A number of sealants are provided that are resistant to degradation by aircraft fluids. In some embodiments, the sealants are resistant to degradation by Jet A fluid and at least one of the three types of hydraulic fluids typically used in aircraft. These embodiments are also typically cure in place from a two part polyurethane or polyurea mix, with cure to a visibly clear coating. In some embodiments, they may be sprayed on an aircraft surface or applied by hand (brush or injectable). In other of these embodiments, the sealants comprise, at least in part, a cured, soft, tacky polyurethane gel that is resistant to at least one of a synthetic hydrocarbon based or mineral oil based hydraulic fluid.