Not to piss on anyones parade, but when the timelines are posted for IOC for new aircraft, they tend to be VERY optimistic..........
IOC does not mean all the old ones are gone in a flash.
Initial Operational Capability (IOC) is typically defined as the first deployable unit fully equipped, trained and ready to deploy so as implied above, the transition to a new airframe will take quite some time. The reason it slides in most cases is generally due to developmental delays. The most crucial juncture is OPEVAL (Operational Evaluation) conducted under auspices of COMOPTEVFOR (Commander Operational Test and Evaluation Force) that owns a number of Operational Test VX squadrons (such as VX-1, VX-9, part of HMX-1 as well as a specialized unit for MV-22). COMOPTEVFOR makes a crucial judgement on Operational Effectiveness and Suitability BEFORE Full Rate Production (FRP) so the transition doesn't start in earnest until they report up the chain (direct to VCNO and in case of major programs and all aircraft all major programs) to OSD Director of Operational Test and Evaluation (DOT&E). NAVAIR (using a collective term for the PEO Program Offices) won't send an aircraft to OPEVAL unless they are sure it will pass and COMOPTEVFOR won't test it unless it is a production representative configuration so therein lies the rub and a big reason why programs slide. If there are developmental issues, the aircraft will stay with Developmental Test (DT) squadrons (such as VX-20, HX-21, VX-23) until it is ready for prime time and certified by the cognizant Program Executive Officer (PEO) as ready for Operational Test (by means of a Operational Test Readiness Review (OTRR)).
That said, the whole plan is breifed to Congressional annually and the Plan of Action and Milestones (POA&M) are part of "legal" testimony to the hill by DoD(available on-line). That includes the IOC and expected date for FRP and a host of other acquisition programmatic dates. There isn'y hardly any wiggle room and any changes have to be briefed up the acquisition oversight chain to the Assistant Secretary of the Navy for Research, Development and Acquisition (as well as to OSD AT&L if a ACAT 1D) so the contractor can't set their own IOC. They know better and should be echoing what is briefed to Congress. Congressional Staffers working for the 4 big Defense Committees/Subcommittees put the Program Office and Requirements Officer through a grueling cattle call every year (about to start for the FY08 Budget that was sent to the Hill last week) and these dates are subject to comparison with what was submitted last year along with costs, developmental issues and just about everything under the sun. That happens face-to-face away from the hill while the big dogs trudge over to the hill and make formal statements (about to start) to the committees (watch for it on CSPAN) and field questions. It's the staffers who actually mark up the programs (adding, deleting or leaving funds intact) for Committee and then Floor votes. PM me if you want the links, but suffice to say there are places to go to get the dates (updated annually in early Feb) that are what the PM signs his career away on in his inputs through OPNAV/DoN to Congress. "And that's all I have to say about that".
