As a fellow Pinnacle Pilot and former child support payer...
1... get out of the same state the order was filed in. Yes. move... in the same state the courts tend to favor the woman. IN different states your state is obligated to protect your butt.
2... file a petition with the courts (in the state with the order), usually through the probation office. It is free and you can do it yourself.
3... put in a petition for a reduction of wages, claim hardship
4... in 2-3 months you will get your court date, ask for teleconference it is allowed under title IV. it may take a few more weeks thereafter.
5... you can have your teleconference with either your lawyer ar at the child support office of your state. Believe it or not, those people in your new state will be helpful.
6... by federal law, they can only garnish so much, in certain state the limit can be lower. Fair credit act limits how much can be garnished. the problem is whatever you cannot pay will become arrears and that can land your butt in jail.
7... don't panic, be calm and document out the heck of your expenses. Go overboard, include the monthly oil changes for your car, the wear and tear on your car, parking.. you HAVE to get your expenses up, way up... By title IV there is a mandatory formula they use. In a nut shell they have to take the net income of both parents and then assign how much each can afford. There are federal guidlines on the max amount they can take for 2 children. I think it is 25% of disposable income..
8... ALPA cannot do anything for you, sorry but it is not contractual and they only way ALPA can is if they try to take your pilots license and in some states they can "attempt" to do that for failure to pay.
9... finally.. .and sadly.. don't offer any more money to the mother, not until this is cleared. Every penny you give does not count under the eyes of the law if it did not go through the child support agency.
to give you a "rough" idea...
I started with $25 per week, it was sweet. I was raised to $120 per week, then they went for the gold at got $375 per week. I filed hardship (myself) and got ir reduced to $105 per week, then filed hardship again (myself) and got it to $85, then $50, and finally it settled at $55 per week.
My lawyer got me the $25.00 per week, the rest were on my own. Also by law every 3 years they can adjust the payment based on COLA. So... if you are heading to upgrade, you bring her back into court and get a reduction on FO pay then upgrade. The way the system works if you are in different states you can work to your advantage. If she does not show for your court dates (and most don't), you win by default and then it will cost her to bring you back in. At one point I got it to my ex that it was costing her more to fight that what it was worth. They realize real quick when you get the order cut in half or more and they realize how much they paid to get their tails beat.
Been there done that... it sucks to be on the wrong end in a child support case.. let me tell you after 21 years, I am happy it is behind me and I wouldn't wish it on my worst enemy...