A crash which killed two fighter pilots in the Cairngorms has been partly blamed on a military air traffic controller, BBC Scotland has learned.
Both pilots were killed in the crash in the Cairngorms
The official RAF inquiry reached its conclusion even though the controller was cleared of causing the deaths by an earlier RAF court martial.
Two US pilots from Suffolk died when their F-15 jets crashed into Ben Macdui on a low flying exercise in 2001.
The report concludes they accepted an unsafe air traffic control instruction.
The deaths of Lieutenant Colonel Kenneth Hyvonen and Captain Kirk Jones, who were based at RAF Lakenheath, have been scrutinised several times.
The original RAF Board of Inquiry was suspended pending the court martial of Malcolm Williams, the air traffic controller at RAF Leuchars who gave flight descent information to the two US planes shortly before they crashed.
The RAF court martial cleared Flt Lt Williams of causing the deaths of the two pilots.
A US Air Force inquiry then concluded the American pilots made the first mistake, following confusion about terminology with the RAF controller.
Now the findings of the reconvened RAF Board of Inquiry conclude the crash happened partly because the pilots accepted an air traffic control instruction that was clearly unsafe.
A spokesman for the Ministry of Defence said it was not the role of a Board of Inquiry to apportion blame, and it marked the closure of an unfortunate incident for the RAF.
The F-15 pilots were flying in variable cloud on a low altitude training mission and were lost from radar during an air traffic control handover on 26 March, 2001.
Lieutenant Colonel Hyvonen, 40, and Captain Jones, 27, were killed instantly when their aircraft crashed while on a low flying exercise from RAF Lakenheath.