The Civil Aviation Authority faces industrial action for the first time in 40 years in a dispute over pay.
Prospect union members plan a working to rule and an overtime ban from January 20.
A statement by the union said: “The extra hours that CAA members work beyond those they are contracted for are essential for the aviation sector.
“Removing these extra hours could have an impact on the industry and ultimately affect passengers.”
Prospect deputy general secretary Rachel Curley said: “Our members don’t want to take industrial action but they have been left with no choice after unacceptable tactics from the employer.
“There is still time to avoid industrial action which will be damaging for the industry.
“The CAA needs to restart good faith negotiations and come up with a fair and reasonable offer that our members can accept.”
The union claimed that the aviation regulator imposed a 3%-4% pay offer on staff after “going through the motions” of negotiating.
The offer was described as neither keeping pace with the industry nor civil service.
A CAA spokesperson said: “We continue to engage with our union colleagues and after prolonged discussions, it is disappointing that Prospect members have voted to take industrial action.
“Prospect members make up around one in five of our employees and we do not anticipate any disruption to the aviation sector, or any impact on our regulatory oversight activities or other safety critical work, as a result of this action.”