F-35 Joint Strike Fighter
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The F-35 Joint Strike Fighter (JSF) is a military fighter aircraft
designed by the USA and the United Kingdom. It is intended to
replace the current generation of strike fighters, particularly the
vertical take off and landing Harrier jump jets : the AV-8 Harrier
II (US), Harrier GR7/9 (UK), and the Sea Harrier (UK), along with
the conventional A-10 Thunderbolt II, F/A-18 Hornet and the F-16
Fighting Falcon. It is set to be a multi-role strike fighter (a
plane with a strong emphasis on close air support and tactical
bombing as well as being capable of air-to-air combat), currently
in production with Lockheed Martin, along with partners Northrop
Grumman and BAE Systems.
Three variants are envisioned: the conventional takeoff 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
U.S. 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, and the Royal Navy is considering ordering
the F-35C variant for its large CVF Future Carrier programme.
The F-35, expected to be ready for service in 2008, is scheduled to
begin replacing Marine Corps AV-8B Harrier and F/A-18s in 2009, and
the USAF A-10 Thunderbolt II and F-16 in 2010.
International participation
F-35 lift fan; the VTOL propulsion system is designed and
manufactured by Rolls-Royce plc.
Enlarge
F-35 lift fan; the VTOL propulsion system is designed and
manufactured by Rolls-Royce plc.
The primary customers are the armed forces of the United States
(USAF, USN, and USMC) and the United Kingdom (RAF and RN). There
are three levels of international participation for the eight
countries contributing to the program. The United Kingdom is the
sole level I partner, contributing a little over $2 billion. Level
II partners are Italy and the Netherlands, contributing $1 billion
and $800 million respectively. At level III are Turkey ($175
million), Australia ($144 million), Norway ($122 million), Denmark
($110 million), and Canada ($100 million). The levels generally
indicate the financial stake in the program, the level of
technology transfer and subcontracts open for bid by national
companies, and the general order in which countries can obtain
production aircraft. Israel and Singapore have also joined as
Security Cooperative Participants. [1]
The biggest international partner, the United Kingdom, has invested
two billion in development funding for the project. Britain has
also worked for five years for an ITAR waiver to allow greater
technology transfer associated with the project. The effort, backed
by the Bush administration, has been repeatedly blocked by U.S.
Congressman Henry Hyde because of his concern about potential
technology transfer to third countries. [2]
The CEO of BAE Systems, the British contractor on the plane, has
complained that the U.S. has not given the UK (and his company)
access to the crucial source code of the plane's software, thus
making it impossible for the UK to maintain and modify the JSF
independently. At a news conference at the Paris Air Show, he has
even suggested that the UK may withdraw from the program unless
additional access is granted, though analysts consider this
unlikely [3]. On 21 December 2005 an article was published in the
Glasgow Herald saying that MPs viewed as "unacceptable" the U.S.
refusal to grant access to the source code. The article quotes the
chairman of the Commons Defence Select Committee as saying that
unless the UK receives assurances of access to the software
information, "the UK might have to consider whether to continue in
the programme".[4] Nonetheless, UK production commenced on 2
February 2006.[5]
International participants have at various times been cited as
considering withdrawing from the JSF Program in favor of other
aircraft such as Eurofighter Typhoon, Gripen or Rafale. Perceived
inequitable sharing in JSF production is most often cited as the
reason for considering withdrawal, rather than cost or performance
concerns.
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
Enlarge
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 to replace several aging U.S. and UK
aircraft with a common family of aircraft, of which the JSF is one
example.
It will complement the USAF's high-end F-22 Raptor air superiority
fighter and the USN's F/A-18E/F Super Hornet as well as Europe's
Eurofighter.
[edit]
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.
[edit]
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.
On February 19, 2006, the first F-35 (USAF version) was rolled out
in Fort Worth, Texas by Lockheed Martin. The aircraft will undergo
extensive ground testing and then flight tests in the fall.
Design
The Harrier, which the JSF is set to replace.
Enlarge
The Harrier, which the JSF is set to replace.
The X-35 powerplant uses the highly complex Remote Shaft-Driven
Lift Fan concept, where (in the STOVL mode) LP turbine power is
diverted, forward via a clutch-and-bevel gearbox, to a vertically
mounted, contra-rotating, remote fan. Bypass air exhausts through a
pair of roll post nozzles on either side of the fuselage, whilst
both the remote fan and the LP turbine streams exhaust through
thrust vectoring nozzles. In effect, the X-35 power plant acts as a
flow multiplier and consequently has more than sufficient thrust
for lift operations. This lift concept has the additional benefit
of lowering environmental effects during (primarily) landing, where
the thermal effects on, for example, a carrier deck are greatly
reduced.
