F-35 Joint Strike Fighter (Redirected from X-35)
The F-35 Joint Strike Fighter (JSF) is a joint venture between the USA and partner countries, principally the UK, to replace the current generation of strike fighters, particularly the VSTOL AV-8 Harrier II (US Model), the UK Sea Harrier and GR7/9 (UK models of the Harrier II), the A-10 Thunderbolt II, the F-18 Hornet and the F-16 Fighting Falcon. It is to be a multirole strike fighter (a plane with a strong emphasis on close air support and tactical bombing as well as air-to-air combat) currently in early development by Lockheed Martin with partners Northrop Grumman and BAE Systems.
Three JSF variants are envisioned: the conventional take-off and landing (CTOL) F-35A for the U.S. Air Force (USAF) and the RAF; the Advanced Short Take-Off Vertical Landing (ASTOVL) F-35B for the US Marine Corps (USMC) and the Royal Navy (RN); and the carrier-based (CV) F-35C for the U.S. Navy (USN). The USAF is considering the F-35B. The Royal Navy is considering ordering the F-35C variant for its large CVF Future Carrier program.
Reportedly, export versions for some countries other than the UK may be subject to some restrictions and carry different mission systems. What equipment would be changed, and the difference in capabilities is not known.
The primary customers are the United States armed forces (USAF, USN, and USMC) and the United Kingdom (RAF and RN). There are five levels of international participation for the 10 participants in the program. Level I consists of the United States, Level II consists of the United Kingdom, Level III consists of Italy and the Netherlands, and Level IV consists of Canada, Turkey, Australia, Denmark, and Norway. The levels indicate financial stake in the program (about $2b, $1b, and $150m for Levels II, III, and IV, respectively) and level of technology transfer and subcontracts to national companies. Israel and Singapore have joined as Security Cooperative Participants.[1] (http://www.jsf.mil/program/prog_intl.htm)
Israeli involvement in the project was temporarily suspended in April 2005 due to a dispute with the United States over the now-cancelled upgrades to Harpy UAVs sold to China. With the UAV dispute resolved, as of October 2005 Israel has been re-admitted to the programme [2] (http://www.haaretz.com/hasen/spages/634298.html).
The Joint Strike Fighter was scheduled to replace the A-10 Thunderbolt II in the USAF in 2008 (but the USAF opted to keep the A10 in service till 2028). It is also supposed to begin replacing the Marine Corps AV-8B Harrier in 2008.
Specifications (F-35 Joint Strike Fighter)
The F-35 Joint Strike Fighter Some information is estimated.
General characteristics
- Crew: One
- Length: 50 ft 6 in (15.37 m)
- Wingspan: 35 ft 0 in (10.65 m)
- Height: 17 ft 4 in (5.28 m)
- Wing area: 459.6 ft² (42.7 m²)
- Empty: 26,455 lb (12,000 kg)
- Loaded: 41,900 lb (19,000 kg)
- Maximum takeoff: 50,000 lb (22,680 kg)
- Powerplant:
Performance
- Maximum speed: 2000 km/h (??? mph) Mach 1.8
- Range: 620 miles (1000 km) without drop tanks
- Service ceiling: 48,000 ft (15,000 m)
- Rate of climb: m/min ( ft/min)
- Wing loading: 91.4 lb/ft² (446 kg/m²)
- Thrust/weight: 6.2 N/kg
Armament
- 1x GAU-12/U 25 mm cannon (internal with 180 rounds in F-35A, as an external pod with 220 rounds in F-35B/C)
- In two bomb bays(current planned weapons for intergration) - One AIM-120 AMRAAM, AIM-9X Sidewinder or AIM-132 ASRAAM internally on the missile spot on the inside of the bomb bay door and one Air to Air or Air to Ground weapon in each bomb bay. These may include AMRAAM(single racks only planned at this stage), Joint Direct Attach Munitions(JDAM of up to 2000lb class), Joint Stand off Weapon(JSOW), Small Diameter Bombs(SDB)(up to 4 in each bay), Brimstone anti-armour missiles, Cluster Muntions with the Wind Controlled Munitions Dispenser(WCMD) and High Speed Anti-Radiation Missiles(HARM). The Meteor Air to Air missile is currently being adapted to fit internally in the missile spots and may be intergrated into the F-35.
- At the expense of stealth, several more stores (missiles/bombs/external fuel tanks) can be attached to the aircraft via four external pylons and two wingtip positions on the wings. The wingtip positions are only for short-range air to air missiles(ASRAAM or Sidewinder, while the Storm Shadow and Joint Air to Surface Stand-off Missile(JASSM) cruise missiles can be carried in addition to the stores already integrated.
