Can anyone give me advice going from being an Air Force SSgt 3D1X1 with 9yrs in and applying to be a Army Warrant Officer (255N) ?

Last time I checked this Army WO MOS was in critical need, and I know a lot of enlisted guys from other branches have gone Army Warrant. I would say your first step is finding a Warrant Officer Strength/Accessions Manager. There are links on the Army recruiting site, but if all else fails, contact an Army recruiter and he/she should be able to put you in contact with the right people. Good luck!

My best advice is be ready for a very long packet process. Most guys I know have taken about a year to get it all done before boarding.

I did that very thing. I was an Air Guard E6 ready to make E7. The process took over a year and a half. I had to get several waivers, one for rank and one for feeder MOS. Army wanted me to go to Rucker for a year for aviation maintenance warrant training. I did aircraft maintenance in the guard. Since I couldn't leave my civilian job for Army training the Army said they would take me for my civilian background. I worked as an Network Operations Telco Technician for a Bell company. When my package was finally accepted and I was accepted for WOCS I had zero tactical experience for WOCS training. Adapted and overcame and screwed up by the numbers at that in WOCS. However, my strong points got me through training and I was pinned. I never looked back and enjoyed my nine years as a warrant. Best advice for you at this point is 1) perserverance.....don't get discouraged and give up and 2) Advocate..........at least when I went through this it seem the Air Force and the Army folks didn't communicate with each other. You pretty much have to do it all by yourself. Preparing the WOCS package seemed to take forever to the point I thought that was part of the process to see if you really had an honest desire to be a Warrant. In the end it was worth it and I happily retired after 21 years total service. Hope this helps.........