The original wing structure of Supermarine Type 300 Spitfire Mk. I, later referred to as the Type A wing.
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[Crown Copyright]

No discussion about the various Spitfire marks can be complete without referring to the different wing types. An overview of the basic wing types of the Spitfire and the differences between them.

The Merlin-powered Spitfires used four different wing types, A through to D which had the same dimensions and plan but different internal arrangements of armament and fuel tanks. After introducing the Griffon, Supermarine recognized the need for a completely revised laminar-flow wing to facilitate even higher speeds made possible by this powerful engine. Starting with production Spitfire Mk 21, this wing became standard for post-war variants of this famous fighter.

The majority of the day fighter Spitfires from the Mk I through Mk XVIII used four basic wing types, A, B, C and E.

A type

The original wing design, the basic structure of which was unchanged until the arrival of C type wing in 1942. The only armament able to be carried was eight .303-calibre Browning machine guns with 300 rounds per gun.

The one major alteration made to this wing soon after production started was the incorporation of heating for the gun bays to prevent the guns from freezing at altitude. Open structures around the gun bays were blocked off and ducting, drawing hot air from the back of the radiators, was added to the wings. The heated air was exhausted through underwing vents, covered by streamlined triangular blisters, just inboard of the wingtips.

Towards the end of 1940 the fabric covered ailerons were replaced by ones covered in light-alloy.

General arrangement of the Type A wing
[Crown Copyright]

B type

This was the A type wing modified to carry a 20mm Hispano cannon. One type of armament could be fitted, comprising two 20 mm-calibre Hispano Mk II cannon, fed from drum magazines with the capacity of 60 rounds/gun, and four .303 Browning machine guns with 350 rounds per gun.

The retractable underwing landing lamp was repositioned and the innermost machine gun bays were replaced with a single cannon bay, plus a compartment for the drum magazine outboard of the wheel well.

The upper and lower wing skins incorporated blisters to clear the ammunition drum. Under the wings there were two possible blister shapes.

The alloy covered ailerons were standardised on this wing type.

General arrangement of the Type B wing
[Martin Waligorski]

Internal structure of the Type B wing of the Spitfire Mk. Vb.
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[Crown Copyright]