Tens of millions of pounds has been spent on recovery centres for wounded soldiers where beds are left empty, it has been reported.
The network of centres are funded by the British Army, in partnership with Help for Heroes and the Royal British Legion, to support injured military personnel and veterans.
Only around half of bedrooms at the two largest facilities were occupied by serving personnel between August 2013 and January this year, according to The Times.
Taxpayer and charity money has been pumped into the scheme without finding out what was needed, the paper reported.
Costs allegedly went from £70 million over four years to almost £350 million over 10 years to create five personnel recovery centres and a state-of-the-art sporting complex.
The army did not know how many wounded, injured or sick soldiers there were, making it hard to calculate demand for the centres, The Times said.
Lieutenant-Colonel Jonathan Sutton, acting chief of staff on the project, said: "The team used to joke how it was like trying to build an aeroplane while taxiing down the runway, someone had forgotten to bolt the wings on, air traffic control didn't know how useful a flight plan might be.
"A few, including myself, warned our senior officers. We were shouted at or just ignored."
He told The Times: "We were spending lots of other people's money — that people had biked, climbed, run and swum for — on bricks and mortar without a clear audit trail about how we got to this position.
"It really worried me and, of course, the costs kept on going up. I thought this was scandalous."
The project was founded in 2010 after public pressure to do more for troops injured in Afghanistan and Iraq.
But it was launched "before the requirement was fully understood", according to an internal review.
The report, by the Army Improvement Support Branch and released after a freedom of information request by The Times, said the focus of Help for Heroes on personnel wounded on operations "provided a significant impetus for the project".
An MOD spokesperson said: "The requirement for the Army Recovery Capability was identified in response to a growing need to look after our people differently.
"The need for this capability, including personnel recovery centres, was established by the MoD and was developed at some speed in partnership with H4H (Help for Heroes) and the Royal British Legion.
"There was a shared vision to meet the challenges of Iraq and especially Afghanistan.
"We believe what we have delivered is a significant achievement in an incredibly short period of time, which meets an enduring need and provides infinitely better support than was available previously.
"Inevitably in an unprecedented project of this complexity, aspects of implementation across units within the army have had to be adjusted – and greater numbers of wounded, injured and sick personnel are now using the PRCs during their recovery, alongside veterans who receive ongoing support from our charity partners."
The Royal British Legion is reviewing occupancy rates and claims it raised concerns over the scale of support needed during the early stages of the venture.
Help for Heroes told The Times figures for June and July showed "men and women with life-changing injuries or illnesses used over 70% of the rooms available".