Editing Westland Whirlwind (fighter) (section)

==Variants==
'''P.9 prototype'''
:Single-seat twin-engine fighter aircraft prototype. Two built (L6844 and L6845), can be distinguished from later production samples by the mudguards above the wheels (as did the first production sample, P6966), the exhaust system and the so-called 'acorn' on the joint between fin and rudder. L6844 had a distinctive downward kink to the front of its pitot tube, atop the tail not seen again in following models. L6844's colour was dark grey. L6844 had opposite-rotation engines, L6845 had engines that rotated in the same direction; this carried over to production machines.

'''Whirlwind I'''
:Single-seat twin-engine fighter aircraft, 400 ordered, 116 built (2 prototypes and 114 production versions).

'''Whirlwind II'''
:Single-seat twin-engine fighter-bomber aircraft, fitted with underwing bomb racks, were nicknamed "Whirlibombers". At least 67 conversions made from the original Mk I fighter.

'''Experimental variants'''
A Mk I Whirlwind was tested as a night fighter in 1940 with No. 25 Squadron.
The first prototype was armed with an experimental twelve 0.303 (7.7&nbsp;mm) machine guns and another one 37&nbsp;mm cannon.<ref name="Robertson p. 16.">Robertson 1970, p. 16.</ref><ref>Green 1961, p. 125.</ref>
<!-- Exhaust "muffs" were fitted to conceal flames, as well as landing lights suitable for night flying.<ref>[http://www.flightglobal.com/pdfarchive/view/1942/1942%20-%200500.html p196] ''Flight'' 5 March 1942.</ref>   -->

'''Merlin variant'''
Westland proposed fitting Merlin engines in a letter to Air Marshal [[Sholto Douglas, 1st Baron Douglas of Kirtleside|Sholto Douglas]].<ref>[http://discovery.nationalarchives.gov.uk/details/r/C506723 PRO/NA air 16-326 page 82A]</ref> The proposal was rejected but Westland used the design work already performed in developing the [[Westland Welkin|Welkin]] high-altitude fighter.