The number and type of helicopters used by the Royal Navy, Army Air Corps and Royal Air Force which are in the Forward fleet and considered fit for purpose are detailed in the following table. Forward fleet aircraft are those that are available to the front-line command for operational and training purposes (i.e. those not in depth maintenance). Aircraft defined as fit for purpose are those considered capable of carrying out their planned missions on a given date.
Helicopter type In service (total fleet) Average number of aircraft in Forward fleet Percentage of total fleet in Forward fleet Average number of aircraft fit for purpose (FFP) FFP as a percentage of total fleet FFP percentage of Forward fleet Royal Navy Sea King Mk 4/6c 42 31 74 15 36 48 Lynx Mk 3/8 63 42 67 29 46 69 Merlin Mk 1 38 24 63 20 53 83 Sea King Mk 5 15 11 73 7 47 64 Sea King Mk 7 13 9 69 7 54 78 Army Air Corps Apache AH Mk 1 67 51 76 24 36 47 Lynx Mk 7/9 96 54 56 31 32 57 Gazelle Mk 1 67 45 67 n/a n/a n/a Augusta A109 4 4 100 4 100 100 Royal Air Force Chinook Mk 2/2a 40 29 73 19 48 66 Puma Mk 1 38 23 61 16 42 70 Merlin Mk 3/3a 27 17 63 10 37 59 SAR Sea King Mk 3/3a* 25 17 68 12 48 71
The figures shown are the average for the month of April 2008 (with the exception of the search and rescue Sea King Mk 3/3a data, which cover March 2008 due to technical problems). The number of helicopters fit for purpose will vary from day to day due, primarily, to routine maintenance requirements. Operational capability is measured in terms of flying hours rather than the number of airframes available.