The rival Boeing X-32 adopted the relatively elegant Direct Lift
System, where the engine exhaust gases were redirected to thrust
vectoring nozzles to achieve lift during a STOVL landing. However,
even though the fan was oversized and throttle-pushed, it had
insufficient thrust for lift. Because of the large engine airflow,
the X-32 required 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 maxim "if it looks good, it flies good".
Both the X-32 and X-35 power plants were derived from Pratt &
Whitney F119, with the STOVL variant of the latter incorporating
Rolls Royce Lift Fan module.
Note also that elements of the JSF design were pioneered by the
F-22. The airframe appears quite similar to the F-22, albeit
somewhat reduced in size, and only has a single engine.
Primary factors in the design included:
* Stealth technology capability
* Integrated avionics and sensor fusion - This allows information
from off board 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
[edit]
Advanced weapons
The direct lift fan assembly, when not installed, provides
approximately 100 ft3 of space [6], along with more than 27,000 hp
(20 MW) available for electrical power production [7]. This has
made directed-energy weapons possible for the F-35. Some of these
designs, including solid state lasers and high-power microwave
beams, are thought to be nearing operational status [8].
[edit]
Possible reduction to two primary variants
Experts predicted in 2005 that the JSF program's Conventional
Take-off and Landing [CTOL] F-35A variant may be canceled by acting
U.S. Deputy Defense Secretary Gordon England. [9] This would not
immediately save money in the program as the preproduction F-35A
prototypes are already under construction, but long term, this
cancellation could free up enough money to ensure that the
program's F-35B and F-35C variants survive in the United States'
tightening defense budget. Since then a flurry of lobbying from the
JSF contractors, the Air Force, and representatives from the United
Kingdom has convinced Secretary England and the DoD to stick with
the 3-variant program.
Had such a cancellation occurred, the United States Air Force would
stay in the program by purchasing either the STOVL F-35B for its
close air support capabilities, the F-35C for its greater range, or
a combination of the two. However, buys of these variants would
likely be less than the 1000+ CTOL originally envisioned by the Air
Force, as both variants cost more. This would have been a boon for
A-10 and F-16 supporters, since those aircraft would probably be
retained longer to compensate.
Export partners who were already wary of the JSF's rising costs
showed some concern over a potential CTOL cancellation. Even the
UK, which has no CTOL JSF requirement, lobbied to preserve that
variant in order to keep costs of the others down. In the long run,
the F-35B and F-35C should still be appealing to at least some of
the international market, being the only fifth-generation program
with a STOVL variant for countries in need of Harrier
replacements.
[edit]
Analysis of JSF program
Critics of the program maintain that the JSF suffers from
ill-defined design goals; that it has insufficient range to make a
capable replacement for dedicated bombing aircraft; that its
inability to supercruise limits it as an air defense platform, and
that it is almost certain to suffer lengthy development delays and
cost overruns; 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 philosophy 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 U.S. 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 U.S. 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 are not being allowed during the JSF
development.
[edit]
Non-vehicle differentiator
A ground-based information system (the Autonomic Logistic
Information System, or ALIS), built by Lockheed Martin Simulation
Training and Support, is intended to make the JSF less expensive to
operate and maintain.
[edit]
Cost/weight issues
Through 2004 the JSF's total projected cost had risen 23% to $244
billion. The major technical problem was the F-35B variant's mass,
which was reported to be 2,200 pounds, or 8%, over the target,
which meant that the STOVL plane was projected to miss performance
requirements.
Lockheed Martin eventually solved the weight problem by adding
engine thrust and shedding over a ton by thinning the aircraft's
skin; shrinking the F-35B 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
rerouting some thrust from the roll-post outlets to the main
nozzle. [10]
The smaller weapons bay will limit F-35B to 2 x 1000 lb (450 kg)
weapons internally (this is as originally planned, for the 2 x 2000
lb requirement was added later). This is not expected to be a
hindrance in close air support missions, which are likely to take
place after enemy air defenses are down. Still, this may make the B
variant different from the other two, boosting costs.
The internal weapons are stored offline to the external air flow,
which 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.
[edit]
USAF STOVL purchase
The JSF program is not immune from interservice politics. A
recurring theme has been the potential for a USAF requirement for
the F-35B. The STOVL variant had been viewed as the most likely
victim of cost-cutting measures; however, a USAF "commitment" seems
to guarantee the aircraft that the USMC, RN, and RAF need. It is
understood that the U.S. military's experience in Afghanistan has
highlighted the importance of more flexible assets in the close air
support role.
The USAF has investigated buying up to three wings (representing
216 examples) of the F-35B. For a time it appeared that the
hypothetical USAF variant of the F-35B would contain enough changes
to constitute a new variant (an F-35D). 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 refueling system. However, due to
opposition from people involved with the program, and the
associated cost of developing a fourth variant, the USAF version
would likely be identical to the USMC/RN F-35B specification.
[edit]
Australian Participation
In May 2005 the Australian government announced 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).
There are some concerns amongst Australian media, lobby groups and
politicians, who 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/A-18 fighters.
Concerns have been raised over cost efficiency, dog fighting
capability, short range and lack of supercruise. The government
also claims that the cost of purchasing mature F-22s may not be
that much greater than the JSF. [11]
It should be noted on this claim that Jane’s Defence weekly
recently (in 2005) put the value of an F-22 at $151 million dollars
U.S., 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 U.S. (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.
[edit]
Specifications (F-35 Joint Strike Fighter)
The F-35 Joint Strike Fighter
Enlarge
The F-35 Joint Strike Fighter
Some information is estimated.
General characteristics
* Crew: 1
* 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 weight: 26,000 lb (12,000 kg)
* Loaded weight: 42,000 lb (19,000 kg)
* Maximum gross takeoff weight: 50,000 lb (23,000 kg)
* Powerplant: 1× Pratt & Whitney F135 afterburning turbofan,
37,100 lbf (165 kN)
o Secondary (High Performance), discontinued in current budget
proposal[12]: 1x General Electric/Rolls-Royce F136 afterburning
turbofan 178 kN thrust
o Lift fan (STOVL): 1x Rolls-Royce Lift System in conjunction with
either F135 or F136 power plant 18,000 lbf (80 kN) thrust)
each
Performance
* Maximum speed: Mach 1.8 (1,200 mph, 2,000 km/h)
* Cruise speed: Mach (mph, km/h)
* Range: 620 miles (1,000 km)
* Service ceiling: 48,000 ft (15,000 m)
* Climb rate: 40,000 ft/min[13] (200 m/s)
* Wing loading: 91.4 lb/ft² (446 kg/m²)
* Thrust/weight: 0.63:1
Armament
* 1x GAU-12/U 25 mm cannon. Mounted internally with 180 rounds in
the F-35A, fitted as an external pod with 220 rounds in the
F-35B/C
* In two bomb bays (current planned weapons for integration) - One
AIM-120 AMRAAM, AIM-9X Sidewinder or AIM-132 ASRAAM internally on
the inside of the bomb bay door and one air-to-air or air-to-ground
weapon in each bomb bay. These could be AMRAAM, the Joint Direct
Attack Munitions (JDAM) - up to 2,000 lb (910 kg), the Joint Stand
off Weapon (JSOW), Small Diameter Bombs (SDB)- a maximum of 4 in
each bay, the Brimstone anti-armor missiles, Cluster Munitions
(WCMD) and High Speed Anti-Radiation Missiles (HARM). The MBDA
Meteor air to air missile is currently being adapted to fit
internally in the missile spots and may be integrated into the
F-35.
* At the expense of being more detectable by radar, more missiles,
bombs and fuel tanks can be attached on four wing pylons and two
wingtip positions. The latter can only take short-range air-to-air
missiles, 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.
[edit]
Other
* Cost: (in millions US$):
o F-35A: 45
o F-35B: 60
o Costing as per Asia Pacific Defence Reporter, September
2005.
o F-35C: 55
* First flight - X-35 demonstrator: 2000
* Expected first flight F-35A - September 2006
* In-service date: expected to be 2009 through 2012. The reason for
this is that the A will be brought into service first followed by
the B. The C will be in service in 2012.
[edit]
Manufacturing responsibilities
* Lockheed Martin Aeronautics (prime contractor)
o Final assembly
o Overall system integration
o Mission system
o Forward fuselage
o Wings
* Northrop Grumman
o Active Electronically Scanned Array (AESA) radar
o Center fuselage
o Weapons bay
o Arrestor gear
* BAE Systems
o Aft fuselage and empennages
o Horizontal and vertical tails
o Crew life support and escape
o Electronic warfare systems
o Fuel system
o Flight Control Software (FCS1)
http://en.wikipedia.org/wiki/F-35_Joint_Strike_Fighter
