Pilots and staff at a Lincolnshire RAF base have been briefed by military chiefs about possible redundancies.
The Ministry of Defence said the number of student pilots currently involved in training will be cut by up to 170 across three sites in the country.
About 20 fast jet pilots, 30 helicopter pilots and 50 transport aircraft pilots are believed to be facing the axe.
The number of trainee pilots at RAF Cranwell likely to be affected has not been revealed.
Plans are 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."