Posted tagged ‘cannon’

Whispering Thunder

September 12, 2010

Fairchild Republic A-10 Thunderbolt II

 The A-10 Thunderbolt II is an American single-seat, twin-engine, straight-wing jet aircraft developed by Fairchild-Republic in the early 1970s. The A-10 was designed for a United States Air Force requirement to provide close air support for ground forces by attacking tanks, armored vehicles, and other ground targets with a limited air interdiction capability. It is the first U.S. Air Force aircraft designed exclusively for close air support.

The A-10 was designed around the GAU-8  Avenger ,  a  heavy automatic cannon which forms the aircraft’s primary armament. The aircraft’s hull incorporates over 1,200 pounds of armor and was designed with survivability as a priority, with protective measures in place which enable the aircraft to continue flying even after taking significant damage.

The A-10’s official name comes from the Republic P-47 Thunderbolt of World War II, a fighter that was particularly effective at close air support. The A-10 is more commonly known by its nickname “Warthog” or simply “Hog”. As a secondary mission, it provides airborne forward air control, guiding other aircraft against ground targets. A-10s used primarily in this role are designated OA-10.The A-10 is expected to be replaced in 2028 or later.

 Development

 Background

Criticism that the U.S. Air Force did not take close air support seriously prompted a few service members to seek a specialized attack aircraft. In the Vietnam War, large numbers of ground-attack aircraft were shot down by small arms, surface-to-air missiles, and low-level anti-aircraft gunfire, prompting the development of an aircraft better able to survive such weapons. In addition, the UH-1 Iroquois and AH-1 Cobra helicopters of the day, which USAF commanders had said should handle close air support, were ill-suited for use against armor, carrying only anti-personnel machine guns and unguided rockets meant for soft targets. Fast jets such as the F-100 Super Sabre, F-105 Thunderchief and F-4 Phantom II proved for the most part to be ineffective for close air support. The A-1 Skyraider was the USAF’s primary close air support aircraft.

A-X

In mid-1966 the U.S. Air Force formed the Attack Experimental program office. On 6 March 1967, the Air Force released a request for information to 21 defense contractors for the A-X. The objective was to create a design study for a low-cost attack aircraft. The officer in charge of the project was Colonel Avery Kay. In 1969, the Secretary of the Air Force asked Pierre Sprey to write the detailed specifications for the proposed A-X project. However, his initial involvement was kept secret due to Sprey’s earlier controversial involvement in the F-X project. Sprey’s discussions with A-1 Skyraider pilots operating in Vietnam and analysis of the effectiveness of current aircraft used in the role indicated the ideal aircraft should have long loiter time, low-speed maneuverability, massive cannon firepower, and extreme survivability; an aircraft that had the best elements of the Ilyushin Il-2, Henschel Hs 129 and Skyraider. The specifications also demanded that the aircraft cost less than $3 million. Input on the design was later provided by famed World War II attack pilot Hans-Ulrich Rudel.

In May 1970, the USAF issued a modified, and much more detailed request for proposals . The threat of Soviet armored forces and all-weather attack operations had became more serious. Now included in the requirements was that the aircraft would be designed specifically for the 30 mm cannon. The RFP also called for an aircraft with a maximum speed of 460 mph , takeoff distance of 4,000 feet , external load of 16,000 pounds , 285-mile mission radius, and a unit cost of US$1.4 million. During this time, an RFP was released for A-X’s 30 mm cannon with requirements for a high rate of fire (4,000 round/minute) and a high muzzle velocity.Six companies submitted proposals to the USAF, with Northrop and Fairchild Republic selected to build prototypes: the YA-9A and YA-10A, respectively. General Electric and Philco-Ford were selected to build and test GAU-8 cannon prototypes.The YA-10A first flew on 10 May 1972. After trials and a fly-off against the YA-9A, the Air Force announced its selection of Fairchild-Republic’s YA-10A on 18 January 1973 for production. General Electric was selected to build the GAU-8 cannon in June 1973. The YA-10 had an additional fly-off in 1974 against the Ling-Temco-Vought A-7D Corsair II, the principal Air Force attack aircraft at the time, in order to prove the need to purchase a new attack aircraft. The first production A-10 flew in October 1975, and deliveries to the Air Force commenced in March 1976 to units at Davis-Monthan Air Force Base, Arizona. The first squadron to use the A-10 went operational in October 1977. In total, 715 airplanes were produced, the last delivered in 1984.One experimental two-seat A-10 Night Adverse Weather version was built by converting an A-10A. The N/AW was developed by Fairchild from the first Demonstration Testing and Evaluation A-10 for consideration by the USAF. It included a second seat for a weapons system officer responsible for electronic countermeasures , navigation and target acquisition. The variant was canceled and the only two-seat A-10 built now sits at Edwards Air Force Base awaiting a spot in the Flight Test Historical Foundation museum. The N/AW version did not interest the USAF or export customers. The two-seat trainer version was ordered by the Air Force in 1981 but funding was canceled by Congress and was not produced.

Upgrades

The A-10 has received many upgrades over the years. Aircraft added the Pave Penny laser receiver pod beginning in 1978. It senses reflected laser radiation from a laser designator on a target for faster and more accurate target identification. The A-10 began receiving an inertial navigation system in 1980. Later, the Low-Altitude Safety and Targeting Enhancement upgrade provided computerized weapon-aiming equipment, an autopilot, and a ground-collision warning system. The A-10 is now compatible with night vision goggles for low-light operation. In 1999, aircraft began to receive Global Positioning System navigation systems and a new multi-function display. Its LASTE system is being upgraded with the Integrated Flight & Fire Control Computers .

In 2005, the entire A-10 fleet also began receiving the Precision Engagement upgrades that include an improved fire control system , electronic countermeasures, and the ability to aim smart bombs. The aircraft that receive this upgrade are redesignated A-10C. The A-10 will receive a service life extension program  upgrade with many receiving new wings. A contract to build 242 new A-10 wing sets was awarded to Boeing in June 2007. In July 2010, the USAF issued Raytheon a contract to integrate a Helmet Mounted Integrated Targeting system into A-10Cs.

The Government Accounting Office in 2007 estimated the cost of upgrading, refurbishing, and service life extension plans for the A-10 force to total $2.25 billion through 2013. Modifications to provide precision weapons capability are well underway. The Air Force Material Command’s Ogden Air Logistics Center at Hill AFB, Utah completed work on its 100th A-10 precision engagement upgrade in January 2008.The C model upgrades are to be completed in 2011.

Design

 Overview

The A-10 has superior maneuverability at low speeds and altitude, due to large wing area, high wing aspect ratio, and large ailerons. The large high aspect ratio wing also allows for short takeoffs and landings, permitting operations from primitive forward airfields near front lines. The aircraft can loiter for extended periods of time and operate under 1,000 ft ceilings with 1.5 mi  visibility. It typically flies at a relatively slow speed of 300 knots , which makes it a much better platform for the ground-attack role than fast fighter-bombers, which often have difficulty targeting small and slow-moving targets.

Engine exhaust passes over the aircraft’s horizontal stabilizer and between the twin tails, decreasing the A-10’s infrared signature and lowering the likelihood that the aircraft can be targeted by heat-seeking missiles. The placement of the engines behind the wings partially shields them from anti-aircraft fire. The leading edge of the wing is honeycomb panel construction to provide strength with minimal weight compromise. Honeycomb panels of this type on the A-10 include the flap shrouds, elevators, rudders and other sections of the fins.

The A-10 has integrally machined skin panels. Because the stringers are integral with the skin there are no join or seal problems. These panels, fabricated using computer controlled machining, reduce the time and hence the cost of production. Combat experience has shown that this type of panel is more resistant to damage. The skin is not load-bearing, so damaged skin sections can be easily replaced in the field, with makeshift materials if necessary.

The ailerons are at the far ends of the wings to gain greater rolling moment, as with many aircraft, but there are two distinguishing features. First, the ailerons are larger than is typical, almost 50% of the chord, providing improved control even at slow speeds. The aileron is also split, making it a deceleron.

The Thunderbolt II can be serviced and operated from bases with limited facilities near battle areas. An unusual feature is that many of the aircraft’s parts are interchangeable between the left and right sides, including the engines, main landing gear, and vertical stabilizers. The sturdy landing gear, low-pressure tires and large, straight wings allow operation from short rough strips even with a heavy ordnance load, allowing the aircraft to operate from damaged airbases. If runways are damaged in an attack, the A-10 can operate from taxiways, or straight roadway sections, such as Germany’s autobahn. The aircraft is designed to be refueled, rearmed, and serviced with minimal equipment. Also, most repairs can be done in the field.

