I believe that is a grey area. If you get furloughed and then you come back I believe it is still current. You are still employed during the furlough. You may run into problems if you tried to use your ATP written while furloughed though because the reg may say that you have to be current. You would have to check on that though. Also, some examiners treat the written different ways when it comes to working for 121 carrier. If you go for your ATP certificate with ALL ATP's, they will make you retake the written if yours is only current because you are employed by a 121 carrier. If you are within the 24 months, then you wouldn't be required to retake it. Now there are a few examiners out there that interpret the reg a little differently and they will not make you retake your written as long as you can provide a letter from your 121 carrier that states you are currently employed with them.

Hope that helps.