Boulton Paul Defiant

Boulton Paul Aircraft · United Kingdom · first flew 1937 · fighter

The Boulton Paul Defiant was a two-seat British turret fighter of World War II, designed around a four-gun hydraulically powered dorsal turret with no fixed forward armament. Its unusual concept achieved early successes before opponents learned to attack from below.

Recognition (WEFT)

W — WingsLow-mounted, tapered
E — Engines1 × piston, nose-mounted
F — Fuselage10.77 m fuselage
T — TailConventional

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Unmistakable among RAF fighters by its large, blunt-nosed dorsal turret immediately aft of the cockpit, giving the fuselage a characteristic humped profile with no guns visible on the wings or nose.

Specifications

Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.

History

First flying in 1937, the Defiant entered service in 1940 and scored notable kills during the Dunkirk evacuation before Luftwaffe pilots discovered its blind spot beneath the nose. After suffering heavy losses in daylight combat, it was transferred to night-fighter duties, where it performed well through 1941–42. It later served in air-sea rescue and target-towing roles.

Variants

The Mk I used a Merlin III; the Mk II introduced the Merlin XX with a two-stage supercharger for improved high-altitude performance. The TT Mk III was the main target-tug variant.

Where you'll see it

Served with the RAF throughout the Battle of Britain and subsequent night-fighter campaigns over Britain; also used by No. 2 Air Observer School and various training units.

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