You don't read potentially life-changing documents?
You've obligated yourself to 4 weeks of training if you are lucky enough to get to OCS. Anything beyond that and its up to you. Provided you make it through OCS, TBS, etc and get your wings, depending on which track you select you will owe whatever amount of years it says on your contract. Supposedly it has changed to 8 years all around but when I signed my contract in 2009 it said 6 years for rotary and tilt rotor, 8 years for jets and hercs.