Other
- Cost: (in millions US$):
- F-35A: 45
- F-35B: 55
- Costings as per Asia Pacific Defence Reporter, September 2005.
- F-35C: Current costings unavailable, but based on previous costings these versions will be more expensive than the F-35A.
- First flight - X-35 demonstrator: 2000
- Expected first flight F-35A - 2006
- In-service date: expected to be 2008 through 2011
Design
Design requirements for the JSF include:
- Stealth technology
- Integrated avionics and sensor fusion - This allows information from offboard sensors to be combined with those on-board the aircraft, to enhance the pilot's situational awareness and improve precision weapon delivery.
- Low construction cost
- Low maintenance cost
Manufacturing responsibilities
- BAE Systems
- Aft fuselage and empennages
- Horizontal and vertical tails
- Crew life support and escape
- Electronic warfare systems
- Fuel system
- Flight Control Software (FCS1)
Program history
Boeing X-32 (left) and Lockheed Martin X-35 prior to down-select in 2001, where the X-35 was chosen. DoD photo The Joint Advanced Strike Technology (JAST) program was created in 1993 as a result of a United States Department of Defense (DoD) Bottom-Up-Review. The major tactical aviation results of the review were to continue the ongoing F-22 and F/A-18E/F programs, cancel the Multi-Role Fighter (MRF) and the A/F-X programs, curtail F-16 and F/A-18C/D procurement, and initiate the JAST Program.
The JAST program office was established on January 27, 1994. It was established to define and develop aircraft, weapon, and sensor technology that would support the future development of tactical aircraft. The final goal was a common family of aircraft to replace several aging US and UK aircraft of which the JSF is one such example.
The JSF is a multi-role attack and fighter aircraft designed to replace the aging F-16 Fighting Falcon, F/A-18 Hornet, A-10 Thunderbolt II, F-111 Aardvark, Sea Harrier, Harrier GR7/GR9, and AV-8B Harrier jets. It will complement the USAF's high-end F/A-22 Raptor air superiority fighter and the USN's F/A-18E/F Super Hornet as well as Europe's Eurofighter.
Concept Demonstration
The contract for development of the prototypes was awarded on 16 November 1996 to Lockheed Martin and Boeing, under which each was to produce two aircraft which were to demonstrate Conventional Take Off and Landing (CTOL), carrier take off and landing (CV version), and Short Take Off and Vertical Landing (STOVL).
Also in 1996 the UK Ministry of Defence launched the Future Carrier Borne Aircraft project, a replacement for the Sea Harrier (and later the Harrier GR7), for which the Joint Strike Fighter was selected in January 2001.
System Development and Demonstration
The construction contract, System Development and Demonstration (SDD), was awarded on 26 October, 2001 to the Lockheed Martin X-35, beating the Boeing X-32. The first planes are expected to enter service in 2008. Announcing the decision, DoD officials and the UK Minister of Defence Procurement said that while both aircraft met or exceeded requirements, the X-35 outperformed the Boeing aircraft consistently. This dominance can only have been achieved by Lockheed's method of STOVL flight, in fact the decision is said to have clinched the contract. While Boeing adopted the direct lift system, as in the Harrier, the X-35 generates vertical thrust through the use of the Rolls Royce LiftFan and a thrust-vectoring exhaust nozzle. The LiftFan alone generates 18,000 lbf (80 kN) of thrust, compared to the 21,500 lbf (96 kN) thrust of the Harrier's Pegasus engine. This method has the additional benefit of lowering environmental effects during (primarily) landing, where the thermal effects on for example a carrier deck are greatly reduced. Boeing's direct lift fan made it necessary to create a huge front air intake, compromising the aesthetics of the aircraft's aerodynamics. According to critics, Boeing designed an airplane "only its mother would love", in direct violation of the wisdom "if it looks good, it flies good". To make matters worse, Boeing had to strip parts of the plane prior to the vertical landing and take-off demonstrations to reduce weight, like the front air intake mouth and several other panels.