The front landing gear is offset to the aircraft’s right due close proximity of the A-10’s main cannon. The cannon’s firing barrel lines up with the aircraft centerline. During ground taxi, the offset front landing gear causes the A-10 to have dissimilar turning radii. Turning to the right on the ground takes less distance than turning left.

Durability

A-10 is exceptionally tough. Its strong airframe can survive direct hits from armor-piercing and high-explosive projectiles up to 23 mm. The aircraft has triple redundancy in its flight systems, with mechanical systems to back up double-redundant hydraulic systems. This permits pilots to fly and land when hydraulic power or part of a wing is lost. Flight without hydraulic power uses the manual reversion flight control system; this engages automatically for pitch and yaw control, and under pilot control (manual reversion switch) for roll control. In manual reversion mode, the A-10 is sufficiently controllable under favorable conditions to return to base and land, though control forces are much higher than normal. The aircraft is designed to fly with one engine, one tail, one elevator and half a wing torn off. Its self-sealing fuel tanks are protected by fire-retardant foam. The A-10’s main landing gear is designed so that the wheels semi-protrude from their nacelles when the gear is retracted so as to make gear-up landings (belly landing) easier to control and less damaging to the aircraft’s underside. A belly landing would be required in the case of a landing gear failure. Additionally, the landing gear are all hinged toward the rear of the aircraft, so if hydraulic power is lost the pilot can drop the gear and a combination of gravity and wind resistance will open and lock the gear in place.

The cockpit and parts of the flight-control system are protected by 1,200 lb  titanium armor, referred to as a “bathtub”. The armor has been tested to withstand strikes from 23 mm cannon fire and some strikes from 57 mm rounds. It is made up of titanium plates with thicknesses from 0.5 to 1.5 inches  determined by a study of likely trajectories and deflection angles. This protection comes at a cost, though; the armor itself weighs almost 6% of the entire aircraft’s empty weight. To protect the pilot from the fragmentation likely to be created from impact of a shell, any interior surface of the tub that is directly exposed to the pilot is covered by a multi-layer nylon spall shield. The front windscreen and canopy are resistant to small arms fire.

Proof of the durability of the A-10 was shown when then-Captain Kim Campbell, USAF, flying a ground support mission over Baghdad during the 2003 invasion of Iraq on 7 April, suffered extensive flak damage to her A-10. Enemy fire damaged one of the A-10’s engines and crippled its hydraulic system, forcing the back-up mechanical system to operate the aircraft’s stabilizer and flight controls. Despite this, Campbell managed to fly it for an hour and landed it safely at the air base in manual reversion mode.

Powerplant

There are several reasons for the unusual location of the A-10’s General Electric TF34-GE-100 turbofan engines. First, the A-10 was expected to fly from forward air bases, often with semi-prepared substandard runways that presented a high risk of foreign object damage to the engines. The height of the engines lowers the chance that sand or stones will enter the inlet. This also allows engines to remain running, allowing for shorter servicing and rearming turn-around times by ground crew. Servicing and rearming are further helped by having wings closer to the ground than would be possible if the engines were wing-mounted. The position also reduces the infrared signature further, which is already low due to the engines’ 6:1 bypass ratio. Because of their high position, the engines are angled upward nine degrees to bring the combined thrust line closer to the aerodynamic center of the aircraft. This avoids trimming measures to counteract a nose-down pitching moment if the engines were parallel to the fuselage. The heavy engines require strong supports, so their pylons are connected to the airframe by four bolts.

The A-10’s fuel system components are protected in multiple ways. All four fuel tanks are near the center of the aircraft, reducing the likelihood that they will be hit or separated from the engines. The tanks are separate from the fuselage; thus, projectiles would need to penetrate the skin before reaching the tank. The refueling system is purged after use so that all fuel in the aircraft is protected. All fuel transfer lines self-seal if they are compromised. Most of the fuel system components are inside the tanks so that if a leak were to occur from the component the fuel would not be lost. If a tank does get damaged, check valves ensure that fuel does not flow into the compromised tank. Most importantly, reticulated polyurethane foam lines both the inner and outer sides of the fuel tanks, retaining debris and restricting fuel spillage in the event of damage. The other source of possible combustion, the engines, are shielded from the fuel system and the rest of the airframe by firewalls and fire extinguishing equipment. Even in the event of all four main tanks being holed and all contents lost, sufficient fuel is carried in two self-sealing sump tanks to allow flight for 230 miles.

Weapon systems

Although the A-10 can carry considerable disposable stores, its primary built-in weapon is the 30 mm GAU-8/A Avenger Gatling-type cannon. One of the most powerful aircraft cannon ever flown, it fires large depleted uranium armor-piercing shells. In the original design, the pilot could switch between two rates of fire: 2,100 or 4,200 rounds per minute; this was changed to a fixed rate of 3,900 rounds per minute.[ The cannon takes about half a second to come up to speed, so 50 rounds are fired during the first second, 65 or 70 rounds per second thereafter. The gun is precise; it can place 80% of its shots within a 40-foot  circle from 4,000 feet while in flight. The GAU-8 is optimized for a slant range of 4,000 feet with the A-10 in a 30 degree dive.

The fuselage of the aircraft is built around the gun. The gun’s firing barrel is placed at the 9 o’clock position so it is aligned on the aircraft’s centerline. The gun’s ammunition drum can hold up to 1,350 rounds of 30 mm ammunition, but generally holds 1,174 rounds. The damage caused by rounds firing prematurely due to impact of an explosive shell would be catastrophic, so a great deal of effort has been taken to protect the 5 feet 11.5 inch long drum. There are many armor plates of differing thicknesses between the aircraft skin and the drum, to detonate an incoming shell before it reaches the drum. A final layer of armor around the drum itself protects it from fragmentation damage. The gun is loaded by Syn-Tech’s linked tube carrier GFU-7/E 30 mm ammunition loading assembly cart; a vehicle unique to the A-10, the only aircraft that is armed with the GAU-8 cannon.

Another commonly used weapon is the AGM-65 Maverick air-to-surface missile, with different variations for either electro-optical (TV-guided) or infra-red targeting. The Maverick allows targets to be engaged at much greater ranges than the cannon, a safer proposition in the face of modern anti-aircraft systems. During Desert Storm, in the absence of dedicated forward-looking infrared cameras, the Maverick’s infra-red camera was used for night missions as a “poor man’s FLIR”. Other weapons include cluster bombs and Hydra rocket pods.[57] Although the A-10 is equipped to carry laser-guided bombs, their use is relatively uncommon. The A-10 has not been equipped with weapon control systems for accurate bombing. A-10s usually fly with an ALQ-131 ECM pod under one wing and two AIM-9 Sidewinder air-to-air missiles under the other wing for self-defense.

Modernization

The A-10 Precision Engagement Modification Program will update 356 A-10/OA-10s to the A-10C variant with a new flight computer, new glass cockpit displays and controls, two new 5.5-inch  color displays with moving map function and an integrated digital stores management system.

Other funded improvements to the A-10 fleet include a new data link, the ability to employ smart weapons such as the Joint Direct Attack Munition  and Wind Corrected Munitions Dispensor, and the ability to carry an integrated targeting pod such as the Northrop Grumman LITENING targeting pod or the Lockheed Martin Sniper XR Advanced Targeting Pod . Also included is the ROVER or remotely operated video enhanced receiver to provide sensor data to personnel on the ground.

 Colors and markings

Since the A-10 flies low to the ground and at subsonic speed, aircraft camouflage is important to make the aircraft more difficult to see. Many different types of paint schemes have been tried. These have included a “peanut scheme” of sand, yellow and field drab; black and white colors for winter operations and a tan, green and brown mixed pattern.

The two most common markings applied to the A-10 have been the European I woodland camouflage scheme and a two-tone gray scheme. The European woodland scheme was designed to minimise visibility from above, as the threat from hostile fighter aircraft was felt to outweigh that from groundfire. It uses dark green, medium green and dark grey in order to blend in with the typical European forest terrain and was used from the 1980s to the early 1990s. Following the end of the Cold War, and based on experience during the 1991 Gulf War, the air-to-air threat was no longer seen to be as important as that from ground fire, and a new color scheme, known as “Compass Ghost” was chosen to minimise visibility from below. This two-tone gray scheme has darker gray color on top, with the lighter gray on the underside of the aircraft, and started to be applied from the early 1990s.

Many A-10s also featured a “false” canopy painted in dark gray on the underside of the aircraft, just behind the gun. This form of automimicry is an attempt to confuse the enemy as to aircraft attitude and maneuver direction.

Weapon systems

 

Although the A-10 can carry considerable disposable stores, its primary built-in weapon is the 30 mm GAU-8/A Avenger Gatling-type cannon. One of the most powerful aircraft cannon ever flown, it fires large depleted uranium armor-piercing shells. In the original design, the pilot could switch between two rates of fire: 2,100 or 4,200 rounds per minute; this was changed to a fixed rate of 3,900 rounds per minute.[ The cannon takes about half a second to come up to speed, so 50 rounds are fired during the first second, 65 or 70 rounds per second thereafter. The gun is precise; it can place 80% of its shots within a 40-foot  circle from 4,000 feet while in flight. The GAU-8 is optimized for a slant range of 4,000 feet with the A-10 in a 30 degree dive.

The fuselage of the aircraft is built around the gun. The gun’s firing barrel is placed at the 9 o’clock position so it is aligned on the aircraft’s centerline. The gun’s ammunition drum can hold up to 1,350 rounds of 30 mm ammunition, but generally holds 1,174 rounds. The damage caused by rounds firing prematurely due to impact of an explosive shell would be catastrophic, so a great deal of effort has been taken to protect the 5 feet 11.5 inch long drum. There are many armor plates of differing thicknesses between the aircraft skin and the drum, to detonate an incoming shell before it reaches the drum. A final layer of armor around the drum itself protects it from fragmentation damage. The gun is loaded by Syn-Tech’s linked tube carrier GFU-7/E 30 mm ammunition loading assembly cart; a vehicle unique to the A-10, the only aircraft that is armed with the GAU-8 cannon.

 

 

Another commonly used weapon is the AGM-65 Maverick air-to-surface missile, with different variations for either electro-optical (TV-guided) or infra-red targeting. The Maverick allows targets to be engaged at much greater ranges than the cannon, a safer proposition in the face of modern anti-aircraft systems. During Desert Storm, in the absence of dedicated forward-looking infrared cameras, the Maverick’s infra-red camera was used for night missions as a “poor man’s FLIR”. Other weapons include cluster bombs and Hydra rocket pods.[57] Although the A-10 is equipped to carry laser-guided bombs, their use is relatively uncommon. The A-10 has not been equipped with weapon control systems for accurate bombing. A-10s usually fly with an ALQ-131 ECM pod under one wing and two AIM-9 Sidewinder air-to-air missiles under the other wing for self-defense.

 

 

Modernization

 

The A-10 Precision Engagement Modification Program will update 356 A-10/OA-10s to the A-10C variant with a new flight computer, new glass cockpit displays and controls, two new 5.5-inch  color displays with moving map function and an integrated digital stores management system.

Other funded improvements to the A-10 fleet include a new data link, the ability to employ smart weapons such as the Joint Direct Attack Munition  and Wind Corrected Munitions Dispensor, and the ability to carry an integrated targeting pod such as the Northrop Grumman LITENING targeting pod or the Lockheed Martin Sniper XR Advanced Targeting Pod . Also included is the ROVER or remotely operated video enhanced receiver to provide sensor data to personnel on the ground.

 

Operational history

 

 Introduction

The first unit to receive the A-10 Thunderbolt II was the 355th Tactical Training Wing, based at Davis-Monthan Air Force Base, Arizona in March 1976. The first unit to achieve full combat-readiness was the 354th Tactical Fighter Wing at Myrtle Beach AFB, South Carolina in 1978. Deployments of A-10As followed at bases both at home and abroad, including England AFB, Louisiana, Eielson AFB, Alaska, Osan Air Base, South Korea, and RAF Bentwaters/RAF Woodbridge, England. The 81st TFW of RAF Bentwaters/RAF Woodbridge operated rotating detachments of A-10s at four bases in Germany known as Forward Operating Locations: Leipheim, Sembach Air Base, Nörvenich, and Ahlhorn.

A-10s were initially an unwelcome addition to many in the Air Force. Most pilots switching to the A-10 did not want to because fighter pilots traditionally favored speed and appearance. In 1987, many A-10s were shifted to the forward air control  role and redesignated OA-10. In the FAC role the OA-10 is typically equipped with up to six pods of 2.75 inch  Hydra rockets, usually with smoke or white phosphorus warheads used for target marking. OA-10s are physically unchanged and remain fully combat capable despite the redesignation.

 Gulf War

The A-10 saw combat for the first time during the Gulf War in 1991, destroying more than 900 Iraqi tanks, 2,000 military vehicles, and 1,200 artillery pieces. A-10s shot down two Iraqi helicopters with the GAU-8 gun. The first of these occurred on 6 February 1991 when Captain Robert Swain shot down an Iraqi helicopter over Kuwait marking the A-10’s first air-to-air victory. Four A-10s were shot down during the war, all by surface-to-air missiles. Another three battle-damaged A-10s and OA-10As returned to base, but were written off, some due to additional damage sustained in crashed landings. The A-10 had a mission capable rate of 95.7%, flew 8,100 sorties, and launched 90% of the AGM-65 Maverick missiles fired in the conflict. Shortly after the Gulf War, the Air Force gave up on the idea of replacing the A-10 with a close air support version of the F-16.

 Bosnia and Kosovo

U.S. Air Force A-10 Thunderbolt II aircraft fired approximately 10,000 30 mm DU rounds in Bosnia-Herzegovina in 1994-1995. Following the seizure of some heavy weapons by Bosnian Serbs from a warehouse in Ilidza, a series of sorties were launched to locate and destroy the captured equipment. On 5 August 1994, two A-10s located and strafed an anti-tank vehicle. Afterwards, the Serbs agreed to return remaining heavy weapons. In August 1995, NATO launched an offensive called Operation Deliberate Force. A-10s flew close air support missions, attacking Serbian artillery, and positions. In late September, A-10s began flying patrols again.

A-10s returned to the region as part of Operation Allied Force in Kosovo beginning in March 1999. In March 1999, A-10s escorted and supported search and rescue helicopters in finding a downed F-117 pilot. The A-10s were deployed to support search and rescue missions. But the Warthogs began to receive more ground attack missions as the days passed. The A-10’s first successful attack in Operation Allied Force happened on 6 April 1999. A-10s remained until combat ended in late June 1999.

 Afghanistan and Iraq Wars

During the 2001 invasion of Afghanistan, A-10s did not take part in the initial stages. For the campaign against Taliban and Al Qaeda, A-10 squadrons were deployed to Pakistan and Bagram Air Base, Afghanistan beginning in March 2002. These A-10s participated in Operation Anaconda. Afterwards, A-10s remained in-country, fighting Taliban and Al Qaeda remnants.

Operation Iraqi Freedom began on 20 March 2003. Sixty OA-10/A-10 aircraft took part in early combat there.United States Air Forces Central issued Operation Iraqi Freedom: By the Numbers, a declassified report about the aerial campaign in the conflict on 30 April 2003. The A-10s had a mission capable rate of 85% in the war, and fired 311,597 rounds of 30 mm ammunition. A single A-10 was shot down near Baghdad International Airport by Iraqi fire late in the campaign. The A-10 also flew 32 missions in which the aircraft dropped propaganda leaflets over Iraq.

The A-10C first deployed to Iraq in the third quarter of 2007 with the 104th Fighter Squadron of the Maryland Air National Guard. The jets include the Precision Engagement Upgrade.The A-10C’s digital avionics and communications systems have greatly reduced the time to acquire a close air support target and attack it.

On March 25, 2010, an A-10 conducted the first flight of an aircraft with all engines powered by a biofuel blend. The flight, performed at Eglin Air Force Base, used a 50/50 blend of JP-8 and Camelina-based fuel.

The A-10 is scheduled to stay in service with the USAF until 2028 and possibly later,when it may be replaced by the F-35 Lightning II.

Variants

YA-10A 

Pre-production variant. 12 were built.

A-10A 

Single-seat close air support, ground-attack version.

OA-10A 

A-10As used for airborne forward air control.

YA-10B Night/Adverse Weather

Two-seat experimental prototype, for work at night and in bad weather. The one YA-10B prototype was conversion from a A-10A.

A-10C 

A-10As updated under the incremental Precision Engagement program.

 Operators

The A-10 has been flown exclusively by the United States Air Force and its Air Reserve components, the Air Force Reserve Command (AFRC) and the Air National Guard . The USAF operated 335 A-10 and OA-10 aircraft (188 in active duty, 96 in ANG, and 51 in AFRC, all variants) as of September 2008.The Air Force operates multiple A-10/OA-10 Active, National Guard, and Reserve squadrons.

Specifications A-10A

General characteristics

Fairchild Republic A-10 Thunderbolt II

Role                       Close air support, and ground-attack aircraft

Manufacturer    Fairchild-Republic

First flight          10 May 1972

Introduced        March 1977

Status                In service

Primary user    United States Air Force

Number built    716

Unit cost          $11.8 million

Crew: 1

Length: 53 ft 4 in 

Wingspan: 57 ft 6 in

Height: 14 ft 8 in 

Wing area: 506 ft²

Airfoil: NACA 6716 root, NACA 6713 tip

Empty weight: 24,959 lb 

Loaded weight: 30,384 lb  On CAS mission: 47,094 lb

On anti-armor mission: 42,071 lb 

Max takeoff weight: 50,000 lb 

Powerplant: 2× General Electric TF34-GE-100A turbofans, 9,065 lbf  each

Performance

Never exceed speed: 450 knots  at 5,000 ft  with 18 Mk 82 bombs

Maximum speed: 381 knots  at sea level, clean

Cruise speed: 300 knots

Stall speed: 120 knots

Combat radius:

On CAS mission: 250 nmi  at 1.88 hour single-engine loiter at 5,000 ft , 10 min combat

On anti-armor mission: 252 nmi , 40 nm  sea-level penetration and exit, 30 min combat

Ferry range: 2,240 nmi  with 50 knot  headwinds, 20 minutes reserve

Service ceiling: 45,000 ft

Rate of climb: 6,000 ft/min

Wing loading: 99 lb/ft²

Thrust/weight: 0.36

Armament

Guns: 1× 30 mm  GAU-8/A Avenger gatling cannon with 1,174 rounds

Hardpoints: 11 (8× under-wing and 3× under-fuselage pylon stations) with a capacity of 16,000 lb  and provisions to carry combinations of:

Rockets:

4× LAU-61/LAU-68 rocket pods (each with 19× / 7× Hydra 70 mm rockets, respectively)

4× LAU-5003 rocket pods (each with 19× CRV7 70 mm rockets)

6× LAU-10 rocket pods (each with 4 × 5.0 in Zuni rockets)

Missiles:

2× AIM-9 Sidewinders air-to-air missiles for self-defense

8× AGM-65 Maverick air-to-surface missiles

Bombs:

Mark 80 series of unguided iron bombs or

Mk 77 incendiary bombs or

BLU-1, BLU-27/B Rockeye II, Mk20, BL-755 and CBU-52/58/71/87/89/97 cluster bombs or

Paveway series of Laser-guided bombs or

Joint Direct Attack Munition (A-10C) or

Wind Corrected Munitions Dispenser (A-10C)

Other:

SUU-42A/A Flares/Infrared decoys and chaff dispenser pod or

AN/ALQ-131 & AN/ALQ-184 ECM pods or

Lockheed Martin Sniper XR & LITENING targeting pods (A-10C) or 2× 600 US gallon Sargent Fletcher drop tanks for extended range/loitering time.

Avionics

AN/AAS-35(V) Pave Penny laser tracker pod (mounted beneath right side of cockpit) for use with Paveway LGBs

Head-up display (HUD) for improved technical flying and air-to-ground support.

 Nicknames

The A-10 Thunderbolt II received its popular nickname “Warthog” from the pilots and crews of the USAF attack squadrons who flew and maintained it. The A-10 is the last of Republic’s jet attack aircraft to serve with the USAF. The Republic F-84 Thunderjet was nicknamed the “Hog”, F-84F Thunderstreak nicknamed “Superhog”, and the Republic F-105 Thunderchief tagged “Ultra Hog”. A less common nickname is the “Tankbuster”. The saying Go Ugly Early has been associated with the aircraft in reference to calling in the A-10 early in combat.

 Notable appearances in media

 Aircraft in fiction

The A-10 Thunderbolt is utilized against the Decepticon Scorponok in the 2007 film, Transformers.A-10s were also used by the human resistance effort against the machines of Skynet in the 2009 film Terminator Salvation.

Operational history

 

 Introduction

 

The first unit to receive the A-10 Thunderbolt II was the 355th Tactical Training Wing, based at Davis-Monthan Air Force Base, Arizona in March 1976. The first unit to achieve full combat-readiness was the 354th Tactical Fighter Wing at Myrtle Beach AFB, South Carolina in 1978. Deployments of A-10As followed at bases both at home and abroad, including England AFB, Louisiana, Eielson AFB, Alaska, Osan Air Base, South Korea, and RAF Bentwaters/RAF Woodbridge, England. The 81st TFW of RAF Bentwaters/RAF Woodbridge operated rotating detachments of A-10s at four bases in Germany known as Forward Operating Locations: Leipheim, Sembach Air Base, Nörvenich, and Ahlhorn.

A-10s were initially an unwelcome addition to many in the Air Force. Most pilots switching to the A-10 did not want to because fighter pilots traditionally favored speed and appearance. In 1987, many A-10s were shifted to the forward air control  role and redesignated OA-10. In the FAC role the OA-10 is typically equipped with up to six pods of 2.75 inch  Hydra rockets, usually with smoke or white phosphorus warheads used for target marking. OA-10s are physically unchanged and remain fully combat capable despite the redesignation.

 Gulf War

The A-10 saw combat for the first time during the Gulf War in 1991, destroying more than 900 Iraqi tanks, 2,000 military vehicles, and 1,200 artillery pieces. A-10s shot down two Iraqi helicopters with the GAU-8 gun. The first of these occurred on 6 February 1991 when Captain Robert Swain shot down an Iraqi helicopter over Kuwait marking the A-10’s first air-to-air victory. Four A-10s were shot down during the war, all by surface-to-air missiles. Another three battle-damaged A-10s and OA-10As returned to base, but were written off, some due to additional damage sustained in crashed landings. The A-10 had a mission capable rate of 95.7%, flew 8,100 sorties, and launched 90% of the AGM-65 Maverick missiles fired in the conflict. Shortly after the Gulf War, the Air Force gave up on the idea of replacing the A-10 with a close air support version of the F-16.

 

 Bosnia and Kosovo

U.S. Air Force A-10 Thunderbolt II aircraft fired approximately 10,000 30 mm DU rounds in Bosnia-Herzegovina in 1994-1995. Following the seizure of some heavy weapons by Bosnian Serbs from a warehouse in Ilidza, a series of sorties were launched to locate and destroy the captured equipment. On 5 August 1994, two A-10s located and strafed an anti-tank vehicle. Afterwards, the Serbs agreed to return remaining heavy weapons. In August 1995, NATO launched an offensive called Operation Deliberate Force. A-10s flew close air support missions, attacking Serbian artillery, and positions. In late September, A-10s began flying patrols again.

A-10s returned to the region as part of Operation Allied Force in Kosovo beginning in March 1999. In March 1999, A-10s escorted and supported search and rescue helicopters in finding a downed F-117 pilot. The A-10s were deployed to support search and rescue missions. But the Warthogs began to receive more ground attack missions as the days passed. The A-10’s first successful attack in Operation Allied Force happened on 6 April 1999. A-10s remained until combat ended in late June 1999.

 Afghanistan and Iraq Wars

 

During the 2001 invasion of Afghanistan, A-10s did not take part in the initial stages. For the campaign against Taliban and Al Qaeda, A-10 squadrons were deployed to Pakistan and Bagram Air Base, Afghanistan beginning in March 2002. These A-10s participated in Operation Anaconda. Afterwards, A-10s remained in-country, fighting Taliban and Al Qaeda remnants.

Operation Iraqi Freedom began on 20 March 2003. Sixty OA-10/A-10 aircraft took part in early combat there.United States Air Forces Central issued Operation Iraqi Freedom: By the Numbers, a declassified report about the aerial campaign in the conflict on 30 April 2003. The A-10s had a mission capable rate of 85% in the war, and fired 311,597 rounds of 30 mm ammunition. A single A-10 was shot down near Baghdad International Airport by Iraqi fire late in the campaign. The A-10 also flew 32 missions in which the aircraft dropped propaganda leaflets over Iraq.

The A-10C first deployed to Iraq in the third quarter of 2007 with the 104th Fighter Squadron of the Maryland Air National Guard. The jets include the Precision Engagement Upgrade.The A-10C’s digital avionics and communications systems have greatly reduced the time to acquire a close air support target and attack it.

On March 25, 2010, an A-10 conducted the first flight of an aircraft with all engines powered by a biofuel blend. The flight, performed at Eglin Air Force Base, used a 50/50 blend of JP-8 and Camelina-based fuel.

 

The A-10 is scheduled to stay in service with the USAF until 2028 and possibly later,when it may be replaced by the F-35 Lightning II.

 

 

Variants

 

YA-10A 

Pre-production variant. 12 were built.

A-10A 

Single-seat close air support, ground-attack version.

OA-10A 

A-10As used for airborne forward air control.

YA-10B Night/Adverse Weather

Two-seat experimental prototype, for work at night and in bad weather. The one YA-10B prototype was conversion from a A-10A.

A-10C 

A-10As updated under the incremental Precision Engagement program.

 

 Operators

 

The A-10 has been flown exclusively by the United States Air Force and its Air Reserve components, the Air Force Reserve Command (AFRC) and the Air National Guard . The USAF operated 335 A-10 and OA-10 aircraft (188 in active duty, 96 in ANG, and 51 in AFRC, all variants) as of September 2008.The Air Force operates multiple A-10/OA-10 Active, National Guard, and Reserve squadrons.

Specifications A-10A

General characteristics

Fairchild Republic A-10 Thunderbolt II

Role                       Close air support, and ground-attack aircraft

Manufacturer    Fairchild-Republic

First flight          10 May 1972

Introduced        March 1977

Status                In service

Primary user    United States Air Force

Number built    716

Unit cost          $11.8 million

Crew: 1

Length: 53 ft 4 in 

Wingspan: 57 ft 6 in

Height: 14 ft 8 in 

Wing area: 506 ft²

Airfoil: NACA 6716 root, NACA 6713 tip

Empty weight: 24,959 lb 

Loaded weight: 30,384 lb  On CAS mission: 47,094 lb

On anti-armor mission: 42,071 lb 

Max takeoff weight: 50,000 lb 

Powerplant: 2× General Electric TF34-GE-100A turbofans, 9,065 lbf  each

Performance

Never exceed speed: 450 knots  at 5,000 ft  with 18 Mk 82 bombs

Maximum speed: 381 knots  at sea level, clean

Cruise speed: 300 knots

Stall speed: 120 knots

Combat radius:

On CAS mission: 250 nmi  at 1.88 hour single-engine loiter at 5,000 ft , 10 min combat

On anti-armor mission: 252 nmi , 40 nm  sea-level penetration and exit, 30 min combat

Ferry range: 2,240 nmi  with 50 knot  headwinds, 20 minutes reserve

Service ceiling: 45,000 ft

Rate of climb: 6,000 ft/min

Wing loading: 99 lb/ft²

Thrust/weight: 0.36

Armament

Guns: 1× 30 mm  GAU-8/A Avenger gatling cannon with 1,174 rounds

Hardpoints: 11 (8× under-wing and 3× under-fuselage pylon stations) with a capacity of 16,000 lb  and provisions to carry combinations of:

Rockets:

4× LAU-61/LAU-68 rocket pods (each with 19× / 7× Hydra 70 mm rockets, respectively)

4× LAU-5003 rocket pods (each with 19× CRV7 70 mm rockets)

6× LAU-10 rocket pods (each with 4 × 5.0 in Zuni rockets)

Missiles:

2× AIM-9 Sidewinders air-to-air missiles for self-defense

8× AGM-65 Maverick air-to-surface missiles

Bombs:

Mark 80 series of unguided iron bombs or

Mk 77 incendiary bombs or

BLU-1, BLU-27/B Rockeye II, Mk20, BL-755 and CBU-52/58/71/87/89/97 cluster bombs or

Paveway series of Laser-guided bombs or

Joint Direct Attack Munition (A-10C) or

Wind Corrected Munitions Dispenser (A-10C)

Other:

SUU-42A/A Flares/Infrared decoys and chaff dispenser pod or

AN/ALQ-131 & AN/ALQ-184 ECM pods or

Lockheed Martin Sniper XR & LITENING targeting pods (A-10C) or 2× 600 US gallon Sargent Fletcher drop tanks for extended range/loitering time.

Avionics

AN/AAS-35(V) Pave Penny laser tracker pod (mounted beneath right side of cockpit) for use with Paveway LGBs

Head-up display (HUD) for improved technical flying and air-to-ground support.

 Nicknames

The A-10 Thunderbolt II received its popular nickname “Warthog” from the pilots and crews of the USAF attack squadrons who flew and maintained it. The A-10 is the last of Republic’s jet attack aircraft to serve with the USAF. The Republic F-84 Thunderjet was nicknamed the “Hog”, F-84F Thunderstreak nicknamed “Superhog”, and the Republic F-105 Thunderchief tagged “Ultra Hog”. A less common nickname is the “Tankbuster”. The saying Go Ugly Early has been associated with the aircraft in reference to calling in the A-10 early in combat.

 Notable appearances in media

 Aircraft in fiction

The A-10 Thunderbolt is utilized against the Decepticon Scorponok in the 2007 film, Transformers.A-10s were also used by the human resistance effort against the machines of Skynet in the 2009 film Terminator Salvation.

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M1 Abrams: Tip of the Spear

May 9, 2010

 

The M1 Abrams is a third-generation main battle tank produced in the United States. The M1 is named after General Creighton Abrams, former Army Chief of Staff and Commander of US military forces in Vietnam from 1968 to 1972. It is a well armed, heavily armored, and highly mobile tank designed for modern armored ground warfare. Notable features of the M1 Abrams include the use of a powerful gas turbine engine, the adoption of sophisticated composite armor, and separate ammunition storage in a blow-out compartment for crew safety. It is one of the heaviest tanks in service, weighing in at close to 68 short tons (almost 62 metric tons).The M1 Abrams entered U.S. service in 1980, replacing the 105 mm gun, full tracked M60 Patton. It did, however, serve for over a decade alongside the improved M60A3, which had entered service in 1978. Three main versions of the M1 Abrams have been deployed, the M1, M1A1, and M1A2, incorporating improved armament, protection and electronics. These improvements, as well as periodic upgrades to older tanks have allowed this long-serving vehicle to remain in front-line service. The M1A3 is currently under development. It is the principal main battle tank of the United States Army and Marine Corps, and the armies of Egypt, Kuwait, Saudi Arabia, Australia, and in 2010 Iraq. The M1 Abrams is anticipated to be in U.S. service until the 2050s, approximately 70 years after entering U.S. service.

  History

 Development

 

The first attempt to replace the aging M60 tank was the MBT-70, developed in partnership with West Germany in the 1960s. The MBT-70 was very ambitious, and had various ideas that ultimately proved unsuccessful. As a result of the imminent failure of this project, the U.S. Army introduced the XM803. This succeeded only in producing an expensive system with capabilities similar to the M60.Congress canceled the MBT-70 in November and XM803 December 1971, and redistributed the funds to the new XM815 later renamed the XM1 Abrams after General Creighton Abrams. Prototypes were delivered in 1976 by Chrysler Defense and General Motors armed with the license-built version of the 105 mm Royal Ordnance L7 gun along with a Leopard 2 for comparison. The Chrysler Defense design was selected for development as the M1. In 1979, General Dynamics Land Systems Division purchased Chrysler Defense.3273 M1 Abrams were produced 1979-85 and first entered US Army service in 1980. It was armed with the license-built version of the 105 mm Royal Ordnance L7 gun. An improved model called the M1IP was produced briefly in 1984 and contained small upgrades. The M1IP models were used in the Canadian Army Trophy NATO tank gunnery competition in 1985 and 1987.About 6000 M1A1 Abrams were produced from 1986–92 and featured the M256 120 mm smoothbore cannon developed by Rheinmetall AG of Germany for the Leopard 2, improved armor, and a CBRN protection system. 

 Gulf War

 

As the Abrams entered service in the 1980s, they would operate alongside M60A3 within the United States military, and with other NATO tanks in numerous Cold War exercises. These exercises usually took place in Western Europe, especially West Germany, but also in some other countries like South Korea. During such training, Abrams crews honed their skills for use against the men and equipment of the Soviet Union. However, by 1991 the USSR had collapsed and the Abrams would have its trial by fire in the Middle East.The Abrams remained untested in combat until the Gulf War in 1991. A total of 1,848 M1A1s were deployed to Saudi Arabia. The M1A1 was superior to Iraq’s Soviet-era T-55 and T-62 tanks, as well as Iraqi-assembled Russian T-72s, and locally-produced copies (Asad Babil tank). The T-72s, like most Soviet export designs, lacked night vision systems and then-modern rangefinders, though they did have some night fighting tanks with older active infrared systems or floodlights—just not the latest starlight scopes and passive infrared scopes as on the Abrams. Only 23 M1A1s were taken out of service in the Gulf. Some others took minor combat damage, with little effect on their operational readiness. Very few Abrams tanks were hit by enemy fire, and there was only one fatality, along with a handful of woundings as a result.

The M1A1 was capable of making kills at ranges in excess of 2,500 metres (8,200 ft). This range was crucial in combat against tanks of Soviet design in Desert Storm, as the effective range of the main gun in the Soviet/Iraqi tanks was less than 2,000 metres (6,600 ft) . This meant Abrams tanks could hit Iraqi tanks before the enemy got in range—a decisive advantage in this kind of combat. In friendly fire incidents, the front armor and fore side turret armor survived direct APFSDS hits from other M1A1s. This was not the case for the side armor of the hull and the rear armor of the turret, as both areas were penetrated at least in two occasions by friendly DU ammunition during the Battle of Norfolk.

 

 Interwar upgrades

 

The M1A2 was a further improvement of the M1A1 with a commander’s independent thermal viewer and weapon station, position navigation equipment, digital data bus and a radio interface unit. The M1A2 SEP (System Enhancement Package) added digital maps, FBCB2 (Force XXI Battlefield Command Brigade and Below) capabilities, and an improved cooling system to maintain crew compartment temperature with the addition of multiple computer systems to the M1A2 tank.Further upgrades included depleted uranium armor for all variants, a system overhaul that returns all A1s to like-new condition (M1A1 AIM), a digital enhancement package for the A1 (M1A1D), a commonality program to standardize parts between the U.S. Army and the Marine Corps (M1A1HC) and an electronic upgrade for the A2 (M1A2 SEP).During Operations Desert Shield and Desert Storm and for Bosnia, some M1A1s were modified with armor upgrades. The M1 can be equipped with mine plow and mine roller attachments if needed. The M1 chassis also serves as a basis for the Grizzly combat engineering vehicle and the M104 Wolverine heavy assault bridge.Over 8,800 M1 and M1A1 tanks have been produced at a cost of US$2.35–$4.30 million per unit, depending on the variant. 

 Iraq War

 Further combat was seen during 2003 when US forces invaded Iraq and deposed the Iraqi leader Saddam Hussein. As of March 2005, approximately 80 Abrams tanks were forced out of action by enemy attacks. Nevertheless, the campaign saw very similar performance from the tank with no Abrams crew member being lost to hostile fire during the invasion of Iraq, although several tank crew members were later killed by roadside bombs during the occupation that followed.The most lopsided achievement of the M1A2s was the destruction of seven T-72 Lion of Babylon tanks in a point-blank skirmish (less than 50 yards ) near Mahmoudiyah, about 18 miles south of Baghdad, with no losses for the American side. In addition to the Abrams’ already heavy armament, some crews were also issued M136 AT4 shoulder-fired anti-tank weapons under the assumption that they might have to engage heavy armor in tight urban areas where the main gun could not be brought to bear.

 

Following lessons learned in Desert Storm, the Abrams and many other US combat vehicles used in the conflict were fitted with Combat Identification Panels to reduce friendly fire incidents. These were fitted on the sides and rear of the turret, with flat panels equipped with a four-cornered ‘box’ image on either side of the turret front . Some Abrams were also fitted with a secondary storage bin on the back of the existing bustle rack on the rear of the turret referred to as a bustle rack extension to enable the crew to carry more supplies and personal belongings.

 

Many Abrams (irrecoverable due to loss of mobility or other circumstances) were destroyed by friendly forces to prevent their capture, usually by other Abrams, who often found them very difficult to destroy despite their firepower.A majority of Abrams damaged post-invasion were by Improvised explosive devices.Some Abrams were disabled by Iraqi infantrymen in ambushes during the invasion. Some troops employed short-range anti-tank rockets and fired at the tracks, rear and top. Other tanks were put out of action when struck in critical places by heavy machine gun rounds.Due to the vulnerability of tanks in urban combat, the Tank Urban Survival Kit, or TUSK, is being issued to some M1 Abrams. It is intended to improve fighting ability in urban environments. 

 Future

The M1A3 Abrams is in the early design period with the U.S. Army. The Army aims to build prototypes by 2014 and to begin to field the first combat-ready M1A3s by 2017.

 

 Camouflage

 

Unlike earlier US military vehicles from World War II through Vietnam, which used a scheme of dark brownish green known as “olive drab” with large white stars, prototypes and early production M1 (105 mm gun) & M1-IP models used the flat medium green paint; and the large white insignia stars have transitioned to much smaller black markings. Some units painted their M1s with the older MERDC 4-color paint scheme but the turn-in requirements for these tanks required repainting them to solid green. Therefore, even though a large number of the base model M1s were camouflaged in the field, few or none exist today.M1A1s (120 mm gun) came from the factory with the NATO 3 color camouflage Black/Med-Green/Dark-Brown CARC paint jobs. Today M1A1s are given the NATO three color paint job during rebuilds. M1s and M1A1s deployed to Desert Storm were hastily painted desert tan. Some, but not all, of these tanks were re-painted to their “authorized” paint scheme. M1A2s built for Middle Eastern countries were painted in desert tan.Some M1 series tanks are being painted desert tan for service in Iraq and some are not. Replacement parts (roadwheels, armor skirt panels, drive sprockets, etc.) are painted overall green, which can sometimes lead to vehicles with a patchwork of green and desert tan parts.

 

 Concealment

 

The turret is fitted with two six-barreled smoke grenade launchers (USMC M1A1s use an eight-barreled version). These can create a thick smoke that blocks both vision and thermal imaging, and can also be armed with chaff. The engine is also equipped with a smoke generator that is triggered by the driver. When activated, fuel is sprayed on the engine manifold, creating the thick smoke. However, due to change from diesel as a primary fuel to the use of JP-8, this system is disabled on most Abrams today, because JP-8 causes the tanks to catch fire when sprayed on the manifold.

 

 Active protection system

In addition to the advanced armor, some Abrams are equipped with a Missile Countermeasure Device that can impede the function of guidance systems of semi-active control line-of-sight (SACLOS) wire and radio guided anti-tank missiles (Russian AT-3, AT-4, AT-5, AT-6 and the like) and thermally and infrared guided missiles (ATGM).[19] This device is mounted on the turret roof in front of the loader’s hatch, and can lead some people to mistake Abrams fitted with these devices for the M1A2 version, since the Commander’s Independent Thermal Viewer on the latter is mounted in the same place, though the MCD is box-shaped and fixed in place as opposed to cylindrical and rotating like the CITV.

 

 Armor

 

The Abrams is protected by armor based on the British-designed Chobham armor, a further development of the British ‘Burlington’ armor. Chobham is a composite armor formed by spacing multiple layers of various alloys of steel, ceramics, plastic composites, and kevlar, giving an estimated maximum (frontal turret) 1,320–1,620 millimetres (52–64 in) of RHAe versus HEAT (and other chemical energy rounds) and 940–960 mm (37–38 in) versus kinetic energy penetrators. It may also be fitted with reactive armor over the track skirts if needed (as in the Urban Survival Kit) and Slat armor over the rear of the tank and rear fuel cells to protect against ATGMs. Protection against spalling is provided by a Kevlar liner. Beginning in 1987, M1A1 tanks received improved armor packages that incorporated depleted uranium  mesh in their armor at the front of the turret and the front of the hull. Armor reinforced in this manner offers significantly increased resistance towards all types of anti-tank weaponry, but at the expense of adding considerable weight to the tank, as depleted uranium is 1.7 times more dense than lead.

 

The first M1A1 tanks to receive this upgrade were tanks stationed in Germany, since they were the first line of defense against the Soviet Union. US-based tank battalions participating in Operation Desert Storm received an emergency program to upgrade their tanks with depleted uranium armor immediately before the onset of the campaign. M1A2 tanks uniformly incorporate depleted uranium armor, and all M1A1 tanks in active service have been upgraded to this standard as well, the added protection from the depleted uranium armor is believed to be equivalent to 24 inches  of RHA. The strength of the armor is estimated to be about the same as similar western, contemporary main battle tanks such as the Leopard 2. In the Persian Gulf War, Abrams tanks survived multiple hits at relatively close ranges from Iraqi Lion of Babylon tanks and ATGMs. M829A1 “Silver Bullet” APFSDS rounds from other M1A1 Abrams were unable to penetrate the front and side armor (even at close ranges) in friendly fire incidents as well as an incident in which another Abrams tried to destroy an Abrams that got stuck in mud and had to be abandoned.

 

 Damage control

In the chance that the Abrams does suffer damage resulting in a fire in the crew compartment, the tank is equipped with a halon fire-suppression system that automatically engages and extinguishes fires in seconds.Fuel and ammunition are in armored compartments with blowout panels to protect the crew from the risk of the tank’s own ammunition cooking off if the tank is damaged.

 

 Armament

 Primary armament

M68A1 rifled gun

The main armament of the original model M1 was the M68A1 105 mm rifled tank gun firing a variety of high explosive anti-tank, high explosive, white phosphorus and an anti-personnel (multiple flechette) round. This gun is a license-built version of the British Royal Ordnance L7 gun. While being a reliable weapon and widely used by many NATO nations, a cannon with lethality beyond the 3-kilometer (1.9 mi) range was needed to combat newer armor technologies. To attain that lethality, projectile diameter needed to be increased. The M68A1’s performance in terms of accuracy and armor-piercing penetration is on par with the M256A1 up to 3 kilometers (1.9 mi) out, but beyond that range the 105 mm projectile lacks the kinetic energy to defeat modern armor packages.

M256 smoothbore gun

The main armament of the M1A1 and M1A2 is the M256A1 120 mm smoothbore gun, designed by Rheinmetall AG of Germany, manufactured under license in the United States by Watervliet Arsenal, New York. The M256A1 is a variant of the Rheinmetall 120 mm L/44 gun carried on the German Leopard 2 on all variants up to the Leopard 2A5. Leopard 2A6 replaced the L/44 barrel with a longer L/55.The M256A1 fires a variety of rounds. The M829A2 was developed specifically to address the threats posed by a Soviet T-90 or T-80U tank equipped with Kontakt-5 Explosive Reactive Armor. It also fires HEAT shaped charge rounds such as the M830, the latest version of which (M830A1) incorporates a sophisticated multi-mode electronic sensing fuse and more fragmentation which allows it to be used effectively against armored vehicles, personnel, and low-flying aircraft. The Abrams uses a manual loader, due to the belief that having a crewman reload the gun is faster and more reliable.[citation needed] and because autoloaders do not allow for separate ammunition storage in the turret.[citation needed] The fourth tank crewman on the Abrams also provides additional support for maintenance, observation post/listening post (LP/OP) operations, and other tasks.

The new M1028 120 mm anti-personnel canister cartridge was brought into service early for use in the aftermath of the 2003 invasion of Iraq. It contains 1,098 3⁄8-inch (9.5 mm) tungsten balls which spread from the muzzle to produce a shotgun effect lethal out to 600 meters (2,000 ft). The tungsten balls can be used to clear enemy dismounts, break up hasty ambush sites in urban areas, clear defiles, stop infantry attacks and counter-attacks and support friendly infantry assaults by providing covering fire. The canister round is also a highly effective breaching round and can level cinder block walls and knock man-sized holes in reinforced concrete walls for infantry raids at distances up to 75 meters (246 ft).

 

In addition to this, the new XM1111 (Mid-Range-Munition Kinetic Energy) is also in development. Essentially a cannon-fired guided round, it has a range of roughly 12 km and uses a KE warhead which is rocket assisted in its final phase of flight. This is intended to be the best penetrator yet, an improvement over the US 3rd generation DU penetrator (estimated penetration 790 mm (31 in)).

 

 Secondary armament

 

The Abrams tank has three machine guns:

 

A .50 cal. (12.7 mm) M2HB machine gun is in front of the commander’s hatch. On the M1, M1IP and M1A1, this gun is on a powered mount and can be fired using a 3× magnification sight, known as the Commander’s Weapon Station (CWS for short), while the vehicle is “buttoned up” with all its hatches closed to protect the crew. On the M1A2 & M1A2SEP, this gun is on a flex mount (seen at right), the Commander having to expose himself to fire the weapon manually. With the forthcoming TUSK addon kit, an M2HB or a Mk 19 grenade launcher can be mounted on the CROWS remote weapons platform (similar to the Protector M151 remote weapon station used on the Stryker family of vehicles). The upgrade variant called M1A1 Abrams Integrated Management (AIM) equips the .50 caliber gun with a thermal sight for accurate night and other low-visibility shooting.

A 7.62 mm M240 machine gun is in front of the loader’s hatch on a skate mount. Some of these have been fitted with gun shields during the ongoing conflict in Iraq as seen in the image at right, as well as night-vision scopes for low-visibility engagements.

A second 7.62 mm M240 machine gun is in a coaxial mount to the right of the main gun. The coaxial MG is aimed and fired with the same computer fire control system used for the main gun.

(Optional) A second coaxial 12.7 mm M2HB machine gun can be mounted directly above the main gun in a remote weapons platform as part of the TUSK upgrade kit.

For the US Army in previous years, the Abrams usually maintained the provision for storing an M16 rifle or M4 carbine inside the turret in case the crew is required to leave the tank under potentially hostile conditions; while the crewmen were supplied with the M9 Beretta pistol as a personal sidearm. Considering the current (often dismounted) role of American armored crewmen and contemporary operating environments, though, current US Army crews maintain a rifle or carbine for each crewman. During Iraqi Freedom some crews were also issued M136 AT4 shoulder-fired anti-tank weapons under the assumption that they might have to engage heavy armor in tight urban areas where the main gun could not be brought to bear.

 

 Aiming

 

The Abrams is equipped with a ballistic fire-control computer that uses user and system-supplied data from a variety of sources, to compute, display, and incorporate the three components of a ballistic solution – lead angle, ammunition type, and range to the target, to accurately fire the tank. These three components are determined using a YAG rod laser rangefinder, crosswind sensor, a pendulum static cant sensor, data concerning performance and flight characteristics of each specific type of round, tank-specific boresight alignment data, ammunition temperature, air temperature, barometric pressure, a muzzle reference system (MRS) that determines and compensates for barrel droop at the muzzle due to gravitational pull and barrel heating due to firing or sunlight, and target speed determined by tracking rate tachometers in the Gunner’s or Commander’s Controls Handles. All of these factors are computed into a ballistic solution and updated 30 times per second. The updated solution is displayed in the Gunner’s or Tank Commander’s field of view in the form of a reticle in both day and Thermal modes. The ballistic computer manipulates the turret and a complex arrangement of mirrors so that all one has to do is keep the reticle on the target and fire to achieve a hit. Proper lead and gun tube elevation are applied to the turret by the computer, greatly simplifying the job of the Gunner.The fire-control system uses these data to compute a firing solution for the gunner. The ballistic solution generated ensures a hit percentage greater than 95 percent at nominal ranges. Either the commander or gunner can fire the main gun. Additionally, the Commander’s Independent Thermal Viewer (CITV) on the M1A2 can be used to locate targets and pass them on for the gunner to engage while the commander scans for new targets. In the event of a malfunction or damage to the primary sight system, the main and coaxial weapons can be manually aimed using a telescopic scope boresighted to the main gun known as the Gunner’s Auxiliary Sight (GAS). The GAS has two interchangeable reticles; one for HEAT and MPAT (MultiPurpose AntiTank) rounds and one for APFSDS and STAFF (Smart Target-Activated Fire and Forget) ammunition. Turret traverse and main gun elevation can be accomplished with manual handles and cranks in the event of a Fire Control System or Hydraulic System failure. The commander’s M2 .50 caliber machine gun on the M1 and M1A1 is aimed by a 3x magnification sight incorporated into the Commander’s Weapon Station (CWS), while the M1A2 uses either the machine gun’s own iron sights, or a remote aiming system such as the CROWS system when used as part of the TUSK (Tank Urban Survival Kit). The loader’s M240 machine gun is aimed either with the built-in iron sights or with a thermal scope mounted on the machine gun.

