This report provides an overview discussion on the modernization of U.S. military tactical aircraft, meaning fighter aircraft, strike fighters, and attack planes. Tactical aircraft are a major component of U.S. military capability, and account for a significant portion of U.S. defense spending. In early 2009, the Air Force, Navy, and Marine Corps collectively had an inventory of about 3,500 tactical aircraft. Current efforts for modernizing U.S. tactical aircraft center on three aircraft acquisition programs—the F-35 Joint Strike Fighter (JSF) program, the Air Force F-22 fighter program, and the Navy F/A-18E/F strike fighter program. Program-specific issues for Congress in FY2010 relating to the F-35, F-22, and F/A-18E/F include the following: Whether to approve or reject the administration's proposal to terminate program for developing an alternate engine for the F-35. Whether to whether to approve the administration's request to end F-22 procurement at the 187 aircraft that have been procured through FY2009, or reject that proposal and provide funding in FY2010 for the procurement of additional F-22s in FY2010 and/or subsequent years. Whether to approve, reject, or modify the Navy's FY2010 funding request for procurement of nine F/A-18E/Fs, and whether to approve a multiyear procurement (MYP) arrangement for FY2010-FY2014 for procuring F/A-18E/Fs (and also EA-18Gs, which are electronic attack versions of the F/A-18E/F). These program-specific issues, as well as FY2010 legislative activity relating specifically to the F-35, F-22, and F/A-18E/F programs, are covered in detail in the following CRS reports: CRS Report RL30563 on the F-35 program. CRS Report RL31673 on the F-22 program. CRS Report RL30624 on the F/A-18E/F program. This CRS report discusses and presents FY2010 legislative activity on issues relating to U.S. tactical aircraft in general. For several years now, a central issue relating to tactical aircraft in general has been the overall affordability of the Department of Defense's (DOD's) plans for modernizing the tactical aircraft force. A second key issue concerns the future of the U.S. industrial base for designing and manufacturing tactical aircraft. In general, the term tactical aircraft refers to shorter-ranged combat aircraft that can conduct missions up to several hundred miles away from their home bases without need for in-flight refueling. Tactical aircraft tend to perform their missions within a single regional theater of operations, which is why they are also sometimes called theater-ranged aircraft or simply theater aircraft. The term strategic aircraft, in contrast, usually refers to larger and longer-ranged Air Force B-52, B-1, and B-2 bombers that are designed to conduct missions involving very long (including intercontinental) flights to their intended areas of operations (though they can also be used for missions that take place within a single theater of operations). Although the above distinction between tactical and strategic aircraft can suggest that the term tactical aircraft refers to virtually all types of shorter-ranged aircraft, in practice the term is used primarily to refer to fighters, strike fighters, and attack planes. Fighters, which usually have an "F" designation (e.g., F-22), are designed primarily for air-to-air combat, though they can have some air-to-ground combat capability as well. Strike fighters, which can have either an "F" designation (e.g., F-35) or an "F/A" designation (e.g., F/A-18E/F), are dual-role aircraft that are designed to have a substantial capability in both air-to-ground (strike) and air-to-air (fighter) operations. Attack planes, which usually have an "A" designation (e.g., A-10) are designed primarily for air-to-ground operations. The term tactical aircraft is often shortened to tac air (also spelled tacair). Air Force tactical aircraft operate from land bases and are conventional takeoff and landing (CTOL) aircraft. Navy tactical aircraft are CTOL aircraft that have features permitting them to operate from aircraft carriers. Marine Corps aircraft are operated from both Navy ships and land bases, including expeditionary land bases with short runways. Some Marine Corps tactical aircraft are vertical/short takeoff and landing (VSTOL) or short takeoff, vertical landing (STOVL) aircraft. Tactical aircraft are used to perform a variety of missions. Fighters