"In early 1940 Spitfire Is of
54 and
66 Squadrons were fitted with Rotol manufactured wide-bladed propellers of 10 ft 9 in (3.27 m) diameter, which were recognizable by a bigger, more rounded spinner" .....
Seems to be a widespread quote, no idea where it originated.
The following 22 N serials are marked in the RAF contract cards with the comment Rotol Airscrew.
N3030 (probably flying in mid September 1939 but delivered 5 October)
October 1939, N3096, N3097 (Contract B10783/39 or B10983/39 versus the production contract 527113/36), N3103, N3104, N3110, N3111
November N3122, N3124, N3130, N3160, N3171 to N3174, N3176, N3180, N3183, N3185, N3187, N3188
December N3184.
N3171 AMDP, central flying school, rest to 54 squadron
There is a report Vickers documents add R6977, 79 (both 609 sqn), 81 (72 sqn), 93 (610 sqn), 95 (64 sqn), R7015, 17, 19 (all 3 54 sqn), 20 (609 sqn), 21 (54 sqn), none of these are noted as having Rotol propellers in the Contract Cards, official delivery dates between 19 and 25 July 1940.
66 squadron switched from Gauntlet to Spitfire in the final quarter of 1938, receiving K serials. Then received new N serials in September 1939 and mostly held them through 1940 until lost or damaged. In April 1940 66 squadron was using N3027, 28, 29, 32, 33, 35, 37, 41, 42, 43, 44, 46, 47, 48, 49, N3106, 21. For the quote to be true time wise the 66 squadron Spitfires issued in September 1939 were converted.
late 1938 Rotol Trials in the Spitfire
1 February 1939 Spitfire modification #62 'Replace DH2 pitch propeller with Rotol C/s' (not possible until mid year when Merlin III fitted)
September 1939 start of batch of 22 Rotol equipped Spitfires.
22 June 1940 crash conversion program ordered, from DH 2 pitch to constant speed.
3 July 1940 Spitfire modification #76 'Introduce DH C/s propeller'
30 December 1941 Spitfire modification #279 'Fit DH Hydromatic propeller'