Pilots and staff at a North Yorkshire RAF base have been briefed by military chiefs about possible redundancies.
The Ministry of Defence (MoD) said the number of student pilots involved in training would be cut by up to 170 across three sites in the country.
It is not currently known how many trainees at RAF Linton-on-Ouse will be made redundant.
The MoD said all trainees would be individually assessed over the coming months.
Those training as fast jet pilots, helicopter pilots and transport aircraft pilots will all be affected by the cuts which are part of plans to reduce RAF personnel by about 5,000 to a total of about 33,000 by 2015.
An MoD spokesperson said: "Due to the reduction of the RAF's aircraft fleet the number of student pilots in the Flying Training Pipeline will be reduced by up to 170.
"There will be some redundancies but we will, where possible, consider alternative roles for these trainees.
"This will not have an impact on operations."
Aviation expert Sean Maffett said: "All of these people are extremely dedicated, they're all highly motivated, they've already proved that they've got lots of determination and guts and now they're finding themselves in some doubt as to whether it's ever going to happen."
There are also some concerns that a reduction in personnel at the RAF base could impact on the local economy.
Jacqui Weedock, landlady of the nearby College Arms, said: "They come in, they have meals and drink, it would be a shame to the whole village economy if the base was to go or decrease any further."