The four modern Rotax engines were taken on 13 June at South Hams Flying Club in Devon.
Club chairman John Stothart said around 45 aircraft engines had been stolen across the country in last two years.
Pilots said they feared the crime was an "emerging threat in aviation". Devon and Cornwall Police have launched an investigation.
The owners of Halwell airfield, where the club operates, say security is being stepped up in the area.
They added that there is a market for the aircraft engines in Eastern Europe because they have serial numbers and log books which are required when selling them in the UK.
Ian Holden, who had his engine stolen, said: "The danger is that this will change the attitude of a lot of pilots because they will have this worry and its it going to happen again?
"This is in a sense a new departure in aviation."
Mr Stothart said the thieves appear to have cut hoses and cables with a serrated knife then chopped off the engine mount before stealing the large pieces of machinery.
They were insured and the aircraft have been sent away for repair.
Det Con Emma Youngman, from Devon and Cornwall Police, said they had been made aware that several similar thefts across the country between 2016-17.
She added: "We've established a database of where the thefts occurred and I'm already in touch with the other forces to establish if they have any information we can use to try and locate the offenders."
Light aircraft engines worth £80,000 have been stolen from planes during a single raid at a rural airfield.