Concise Guide To
Spitfire Wing Types
Part 1
The original wing structure of Supermarine Type 300
Spitfire Mk. I, later referred to as the Type A wing.
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No discussion about the various Spitfire marks can be complete without referring to the different wing types. This article is intended to provide 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.
[Crown Copyright]
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C type
Called "universal wing", this wing was structurally modified to reduce labour and manufacturing time and allow mixed armament options; A or B type armament or a new, yet heavier combination of four 20 mm Hispano cannon.
The undercarriage mountings were redesigned and the undercarriage doors were bowed in cross section allowing the legs to sit lower in the wells, eliminating the upper-wing blisters over the wheel wells and landing gear pivot points.
The revised, strengthened undercarriage legs were raked 2 inches (5.08 cm) further forward, making the Spitfire more stable on the ground and reducing the likelihood of the aircraft tipping onto its nose.
The Hispano Mk II cannon fitted in all cases were now belt-fed from box magazines (the Chattellerault system) allowing to double the ammunition supply to 120 rounds per gun. The fairings over the Hispano barrels were shorter and there was usually a short rubber stub covering the outer cannon port when not in use.
General arrangement of the Type C wing
[Martin Waligorski]
The redesigned upper wing gun bay doors incorporated blisters to clear the cannon belt feed motors. Initially a single wide blister was incorporated that covered both motors. Initial production Spitfires Mk. Vc, such as those which were transported to Malta were factory-fitted with four cannon. In field conditions, it was often sufficient with two cannon armament and many of the four-cannon Spitfires were converted to fly with either outboard or inboard pair of Hispanos, or else converted to B-standard armament. Later on, production aircraft carried the two 20mm Hispanos and four Brownings. In such circumstances, the very large blister on top of the wing was not required and a new, more streamlined cannon breech cover was provided, with narrow blister fairing over the inboard cannon position and flat surface over the second, unused cannon bay.
The inner machine gun bays in C wing were moved outboard to between ribs 13 and 14. Also, the lower surface of the wing no longer had the gun-bay heating vents outboard of the gun bays and the retractable landing lights were no longer fitted.
The wing structure was stressed for provision of hardpoints outboard of the wheel wells capable of taking a 250 lb (113 kg) bomb under each wing.
Apart from early Spitfires Mk. IX converted from Mk. Vc airframes, the undercarriage indicator pins were not used on this or any of the later Spitfire marks.
Comparison of armament layout between type A (middle) , B
(top) and C (bottom) wings on Spitfire Mk. V.
Note the difference in the placement of inner .303" Browning on C wing.
[Crown Copyright]
Internal structure of the Type C wing as fitted to the
Spitfire Mk. VIII.
The leading edge fuel tank was peculiar to this mark and was not mounted on
Spitfires Mk. V and IX.
Interestingly, both this and the subsequent drawing (produced by
Supermarine) of the Mk. VII show the downward identification lamp. However,
this item was deleted in the
Mk. VII & VIII production, by modification No. 746 issued on 1 May 1943.
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Corresponding structural drawing of the Spitfire Mk. XIVc
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