TAMPA — The future of Tampa International Airport came into sharper focus at Thursday's aviation board meeting: Officials released proposals for expanding the third-floor terminal and building a fifth airside to handle international flights.They're the latest additions to the airport's new master plan. They're also another nail in the coffin of the old master plan, an outdated and expensive scheme that called for erecting a new terminal north of the old one."This is a totally new concept, a new beginning, a new thought process of how we're going to use our main terminal," said Dr. Joseph Diaco, a board member, "without spending a billion dollars.''The final designs will be unveiled in March, along with the more humble price tag.The Hillsborough County Aviation Authority board, which oversees the airport, got its first look at facets of the new master plan in October. Those ideas called for adding more aviation repair facilities in the eastern quadrant and an automated people mover that would connect the terminal to a new consolidated rental car facility and retail center in the southern quadrant.Now it's the main terminal that's being rethought:• A new Airside D will be built along the northwest corner of the terminal, between Airsides C and E. The third floor will contain 16 gates for future international flights. Airside C will also be expanded.• The four corners of the third-floor terminal, where passengers board the airside trams and wait for arrivals, will be expanded.The north side will also be built out to accommodate the new Airside D and create a joint security screening area for Airsides D and C. The floors under the new security area will house customs and immigration. But the new footprint may encroach upon the Tampa Airport Marriott. The airport may need a new hotel, too.• A station for the new tram to the rental car facility will be built on the east side, between Airsides A and C.• New technology would streamline the ticketing and baggage area, freeing space.The airport, which currently handles 16.8 million passengers annually, wants to expand its existing facilities to handle a projected 34.7 million by 2041 without building a new terminal.But the terminal likely won't see any changes for a decade or two. The new rental car facility and other southern improvements will probably take place first within the next few years. The next public workshop on the new master plan will be at 6 p.m. Wednesday at the Seminole Heights Garden Center, 5800 N Central Ave.The aviation board also voted Thursday to hire Van Scoyoc Associates Inc. to a three-year, $500,000 contract to lobby the federal government on its behalf. The board wants the lobbyist to help with federal funding and to persuade the government to reimburse $93 million of the $124 million the airport spent on a system to detect explosives in luggage after Sept. 11, 2001.Jamal Thalji can be reached at [email protected] or (813) 226-3404.