Analysis of JSF program
Critics of the program maintain that the JSF suffers from ill-defined design goals; that it has insufficient internal fuel and weapon capacity to make a capable replacement for dedicated bombing aircraft; that its inability to supercruise limits it as an air defence platform, and that it is almost certain to suffer lengthy development delays and cost over-runs — meaning that interim types will have to be purchased to fill the gap between the end of useful life of existing fleets and the introduction of the JSF. However, it is important to note that the multi-role design philosphy has been tested and proven in combat over a period of at least 25 years, with successful types like the F-16 Fighting Falcon and the F-18 Hornet. Several nations, mainly current F-16 and F-18 users, already have sufficient confidence in the design to have committed substantial sums to become minority partners in the JSF manufacturing team.
The program's advocates see the JSF as an opportunity to break out of the decades-old pattern of US military aircraft procurement: instead of a traditional per-service design approach, the JSF is being developed jointly by the Air Force, Navy and Marine Corps. This allows an estimated 80% commonality between the JSF variants for the different services, lowering procurement and service costs. This follows to a degree the philosophy behind the SEPECAT Jaguar and Panavia Tornado international development programs, the latter being called a multi-role combat aircraft (or MRCA) prior to service entry. Additionally, JSF is the first US aircraft program to consider cost as independent variable (CAIV). In earlier programs, the aircraft cost has been a dependent variable — additional features have always increased the aircraft cost. Such design changes aren't being allowed during the JSF development.
Cost/weight issues
In 2004, it emerged that the JSF was suffering development delays and cost blowouts, with the total projected cost of the program rising 23 percent to $244 billion. The major technical problem was the STOVL F-35B variant's mass, which was reported to be 8 percent over the target level (over 2200 pounds), which meant that the plane was projected as not being able to meet performance requirements. The Air Force CTOL F-35A variant and the Navy F-35C carrier-based variant were both within weight limits.
Lockheed Martin eventually solved the weight issues (http://www.aviationnow.com/avnow/news/channel_awst_story.jsp?id=news/09204wna.xml), shedding over a ton, and adding engine thrust. Several steps were taken to achieve this weight reduction, including reducing the thickness of the aircraft's skin, reducing the size of the weapons bay and vertical tails, redesigning the wing-mate joint, portions of the electrical system, and the portion of the aircraft immediately behind the cockpit, and lastly, rerouting some thrust from the roll-post outlets to the main nozzle.
The smaller weapons bay will mean that the F-35B cannot carry Mark 84 2,000 lb (900 kg) bombs internally(now being limited to 2 x 1000lb weapons), but this is typically not necessary in the envisioned close air support role. This is especially the case given that most close-air support missions are likely to involve the aircraft using external weapons, once enemy air-defences have been suppressed. The combined external weapons load of the F-35B is comparable to the aircraft it will replace and should be more than adequate for the close air support mission. It should also be noted that the original plans for the F-35B were for a 2 x 1000lb internal weapon capacity, with the 2 x 2000lb plan being added later in the program. As such, the modifications don't represent a change from the original goals for the F-35B.
Also of growing concern is the 'canted' carriage of stores in the internal weapons bays - that is, the bombs/stores are carried with a directional cant at an angle to the free stream air flow. This will make for some interesting weapons certification work. The JSF has yet to drop a bomb, fire a missile, or fire a gun airborne - no demonstrations of weapons delivery capability were done during the 'winner take all' fly off prior to contract award.
USAF STOVL purchase
One important development has been the emergence of the USAF requirement for the F-35B. The STOVL variant had been viewed as the most likely victim of cost-cutting measures, however the USAF commitment seems to guarantee the aircraft that the USMC, RN, and RAF need. It is understood that the US military's experience in Afghanistan has highlighted the importance of more flexible assets in the close air support role.
USAF has elected to buy three wings (representing 216 examples) of the F-35B, as a result. For a time, it appeared that the USAF variant of the F-35B would contain enough changes to constitute a new variant. Changes were to include differences in the propulsion system to increase emphasis on STOL capability over that of VTOL, a larger wing to allow more fuel, an interior cannon (as opposed to the USMC external gun pod), or changes to the in-flight refuelling system. However, due to opposition from people involved with the program, the USAF version will be essentially identical to the USMC/RN F-35B specification.
International participation
Some of the international partners in the project have also become somewhat skittish, with Norway reportedly considering switching their purchase to the Eurofighter Typhoon or Saab Gripen because Norwegian industry had not been offered enough work.
The biggest international partner, the United Kingdom, has also become somewhat discontented. The CEO of BAE Systems, the British contractor on the plane, has complained that the US has not given the UK (and his company) access to the crucial source code of the plane's software, thus making it impossible for Britain to maintain and modify the JSF independently. At a news conference at the Paris Air Show, he has even suggested that Britain may withdraw from the program unless additional access is granted, though analysts consider this unlikely [3] (http://www.bloomberg.com/apps/news?pid=10001062&sid=a_DiEG3P6thw&refer=movers_by_index).
