Customs and Excise officers are issuing guidelines to Britain's 220 clubs on how to vet new members, and ways to detect suspicious individuals trying to hire planes. Light aircraft schools and flying associations have also been alerted.
The rewards for smugglers can be vast. Heroin, with a street price of pounds 74 a gram, accounts for 80 per cent of all drugs seized from light aircraft.
The gangsters also trade in softer drugs. Recently Dutch officers found 50 kgs of amphetamines and 15 kgs of cannabis in a pre-flight check on a Beech Baron aircraft hired in the UK.
And 150 kgs of cannabis were also found on a Cessna 150 abandoned in a farmer's field after flying from Holland.
Customs investigators say the majority of those arrested appear to have legitimate credentials but are linked to drug smuggling organisations.
Owning a private pilot's licence is no longer the preserve of the rich. Learning to fly costs from pounds 95 per hour for a single- engined craft, and hiring a plane is as little as pounds 50 an hour.
Pilots need between 45 and 50 hours flying time for a licence and can hire a plane after a medical check and a supervision flight with a club pilot.
Paul Kirkup, spokesman for the Customs' anti-drugs alliance programme which works with the flying community to try to combat crime, believes smugglers are capitalising on "less than vigorous" vetting procedures at the clubs.
"Our intelligence shows that organised gangs of Russian and Chechen mafia are involved as well as other groups," he said. "This is indicated by the backgrounds of those arrested. These are very intelligent criminal gangs, not just ordinary thieves.
"These people spend a few months to gain respectability and to get the confidence of the people in a club. This then gives them free licence to use a plane and then take it back and forwards to the continent. Customs officers are educating clubs about being more vigilant but we are operating on limited resources and clubs must think about tightening up their vetting procedures."
There are several ways to distinguish between the men in Pringle sweaters who just want to enjoy the thrill of flying and those with more devious intentions, says Mr Kirkup.
Clients carrying large amounts of money, who pay cash to hire an aircraft or who are deliberately vague about an intended trip, should be treated with suspicion.
There are now 8,500 light aircraft in this country, which represents a 20 per cent increase in 10 years. The Denham School of Flying in Buckinghamshire has 150 members paying pounds 141 a year. Ruth Dowie, the operations manager, says the school has cracked down after Customs' warnings on people wanting to use the club.
"We are certainly careful of dodgy characters who are paying with large amounts of cash," she says. "It's a small airfield here and it's difficult to check what is going in and out. We are a school but it's very much a club atmosphere. People want to socialise so we have parties and barbecues. It would be very easy for someone to come in and befriend us, andthen betray us."
Martin Robinson, chief executive of the Aircraft Owners and Pilots Association (Aopa), admits that it is difficult to screen people because criminals would naturally lie about their intentions.
He said members of Aopa were already reporting suspicious behaviour to a confidential drugs line, adding: "There is no real reason why a club should know exactly what a person's business is. It is difficult if Mr Smith says he is going to visit relatives in France and disappears for a few days."Reuse content