asked the Secretary of State for Defence why length of "man's service" is reckonable from the age of 18 years in the Royal Navy but from the age of 17½ years in the Royal Air Force and the Army.
Man's service, in the sense of qualifying service for pension and completion of engagement, is reckoned from age 18 in all three Services, although soldiers and airmen may count their service for gratuity from the age of 17½.
This difference stems from the fact that, until 1962, the Army and RAF reckoned engagements from age 17½ whereas the 12 years' qualifying service for a gratuity was counted from age 18. This meant that it was possible for a soldier or airman to complete his engagement without qualifying for a gratuity. To overcome this problem it was decided to count qualifying service for gratuity also from age 17½.
This problem did not arise for the Royal Navy where the rules for reckoning time for engagements and gratuities were already in line.