The armed forces face an "alarming" shortage of battlefield helicopters, a Commons committee has warned.
The Chinooks were meant to be in service in 1998
The Public Accounts Committee said the gap between the number of helicopters needed and those available to the MoD is between 20% and 38%.
The shortage was exacerbated by the MoD's £259m purchase of eight Chinook helicopters, which remain grounded.
The report also said shortfalls in other protection equipment could increase risks for service people.
The MPs branded the Chinook affair "one of the worst examples of equipment procurement that the committee has seen".
The committee also warned of shortfalls in helicopter protection equipment, nuclear, biological and chemical protection for aircrew, and communications capacity.
It said these problems could increase risks faced by the Royal Air Force, Army and Royal Navy, including overstretching available equipment and pilots.
The committee said as yet the equipment shortfall had not impacted on the successful conduct of operations - but had "adversely impacted" training in the UK.
The MPs noted that the MoD intended to spend £3bn over the next 10 years to enhance and replace the capability provided by the helicopter fleet.
But it added: "The Department did not, however, expect to eliminate the shortfall in battlefield support helicopter lift in its entirety."
The committee said the shortfall problem had been exacerbated by the Chinook saga, which began in July 1995.
The Chinook helicopters were grounded because they could be a risk to fly in cloudy weather because the software which enabled them to do this could not be properly tested.
The report said "Only 45 of 100 'essential elements' set out in the department's requirement were actually specified in the contract.
"The department was unable to say who was responsible for the flawed procurement of the Chinook Mark 3. No-one seems accountable when things go wrong, " it stated.
As of April 2004, the MoD had an overall fleet of 357 battlefield helicopters to support land, amphibious and Special Forces' operations.
The committee made a series of recommendations including that the MoD should consider creating a single organisation which would deem whether a helicopter is airworthy and fit to enter service.
Currently that is a responsibility of the individual services.
Committee chairman Edward Leigh, Tory MP for Gainsborough, said of the report: "It is simply disgraceful that the MoD has spent a quarter of a billion pounds of taxpayers' money on the botched procurement of eight Chinook helicopters that cannot be flown because the MoD can't determine if they're safe.
"The MoD urgently needs to work out whether the helicopters can be made fit for operations and how much this would cost the public purse, or whether there is any other good use for the helicopters aside from breaking them up for spares."
The report welcomed the 1991 move which saw the battlefield helicopters of the Royal Navy, Army, and RAF brought under a single Joint Helicopter Command (JHC).