
  2. ^ a b "USA Navy F-5-L Flying Boat". Flight. XI (No.31) (553): 1024–1026. 31 July 1919.
  3. ^ Ranter, Harro. "ASN Aircraft accident Aeromarine 75 registration unknown Havana, Cuba". aviation-safety.net. Retrieved 24 June 2020.
  4. ^ a b "Felixstowe (NAF) F-5-L (hull only)". Smithsonian National Air and Space Museum (Smithsonian). Archived from the original on 1 September 2006. Retrieved 24 June 2020.