I was just reading about Aircraft Conditiong Systems and found that, the A.C. mechanism begins with compressor in the engine. Do these compressor also work the way in which AC/Refrigerator's compressor do? If they do, then Freon Gas Leaks should be something happening atleast once in a long period .. They are pretty common with household Air conditioning system.So, does this happens? I have never really heard of something like this happening to an aircraft..
Large aircraft use air conditioning packs (air-cycle machines) which uses only air, compressors and heat exchangers to cool/heat the air. There is no freon involved.
While transport-category jets tend to use air-cycle machines like ratchet freak mentioned some light airplanes are available with "standard" (freon heat-pump) air conditioners.
These have the same refrigerant-leak problems as your typical car air conditioner as seals age, pipes crack, etc.
These air conditioners are also not particularly popular accessories because they add weight and mechanical complexity to the aircraft (I don't think I've ever seen a plane with one installed in person, though I know a few folks over on the Piper forums who have the factory air conditioning in their planes).