The UK Ministry of Defence has been sharply criticised by MPs over its management of equipment procurement programmes, describing it as being in a "cycle of failure".
The House of Commons public accounts committee says that poor or uninformed decision making had led to massive cost overruns or delays to major projects and the consequent early retirement of a number of aircraft types including the BAE Systems Harrier.
It singles out the acquisition of the Eurofighter Typhoon, BAE Nimrod MRA4 and the Raytheon Systems Sentinel R1 surveillance aircraft as having been particularly poorly managed, with a result that difficult decisions had to be taken further down the line, leaving gaps in the MoD's capabilities.
The committee describes the 2004 decision to remove £1 billion ($1.6 billion) of funding for the purchase of 88 Tranche 3 Eurofighters, on the assumption that other partner nations would follow suit, as "over-optimistic".
"It was not supported by the contract already in place," it adds.
An additional £2.7 billion was spent on the project in 2009, which included the purchase of 16 extra aircraft, says the report. It adds: "The department failed to convince us that the decision to purchase the 16 additional aircraft was a military one rather than a contractual one which it should have foreseen.
"To afford the extra Typhoon aircraft, the department has had to find savings in other equipment areas, including from the [Panavia] Tornado and Harrier fleets."
The cancellation of the Nimrod MRA4 and the planned early retirement - around 2015 - of the Sentinel R1, contained within the Strategic Defence and Security Review, will cost the UK taxpayer around £5 billion, it notes, with the MoD also accepting "greater operational risk" as a result.
However, it says that the MoD does appear to have learned from past mistakes, with the recent contract for the Lockheed Martin F-35 Joint Strike Fighter showing greater flexibility than previous examples.
The committee calls for better management and greater accountability at the MoD.