The Australian government and defense establishment has remained solidly behind the project; however, in May 2005 the government did announce that it was delaying a final decision on the JSF from the initial 2006 decision date to 2008 (and thus past the term of the present government). The media release also noted some preliminary consideration was being given to changing some of the purchase to the STOVL version, as well as modifying some Navy landing craft to in effect turn them into mini aircraft carriers. However, there are some concerns amongst Australian media, lobby groups and politicians, who have have raised doubts that the aircraft will be ready in time to replace the aging Australian air force fleet of F-111 ground attack planes and F-18 fighters.
Some Australian observers have criticized the planned purchase on the basis of its capabilities and value for money. They believe that, given the increasing sophistication of neighboring air forces, it may have inadequate dogfighting capability, a short range and are concerned that it is not able to supercruise like the F-22, thus limiting the number of sorties it can conduct compared to that aircraft. They also claim that the cost of purchasing mature F-22's (after the US government has purchased its quota and thus any additional sales are "money for jam" for the manufacturers) may not be that much greater than the JSF. As such they question whether it will be suitable to replace both the F-18 and F-111, particularly if it does not fully meet its design goals. (Refer related discussions and analyses on Air Power Australia web site (http://www.ausairpower.net)).
It should be noted on this claim that Janes Defence weekly recently (in 2005) put the value of an F-22 at $151 million dollars US, rising to $200 million if upgrades to approach the F-35's air to ground targeting performance were included. At a projected price of $45 million US (2003 dollars), the F-35 is three to four times cheaper than the F-22. Therefore, there would have to be a very significant cost blowout in the F-35 program for the F-22 to become better value for money.
What also needs to be considered, is that the F-22 has an even smaller internal weapons capacity to the F-35A, with 2 x 1000lb weapons versus the F-35A's 2 x 2000lb weapons. In addition to this, no plans have been announced in the US to intergrate the wide range of weapons available on the F-35 onto the F-22, meaning Australia would have to assume the cost and technological risk of doing so.
Also, the claims made by Australian observer Carlo Kopp (see the above reference) that supercruise will dramatically increase the sortie rate of the F-22, fail to consider the fact that higher speed is only one variable impacting on sortie rate. Maintainability (a particular emphasis in the newer F-35 design), the time needed to re-arm and refuel, loiter time over the combat area and the need to brief and rest crew are other important variables. Additionally where external stores are carried (which will probably be the vast majority of air to ground missions), the F-22 will not be able to supercruise for at least half the mission. Finally, at least one retired US airforce officer has claimed that the supercruise feature is overrated as a means of traversing long distances at high speed, as flying at supersonic speed without using afterburners still does not allow for optimal fuel consumption, hence range.
Additionally, in a recent paper to the Australian Strategic Policy Institute, in his role as the Chief of the Australian Air Force, Air Marshall Angus Houston (now Chief of the Defence Force), sought to allay these concerns. He maintains that he is quietly confident that the aircraft will have adequate range, especially when combined with the RAAF's new Airbus A330 MRTT air to air refueling tankers. He also stated that he believes that the aircraft will have adequate maneuverability to avoid missiles, which is all it will require. With modern air combat being conducted mainly at beyond visual ranges and with short-range missiles that can be aimed by a sight mounted on the pilot's helmet in those instances that an aircraft has to fight within-visual ranges, he believes that the exceptional maneuverability of aircraft like the F-22 is no longer necessary. The Australian Government also argues that the RAAF's new AEW&C aircraft (Boeing Wedgetail) will increase the capabilies of the JSF beyond that of any other potentialy hostile aircraft. It is worth noting that the debate on the importance of maneuverability goes well beyond Australia — see the article on Comparison of 21st century fighter aircraft. Finally, he said that the level of stealth that the Australian aircraft will receive is classified, but is being monitored by a team of Defense Science and Technology Organization scientists and that all efforts will be made to ensure that the aircraft has adequate capability for Australia, prior to the final purchase agreement.
Further reading
External links
Related content
Related development:
Comparable aircraft: Eurofighter Typhoon - Dassault Rafale
Designation Series:
F-21 -
F/A-22 -
YF-23 -
F-35
X-32 -
X-33 -
X-34 -
X-35 -
X-36 -
X-37 -
X-38
See also:
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