engage primarily in air-to-air combat so as to establish and maintain air superiority in a theater of operations. Attack planes focus on air-to-ground combat operations, including close air support (CAS) for friendly ground forces engaged in battle, battlefield air interdiction (BAI) against enemy forces that are behind the front lines, and deep interdiction (also known as "deep strike") against the enemy's military, political, and industrial infrastructure. Strike fighters engage in both air-to-air and air-to-ground operations. Tactical aircraft can also be used for other operations, including surveillance and reconnaissance operations. The Air Force currently operates new F-22 fighters and the following older aircraft types: F-15 fighters, F-15E strike fighters (a version of the F-15 with enhanced air-to-ground capabilities), F-16 fighters (which are actually strike fighters), and A-10 attack aircraft. The Navy currently operates older F/A-18A through D strike fighters and newer and more capable F/A-18E/F strike fighters. The Marine Corps' operates two older types of aircraft: F/A-18 A-D strike fighters and AV-8B VSTOL attack planes. Table 1 , which presents figures from a May 2009 Congressional Budget Office (CBO) report, shows approximate numbers of U.S. tactical aircraft in early 2009. As can be seen in the table, DOD in early 2009 had a total inventory of about 3,500 tactical aircraft, of which about 2,375 were in the Air Force and about 1,125 were in the Navy and Marine Corps. Current efforts for modernizing U.S. tactical aircraft center on three aircraft acquisition programs—the F-35 Joint Strike Fighter (JSF) program, the Air Force F-22 fighter program, and the Navy F/A-18E/F strike fighter program. The F-35 Joint Strike Fighter (JSF), also called the Lighting II, is a new strike fighter being procured in different versions for the Air Force, Marine Corps, and Navy. The F-35 was conceived as a relatively affordable fifth-generation strike fighter that could be procured in three highly common versions for the three services, so that the services could avoid the higher costs of developing, procuring, and operating and supporting three separate tactical aircraft designs to meet their similar but not identical operational needs. The F-35 program is DOD's largest weapon procurement program in terms of total estimated acquisition cost. Current DOD plans call for acquiring a total of 2,456 JSFs for the three services at an estimated total acquisition cost (as of December 31, 2007) of about $246 billion in constant (i.e., inflation-adjusted) FY2009 dollars. Procurement of F-35s began in FY2007. The Air Force is procuring the F-35A, a conventional takeoff and landing (CTOL) version of the F-35, as the replacement for the service's F-16s and A-10s. The F-35A is intended to be a more affordable complement to the Air Force's new F-22s. The Marine Corps is procuring the F-35B, a STOVL version of the F-35, as the replacement for the service's F/A-18A-D strike fighters and AV-8B Harrier VSTOL attack planes. The Navy is procuring the F-35C, a carrier-capable CTOL version of the aircraft, and plans to operate carrier air wings in the future featuring a combination of F/A-18E/F and F-35C strike fighters. The administration's proposed FY2010 budget requested funding for the procurement of 30 F-35s, including 10 F-35As for the Air Force, 16 F-35Bs for the Marine Corps, and four F-35Cs for the Navy. The Air Force F-22 fighter, also known as the Raptor, is the world's most capable air-to-air combat aircraft. The F-22 is a fifth-generation aircraft that incorporates a high degree of stealth, supercruise, thrust-vectoring for high maneuverability, and integrated avionics that fuse information from on-board and off-board sensors. Procurement of F-22s began in FY1999, and a total of 187 have been procured through FY2009, including 24 in FY2009. The administration wants to end F-22 procurement at 187 aircraft, and the administration's proposed FY2010 budget did not request funding for the procurement of additional F-22s in FY2010. Supporters of the F-22 want to continue procuring the aircraft in FY2010 and/or subsequent years, toward an eventual goal of 243 to 250 (or more). The F/A-18E/F, also known as the Super Hornet, is a Navy strike fighter. It is larger, more modern, and more capable than the earlier F/A-18A-Ds, which are known as Hornets.