Originally Posted by peterperfect
31-03-76 XV669 BL/410 Sea King HAS1 820 Sq RN ditched in the English Channel off Portland
PP,
The side numbers on RN cabs are the last two digits of the three digit number. The first is applicable to all aircraft of the (Carrier) Air Group, the second digit the Squadron allocation, and the last the aircraft number.
Ark Royal had all starting with 0, Eagle started with 1, etc. 824 was therefore 050 - 056 (7 aircraft), 826 was 140 - 145 (only six aircraft) when part of Ark's and Eagle's air groups. 820 would have had side numbers 10 - 13, IIRC, as a 4 aircraft squadron on Blake, so the photo wouldn't have been the 820 cab.
eg recovery of 051, an 824NAS HAS1: