Saturday, June 28, 2008

United States Department of Defense - F-4 Phantom II


The McDonnell Douglas F-4 Phantom II is a two-seat, twin-engined, all-weather, long-range supersonic fighter-bomber originally developed for the U.S. Navy by McDonnell Aircraft.[2Proving highly adaptable, it became a major part of the air wings of the U.S. Navy, Marine Corps, and U.S. Air Force. It was used extensively by all three of these services during the Vietnam War, serving as the principal air superiority fighter for both the Navy and Air Force, as well as being important in the ground-attack and reconnaissance roles by the close of U.S. involvement in the war.

First entering service in 1960, the Phantom continued to form a major part of U.S. military air power throughout the 1970s and 1980s, being gradually replaced by more modern aircraft such as the F-15 Eagle and F-16 Fighting Falcon in the U.S. Air Force and the F-14 Tomcat and F/A-18 Hornet in the U.S. Navy. It remained in service in the reconnaissance and Wild Weasel roles in the 1991 Gulf War, finally leaving service in 1996.The Phantom was also operated by the armed forces of 11 other nations. Israeli Phantoms saw extensive combat in several Arab–Israeli conflicts, while Iran used its large fleet of Phantoms in the Iran–Iraq War. Phantoms remain in front line service with seven countries, and in use as an unmanned target in the U.S. Air Force.

Phantom production ran from 1958 to 1981, with a total of 5,195 built.This extensive run makes it the second most-produced Western jet fighter, behind the famous F-86 Sabre at just under 10,000 examples.
In 1952, McDonnell's Chief of Aerodynamics, Dave Lewis, was appointed by CEO Jim McDonnell to be the company’s Preliminary Design Manager. With no new aircraft competitions on the horizon, internal studies concluded the Navy had the greatest need for a new and different aircraft type, an attack fighter.

In 1953, McDonnell Aircraft began work on revising its F3H Demon naval fighter, seeking expanded capabilities and better performance. The company developed several projects including a variant powered by a Wright J67 engine, and variants powered by two Wright J65 engines, or two General Electric J79 engines. The J79-powered version promised a top speed of Mach 1.97. On 19 September 1953, McDonnell approached the United States Navy with a proposal for the "Super Demon". Uniquely, the aircraft was to be modular—it could be fitted with one- or two-seat noses for different missions, with different nose cones to accommodate radar, photo cameras, four 20 millimeter cannon, or 56 FFAR unguided rockets in addition to the nine hardpoints under the wings and the fuselage. The Navy was sufficiently interested to order a full-scale mock-up of the F3H-G/H but felt that the upcoming Grumman XF9F-9 and Vought XF8U-1 already satisfied the need for the supersonic fighter.

The McDonnell design was therefore reworked into an all-weather fighter-bomber with 11 external hardpoints for weapons and on 18 October 1954, the company received a letter of intent for two YAH-1 prototypes. On 26 May 1955, four Navy officers arrived at the McDonnell offices and, within an hour, presented the company with an entirely new set of requirements. Because the Navy already had the A-4 Skyhawk for ground attack and F-8 Crusader for dogfighting, the project now had to fulfill the need for an all-weather fleet defense interceptor. A second crewman was added to operate the powerful radar.

United States Department of Defense - A-6 Intruder


The A-6 Intruder is an American twin jet-engine, mid-wing attack aircraft built by Grumman Aerospace. In service between 1963 and 1997, the Intruder was designed as an all-weather replacement for the piston-engined A-1 Skyraider medium attack aircraft. A specialized electronic warfare derivative, the EA-6B Prowler, remains in service as of May 2008. As the A-6 was slated for retirement, its precision strike mission was taken over by the now retired F-14 Tomcat equipped with LANTIRN, which has subsequently passed on the role to the F/A-18E/F Super Hornet.
The Intruder was developed in response to a U.S. Navy specification for an all-weather carrier-based attack aircraft to serve as a replacement for the piston-powered, World War II-era A-1 Skyraider. Grumman was awarded the contract in 1957, and the resulting A2F-1 made its first flight on 19 April 1960.

The jet nozzles were originally designed to swivel downwards, but this was dropped from production aircraft. The pilot sits in the left seat, while the bombardier/ navigator sits to the right and below. A unique CRT gives a synthetic display of terrain ahead which, with the additional crew member, enabled low-level flying in all weather conditions.

The wing is very efficient at subsonic speeds compared to supersonic fighters such as the F-4 Phantom II, which are also limited to subsonic speeds when carrying a payload of bombs. A very similar wing would be put on pivots on Grumman's later supersonic swing-wing F-14 Tomcat, as well as similar landing gear. The Intruder was also equipped with the "Deceleron", a type of airbrake on the wings with two panels that open in opposite directions, in this case, one panel goes up, another goes down.

Thursday, April 10, 2008

United Kingdom Ministry of Defence - AgustaWestland EH101


The AgustaWestland EH101 (AW101 from June 2007) is a medium-lift helicopter for military applications but also marketed for civil use. The helicopter was developed as a joint venture between Westland Aircraft in the UK and Agusta in Italy (now merged as AgustaWestland). The name Merlin is used for EH101s in British and Portuguese military service.

The designation "EH101" is a typographical error that stuck: the aircraft was originally designated EHI (European Helicopter Industries) - 01. The aircraft is manufactured at the AgustaWestland factories in Yeovil, England and Vergiate in Italy.

The modular aluminium-lithium alloy fuselage structure is damage and crash resistant, with multiple primary and secondary load paths. Active vibration control of the structural response (ACSR) uses a vibration-cancelling technique to reduce the stress on the airframe. The EH101 is rated to operate in temperatures ranging from -40 to +50 °C. High flotation tyres permit operation from soft or rough terrain. The main rotor blades are a derivative of the BERP blade design, which improves the aerodynamic efficiency at the blade tips, as well as reducing the blade's noise signature.

The cockpit is fitted with armoured seats for the crew, and can withstand an impact velocity of over 10 m/s. Dual flight controls are provided, though the EH-101 can be flown by a single person. The pilot's instrument displays include six full colour high-definition screens and an optional mission display. A digital map and Forward-Looking Infrared system display can also be installed.

In spring 1977, the UK Ministry of Defence issued a requirement for an anti-submarine warfare (ASW) helicopter to replace the Royal Navy's Westland Sea Kings. Westland responded with a design designated the WG.34 that was then approved for development. Meanwhile, the Marina Militare (Italian Navy) was also seeking a replacement for its (Agusta-built) Sea Kings, leading Agusta to discussions with Westland about the possibility of a joint development. This culminated in the joint venture being finalised in November 1979 and a new company (EH Industries Limited [EHI], based in London) being formed in June the following year to manage the project.

As the design studies progressed, EHI became aware of a broader market for an aircraft with the same capabilities as those required by the British and Italian navies. On 12 June 1981, the UK confirmed their participation, with an initial budget of £20 billion to develop nine pre-series examples. At the 1985 Paris Air Show at Le Bourget, Agusta showed a mock-up of a utility version of the new helicopter, leading to a more generalised design that could be customised. After a lengthy development, the first prototype flew on October 9, 1987.

EHI was renamed AgustaWestland International Limited in January 2004 when parent companies merged. Consequently, in June 2007, the EH101 was re-branded as the AW101.

United Kingdom Ministry of Defence - BAE Hawk

The BAE Systems Hawk is a British advanced jet trainer which first flew in 1974 as the Hawker Siddeley Hawk. It is used by the Royal Air Force, and other air forces, as either a trainer or a low-cost combat aircraft. The Hawk is still in production with over 900 Hawks sold to 18 customers around the world.

n 1964 the Royal Air Force specified a requirement for a new initial jet trainer to replace the Folland Gnat. The SEPECAT Jaguar was originally intended for this role, but it was soon realised that it would be too complex an aircraft for initial jet training. Accordingly, in 1968 Hawker Siddeley began the design of a much simpler strictly subsonic trainer, the HS.1182. It was to have tandem seating and would be capable of carrying armaments, which would enable it to be used as a weapons trainer and in light combat roles.

Renamed "Hawk" in 1973, the aircraft first flew in 1974. It entered RAF service in April 1976, replacing the Gnat and Hawker Hunter in the advanced training and weapons training roles respectively. The following year Hawker Siddeley merged with other British aircraft companies to form the nationalised British Aerospace (BAe), which subsequently became BAE Systems upon merger with Marconi Electronic Systems in 1999.

The most famous RAF operator of the Hawk is the Red Arrows aerobatic team, which adopted the plane in 1979. The Finnish Air Force aerobatics team, the Midnight Hawks, also uses the aircraft.

The Hawk has excellent maneuverability, and while it is not capable of supersonic speed in level flight, it can attain Mach 1.2 in a dive, allowing trainees to experience trans-sonic handling without the cost of a supersonic trainer.

The Hawk subsequently replaced the English Electric Canberra in the target towing role.

The Royal Navy acquired a dozen Hawk T.Mk 1/1As from the RAF, for use as aerial targets for the training of ships gunners and radar operators.

United Kingdom Ministry of Defence - Westland WAH-64 Apache


The WAH-64 is a licence-built version of the Boeing AH-64D Apache Longbow attack helicopter, for the British Army. The first eight helicopters were built by Boeing, the remaining 59 were assembled by Westland at Yeovil from kits purchased from Boeing. The WAH-64 is designated Apache AH Mk 1 or AH1 by the UK's Ministry of Defence.

The UK's Strategic Defence Review called for Apaches to undertake amphibious attack missions, operating from the helicopter carrier HMS Ocean, the Invincible class aircraft carriers and their successors, the (Royal Navy CVF programme), and possibly the amphibious assault vessels HMS Bulwark and Albion. As such, one of the major differences between the WAH-64 and AH-64 Apache variants is the folding blade mechanism, required to stow the helicopters in the confined space onboard ships.

The Apache will serve aboard Royal Navy ships having achieved maritime certification in December 2005 aboard HMS Ocean. Then on November 17, 2006, HMS Ark Royal became the first RN aircraft carrier to land a WAH-64D Apache AH1 at Portsmouth Naval Base.

United Kingdom Ministry of Defence - Raytheon Sentinel


The Raytheon Sentinel is under development as the RAF's ASTOR (Airborne STand-Off Radar) aircraft. It will be a joint asset with the British Army, providing battlefield and ground surveillance in a similar role to the American E-8 JSTARS aircraft. ASTOR will be totally interoperable with allied systems such as JSTARS and the NATO Alliance Ground Surveillance (AGS) system.

The first flight of a modified Bombardier Global Express was in August 2001 which validated the modifications required for the ASTOR system. The first production Sentinel R1 made its 4.4 hour maiden flight on May 26 2004. The initial operating capability will be achieved in 2008.

The original contracts call for a total of five aircraft, eight mobile ground stations (six on wheeled all terrain vehicles and two in air transportable containers), and extensive training facilities at the main RAF station.

The ASTOR cockpit features a new centrally housed, pull-down screen capable of displaying a moving map, Link 16 datalink information and defensive aids subsystem (DASS) data.The DASS comprises a towed radar decoy, missile approach warning system and chaff and flare dispensers and can be operated in automatic, semi-automatic or manual mode.

The aircraft will normally fly at over 15,000 m (40,000 ft) to ensure a high resolution view of a large battlefield area. It will be crewed by a pilot, a co-pilot, an Airborne Mission Commander (AMC) and 2 image analysts. Mission endurance should be about 9 hours. While the image analysts can analyse the images on board the aircraft it is expected that, unlike the JSTARS, the actual battle management will occur on the ground.

The radar which provides this capability is supplied by Raytheon Systems Ltd. (RSL), the UK subsidiary of Raytheon. It is a next-generation dual-mode Synthetic Aperture / Moving Target Indication (SAR/MTI) radar based on proven technology previously used in Raytheon’s ASARS-2 system. The radar is installed on a heavily modified Bombardier business jet - the Global Express, which will be known as the Sentinel R1 in RAF service. The aircraft is powered by the same engines used in the Nimrod MRA4 upgrade programme, the Rolls-Royce BR710. The aircraft is based at RAF Waddington and operated by 5 Sqn.

The image to the right shows prototype 9001, a Global Express development aircraft belonging to Bombardier, carrying the external fairings and antennas of the radar and communications systems that will be fitted on the production aircraft. However it is substantially different in other areas, such as the number of portholes and military colours.

While suffering from delays the project is one of few procurement projects to be below cost estimates.

United Kingdom Ministry of Defence - Hawker Siddeley Nimrod


The Nimrod is a maritime patrol aircraft developed in the United Kingdom. It is an extensive modification of the de Havilland Comet, the world's first jet airliner. It was originally designed by de Havilland's successor, Hawker Siddeley, now part of BAE Systems. A major modification was the fit of a large weapon bay under the fuselage that can carry and drop torpedoes, mines, bombs and other stores. Sonobuoys for tracking submarines are dropped from special launchers in the rear of the fuselage.

It has been the Royal Air Force's primary Maritime Patrol Aircraft (MPA) since the early 1970s, when it replaced the piston-engined Avro Shackleton. The RAF uses two Nimrod variants: the MR2 variant in the Maritime and Reconnaissance role; the R1 variant in a reconnaissance and electronic intelligence gathering capacity (ELINT).

The Nimrod was the first jet-powered MPA of any significance. Earlier MPA designs used piston or turboprop engines to improve fuel economy and allow for lengthy patrols. Jet engines are most economical at high altitudes and less economical at low altitudes. However, the transit to the operational area can be made at high altitude and in a jet aircraft this is not only economical on fuel but fast as well, compared to earlier piston-powered aircraft. After transit, the Nimrod descends to its patrol area..