A report by the UK’s National Audit Office (NAO) has listed some risks arising from the decision by UK Ministry of Defence (MoD) to switch its Joint Strike Fighter selection from the F-35B STOVL (short takeoff and vertical landing) version to the F-35C carrier version.
The decision was part of a defence review that delayed the in-service date of one of two new aircraft carriers to which the MoD was already fully committed, until 2018.
The other new carrier will be kept in reserve or sold.
The UK provided much STOVL expertise and nearly $4 billion to help develop the F-35B.
No firm cost to convert the carriers for “cat and trap” operations has yet been specified, the NAO report notes.
The industrial consortium led by BAE Systems that is building the carriers, at a cost of more than $8 billion, has tentatively estimated $800 million to add steam catapults to one carrier, or $1.280 million to add the new electromagnetic aircraft launch system (EMALS).
The US Navy is developing EMALS for service on its new carriers beginning in 2016, but there are technical risks and safety issues, according to the NAO.
Moreover, the F-35C design has been optimized for Nimitz-class carriers.
In adapting the type to the new British carriers, there could be issues with recovery speeds, fatigue strength and airframe life, the report claims.
And because the F-35C (unlike the F-35B), needs a fully cleared carrier deck to land, a buddy-type air refuelling system must be developed and added to British F-35Cs in case of a blocked deck. (The US Navy plans to use F-18s to air-refuel its carrier-based F-35Cs.)
The UK Royal Air Force is also planning to operate the F-35 as a land-based strike aircraft.
The report notes that one advantage of switching to the carrier version is greater combat radius, 650 nm versus 480 nm for the STOVL version. (The F-35 program office has recently revised these values downwards to 615 nm and 469 nm, respectively.)
The more spacious internal weapons bay is another plus for the F-35C – Free Republic.