AP 118 · No. 10 Section II · Aircraft Plate 42 / 253

Plate 42 of 253 · Great War · Patrol flying boat

Felixstowe F.5

F.5, N4637, painted as N4637, a Felixstowe F.5 built by the Gosport Aircraft Company and flown by the RAF's seaplane training units and No. 480 Flight at Calshot until it was written off in April 1923: John Porte's twin-engined patrol flying boat, a three-bay biplane of 103 ft 8 in span with long upper-wing extensions braced by kingposts and stabilizer panels, two Rolls-Royce Eagle VIII engines in open mountings between the wings driving four-bladed wooden propellers, a wooden two-step planing hull with an open bow gunner's position and side-by-side cockpit, wing-tip floats under the lower wing, and a tall fin and rudder above a strut-braced tailplane, shown resting level on its keel as if afloat, in the scheme the Gosport Aircraft Company's photograph of N4637 shows: a dark varnished wooden hull and floats, PC10 olive-brown upper surfaces, fin and stabilizers over clear-doped linen undersides, a roundel with 'N4637' aft of it and a large white '7' ahead of it on the hull sides, roundels under the lower wing and blue, white and red stripes on the rudder with the serial in black (shape from the F.5 rigging-notes general arrangement and the original Felixstowe hull drawings; the roundels above the upper wing are standard practice, not seen in a photograph); no complete F.5 survives, and the Norfolk & Suffolk Aviation Museum displays a restored F.5 bow section.

3D model

Turn it over

A procedural model built in Blender from published dimensions, drawings and photographs, painted as N4637, a Felixstowe F.5 built by the Gosport Aircraft Company and flown by the RAF's seaplane training units and No. 480 Flight at Calshot until it was written off in April 1923: John Porte's twin-engined patrol flying boat, a three-bay biplane of 103 ft 8 in span with long upper-wing extensions braced by kingposts and stabilizer panels, two Rolls-Royce Eagle VIII engines in open mountings between the wings driving four-bladed wooden propellers, a wooden two-step planing hull with an open bow gunner's position and side-by-side cockpit, wing-tip floats under the lower wing, and a tall fin and rudder above a strut-braced tailplane, shown resting level on its keel as if afloat, in the scheme the Gosport Aircraft Company's photograph of N4637 shows: a dark varnished wooden hull and floats, PC10 olive-brown upper surfaces, fin and stabilizers over clear-doped linen undersides, a roundel with 'N4637' aft of it and a large white '7' ahead of it on the hull sides, roundels under the lower wing and blue, white and red stripes on the rudder with the serial in black (shape from the F.5 rigging-notes general arrangement and the original Felixstowe hull drawings; the roundels above the upper wing are standard practice, not seen in a photograph); no complete F.5 survives, and the Norfolk & Suffolk Aviation Museum displays a restored F.5 bow section. Drag to orbit, scroll or pinch to zoom · download .glb (888 KB)

Data plate

Specification

First flight, number built and top speed are for the whole family (F.5); engine, crew and dimensions are for the F.5, N4637 modelled here.

History

The F.5

John Porte, a naval officer who had worked with Glenn Curtiss in 1914 on a flying boat meant to cross the Atlantic, took command of the RNAS station at Felixstowe and set about curing the faults of the Curtiss boats the Admiralty had bought. Their hulls were weak and ploughed through the water, so Porte designed new ones with a deeper planing bottom and two steps. The F.2A, a Curtiss H-12 wing and tail on a Porte hull, flew long patrols over the North Sea in 1917 and 1918, hunting U-boats and Zeppelins, and the larger F.3 followed it.

The F.5 was Porte’s attempt to combine the handling of the F.2A with the range and load of the F.3. The prototype, N90, was built at Felixstowe and first flew in November 1917, with a new wing of greater span and a deeper hull. For production the design was changed to use many F.3 components, which made it easier to build but left it little better than the F.3. Short Brothers, Phoenix Dynamo, Gosport Aircraft and S.E. Saunders built 163 in Britain, few of them in time for the war. In the United States the Naval Aircraft Factory and Curtiss built more than 200 F-5Ls with Liberty engines, and Japan built its own version.

After the Armistice the F.5 became the RAF’s standard flying boat. It equipped the flying-boat units at Felixstowe, Calshot and Malta and the seaplane training squadron at Calshot, carrying four Lewis guns and up to 920 lb of bombs, with an endurance of about seven hours. The wooden hulls soaked up water and needed constant care, and from 1925 the F.5 was replaced by the Supermarine Southampton.

This airframe

F.5 N4637 of the RAF seaplane units at Calshot

N4637The airframe modelled

N4637 was built by the Gosport Aircraft Company at Gosport, and the company’s official photograph shows it broadside on its beaching trolley. It served with the RAF’s Seaplane Training Squadron at Calshot and was damaged off Alderney on 6 October 1921, and it was written off with No. 480 (Coastal Reconnaissance) Flight at Calshot on 25 April 1923. No complete F.5 survives. The Norfolk & Suffolk Aviation Museum at Flixton displays a restored F.5 bow section, rescued from use as a garden shed, whose serial is not recorded. The model shows N4637 as the Gosport photograph records it, resting level on its keel as if afloat: a dark varnished wooden hull and floats, PC10 olive-brown upper surfaces, fin and stabilizer panels over clear-doped linen undersides, a roundel on the hull sides with ‘N4637’ aft of it and a large white ‘7’ ahead of it, roundels under the lower wing, and blue, white and red rudder stripes carrying the serial in black. The photograph is on orthochromatic film, so the varnished hull is a reading of its dark tone, and the roundels above the upper wing follow standard practice rather than a photograph. The shape follows the F.5 rigging-notes general arrangement and the original Felixstowe hull drawings.

Where to see one

In the gazetteer

The gazetteer records the F.5 in one UK collection.

Every airframe and serial All 253 plates

Profiles and models are procedural interpretations built in Blender from published dimensions, three-view drawings and photographs of each airframe. Treat the museum aircraft as the reference.