The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engine, all-weather stealth multirole fighters. The fifth-generation combat aircraft is designed to perform ground attack and air superiority missions. It has three main models: the F-35A conventional takeoff and landing (CTOL) variant, the F-35B short take-off and vertical-landing (STOVL) variant, and the F-35C carrier-based Catapult Assisted Take-Off But Arrested Recovery (CATOBAR) variant. On 31 July 2015, the United States Marines declared ready for deployment the first squadron of F-35B fighters after intensive testing. On 2 August 2016, the U.S. Air Force declared its first squadron of F-35A fighters combat-ready.
The F-35 descends from the X-35, the winning design of the Joint Strike Fighter (JSF) program. An aerospace industry team led by Lockheed Martin designed and manufactures it. Other major F-35 industry partners include Northrop Grumman, Pratt & Whitney and BAE Systems. The F-35 first flew on 15 December 2006. The United States plans to buy 2,663 aircraft. Its variants are to provide the bulk of the crewed tactical airpower of the U.S. Air Force, Navy and the Marine Corps over the coming decades. Deliveries of the F-35 for the U.S. military are scheduled until 2037 with a projected service life up to 2070.
The United States principally funds the F-35 JSF development, with additional funding from partners. The partner nations are either NATO members or close U.S. allies. The United Kingdom, Italy, Australia, Canada, Norway, Denmark, the Netherlands, and Turkey are part of the active development program; several additional countries have ordered, or are considering ordering, the F-35.
The program is the most expensive military weapons system in history, and has been much criticized inside and outside government, in the U.S. and in allied countries. Critics argue that the plane is "plagued with design flaws", with many blaming the procurement process in which Lockheed was allowed "to design, test, and produce the F-35 all at the same time, instead of… [identifying and fixing defects before firing up its production line". By 2014, the program was "$163 billion over budget and seven years behind schedule". Critics also contend that the program's high sunk costs and political momentum make it "too big to kill".
Helmet-mounted display system
The F-35 does not need to be physically pointing at its target for weapons to be successful. Sensors can track and target a nearby aircraft from any orientation, provide the information to the pilot through their helmet (and therefore visible no matter which way the pilot is looking), and provide the seeker-head of a missile with sufficient information. Recent missile types provide a much greater ability to pursue a target regardless of the launch orientation, called "High Off-Boresight" capability. Sensors use combined radio frequency and infra red (SAIRST) to continually track nearby aircraft while the pilot's helmet-mounted display system (HMDS) displays and selects targets; the helmet system replaces the display-suite-mounted head-up display used in earlier fighters. Each helmet costs $400,000.
The F-35's systems provide the edge in the "observe, orient, decide, and act" OODA loop; stealth and advanced sensors aid in observation (while being difficult to observe), automated target tracking helps in orientation, sensor fusion simplifies decision making, and the aircraft's controls allow the pilot to keep their focus on the targets, rather than the controls of their aircraft.
Problems with the Vision Systems International helmet-mounted display led Lockheed Martin-Elbit Systems to issue a draft specification for alternative proposals in early 2011, to be based around the Anvis-9 night vision goggles. BAE Systems was selected to provide the alternative system in late 2011. The BAE Systems alternative helmet was to include all the features of the VSI system. However, adopting the alternative helmet would have required a cockpit redesign, but in 2013 development on the alternative helmet was halted because of progress on the baseline helmet.
In 2011, Lockheed Martin-Elbit granted VSI a contract to fix the vibration, jitter, night-vision and sensor display problems in their helmet-mounted display. A speculated potential improvement is the replacement of Intevac’s ISIE-10 day/night camera with the newer ISIE-11 model. In October 2012, Lockheed Martin-Elbit stated that progress had been made in resolving the technical issues of the helmet-mounted display, and cited positive reports from night flying tests; it had been questioned whether the helmet system allows pilots enough visibility at night to carry out precision tasks. In 2013, in spite of continuing problems with the helmet display, the F-35B model completed 19 nighttime vertical landings on board the USS Wasp at sea,by using the DAS instead of the helmet's built-in night vision capabilities, which offer at best 20/35 vision.
In October 2013, development of the alternate helmet was halted. The current Gen 2 helmet is expected to meet the requirements to declare, in July 2015, that the F-35 has obtained initial operational capability. Beginning in 2016 with low rate initial production (LRIP) lot 7, the program will introduce a Gen 3 helmet that features an improved night vision camera, new liquid crystal displays, automated alignment and other software enhancements.
In July 2015, an F-35 pilot commented that the helmet may have been one of the issues that the F-35 faced while dogfighting against an F-16 during a test; "The helmet was too large for the space inside the canopy to adequately see behind the aircraft. There were multiple occasions when the bandit would've been visible (not blocked by the seat) but the helmet prevented getting in a position to see him (behind the high side of the seat, around the inside of the seat, or high near the lift vector)".
Comments
Post a Comment