 

 Mobility 

The M1 Abrams is powered by a 1,500 shaft horsepower (1,100 kW) Honeywell AGT 1500 (originally made by Lycoming) gas turbine, and a six speed (four forward, two reverse) Allison X-1100-3B Hydro-Kinetic automatic transmission, giving it a governed top speed of 45 mph (72 km/h) on paved roads, and 30 mph (48 km/h) cross-country. With the engine governor removed, speeds of around 60 mph (97 km/h) are possible on an improved surface; however, damage to the drive train (especially to the tracks) and an increased risk of injuries to the crew can occur at speeds above 45 mph (72 km/h). The tank for all intents and purposes was built around this engine.[26] The tank can be fueled with diesel fuel, kerosene, any grade of motor gasoline, JP-4 jet fuel, or JP-8 jet fuel; the US Army uses JP-8 jet fuel in order to simplify logistics. The Royal Australian Armoured Corps’ M1A1 AIM SA uses diesel fuel; it is cheaper and makes practical sense for Australian military logistics.

 

 

Driving controls the gas turbine propulsion system has proven quite reliable in practice and combat, but its high fuel consumption is a serious logistic issue (starting up the turbine alone consumes nearly 10 US gallons (38 l) of fuel).[27] The engine burns more than 1 US gallon (3.8 l) per mile and 12 US gallons (45 l) per hour when idle.[28] The high speed, high temperature jet blast emitted from the rear of M1 Abrams tanks makes it difficult for the infantry to proceed shadowing the tank in urban combat. The turbine is very quiet when compared to diesel engines of similar power output and produces a significantly different sound from a contemporary diesel tank engine, reducing the audible distance of the sound, thus earning the Abrams the nickname “whispering death” during its first REFORGER exercise.

 Honeywell was developing another gas turbine engine with General Electric for the XM2001 Crusader program that was also to be a replacement for the AGT-1500 engine already in the Abrams tank. The new LV100-5 engine is lighter and smaller (43% fewer parts) with rapid acceleration, quieter running and no visible exhaust. It also features a 33% reduction in fuel consumption (50% less when idle) and near drop-in replacement. The Abrams-Crusader Common Engine Program was shelved when the Crusader program was canceled, however Phase 2 of Army’s PROSE (Partnership for Reduced O&S Costs, Engine) program calls for further development of the LV100-5 and replacement of the current AGT-1500 engine. Future US tanks may return to reciprocating engines for propulsion, as 4-stroke diesel engines have proven quite successful in other modern heavy tanks, e.g. the Leopard 2, Challenger 2 and Merkava.Using a high power density 330 cc (20 cu in) Wankel rotary engine modified to use diesel and military grade jet fuel, TARDEC developed a 220-pound (100 kg) Auxiliary Power Unit designed to fit into the M1 Abrams, replacing an existing battery pack that weighs about 500 pounds (230 kg). The new APU will also be more fuel efficient. The installation of the first APUs is expected to start in 2009.

 

A provision exists that the Abrams be able to transport passengers in tank desant with the turret stabilization device off. One Infantry squad carrying only their battle gear may ride the rear of the turret. The soldiers have the option of using ropes and equipment straps as a field-expedient Infantry rail to provide handholds and snap links to secure themselves to the turret. The Squad leader, team leaders, grenadiers sit on the left and right sides of the turret, while the riflemen, and automatic riflemen sit at the rear. If and when enemy contact is made, the tank conceals itself allowing the infantry to dismount.

 

 Strategic mobility

 

Strategic mobility is the ability of the tanks of an armed force to arrive in a timely, cost effective, and synchronized fashion. The Abrams can be carried by a C-5 Galaxy or a C-17 Globemaster III. The limited capacity (two combat-ready in a C-5, one combat-ready tank in a C-17) caused serious logistical problems when deploying the tanks for the First Gulf War, though there was enough time for 1,848 tanks to be transported by ship.The Abrams is also transportable by truck, namely the M1070 Heavy Equipment Transporter (HET). The HET can operate on highways, secondary roads, and cross-country. The HET accommodates the 4 tank crewmen.

 

The government-owned Lima Army Tank Plant in Lima, Ohio, currently manufactures the Abrams, the Detroit Arsenal Tank Plant in Warren, Michigan manufactured it from 1982 to 1996. It costs upwards of US$5 million a tank

 

 Tank Urban Survival Kit

 The Tank Urban Survival Kit (TUSK), is a series of improvements to the M1 Abrams intended to improve fighting ability in urban environments. Historically, urban and other close battlefields have been the worst place for tanks to fight—a tank’s front armor is much stronger than that on the sides, top, or rear, and in an urban environment, attacks can come from any direction, and attackers can get close enough to reliably hit weak points in the tank’s armor, or get sufficient elevation to hit the top armor square on.Armor upgrades include reactive armor on the sides of the tank and slat armor (similar to that on the Stryker) on the rear to protect against rocket-propelled grenades and other shaped charge warheads.A Transparent Armor Gun Shield and a thermal sight system are added to the loader’s top-mounted M240B 7.62 mm machine gun, and a Kongsberg Gruppen Remote Weapon Turret carrying a .50 caliber machine gun (again similar to that used on the Stryker) is in place of the tank commander’s original .50 caliber machine gun mount, wherein the commander had to expose himself to fire the weapon manually. An exterior telephone allows supporting infantry to communicate with the tank commander.The TUSK system is a field-installable kit that allows tanks to be upgraded without needing to be recalled to a maintenance depot.While the reactive armor may not be needed in most situations in maneuver warfare, items like the rear slat armor, loader’s gun shield, infantry phone (which saw use on Marine Corps M1A1s as early as 2003), and Kongsberg Remote Weapons Station for the .50 caliber machine gun will be added to the entire M1A2 fleet over time.

 

On August 29, 2006, General Dynamics Land Systems received a US Army order for 505 Tank Urban Survivability Kits (TUSK) for Abrams main battle tanks supporting operations in Iraq, under a US$45 million contract. The add-on kit will be provided for M1A1 and M1A2-series tanks to enhance crew survivability in urban environments. The kit ordered by the Army consists of a Loader’s Armor Gun Shield (LAGS), a Tank Infantry Phone (TIP), Abrams Reactive Armor Tiles (ARAT), a Remote Thermal Sight (RTS) and a Power Distribution Box (PDB). Deliveries are expected to be complete by April 2009.

 

Under a separate order, the US Army awarded General Dynamics Armament and Technical Products (GDATP) US$30 million to produce reactive armor kits to equip M1A2. The total contract value could reach $59 million if all contract options are exercised. The reactive tiles for the M1 will be locally produced at GDATP’s Burlington Technology Center. Tiles will be produced at the company’s reactive armor facility in Stone County Operations, McHenry, Miss. On December 8, 2006 the U.S. Army added Counter Improvised Explosive Device enhancements to the M1A1 and M1A2 TUSK, awarding GDLS U.S. $11.3 million, part of the $59 million package mentioned above. In December GDLS also received an order amounting about 40% of a US$48 million order for loader’s thermal weapon sights being part of the TUSK system improvements for the M1A1 and M1A2 Abrams Tanks.

 

 Operators

 Australia – 59 M1A1SA (hybrids, mix equipment used by US.Army tanks and U.S.M.C. tanks, without DU layers in armor) tanks were bought from the United States in 2006, to replace the Leopard AS1 in 2007.

 Egypt – 1005 M1A1 (downgraded, without DU layers in armor) tanks co-produced by the USA and Egypt for the Egyptian army.

 Iraq – 140 M1A1M’s (downgraded, without DU layers in armor) on order, to be delivered by 2011. Currently 22 US.Army M1A1’s are leased for training.

 Kuwait – 218 M1A2s (downgraded, without DU layers in armor)

 Saudi Arabia – 373 eventually to be upgraded to M1A2S (without DU layers in armor)

 United States – Approximately 6,000 M1A1 and M1A2 variants including both Army and Marine Corps inventory + 3268 M1 and M1IP variants, not used in storage, waiting for upgrade to M1A2SEP variant (most of them) or rebuild to specialised vehicles.

1,174 M1A2 and M1A2SEP variants (Army inventory)

4,393 M1A1 variants (Army inventory). Under upgrade process to M1A1SA variant.

403 M1A1HC’s variants (Marine Corps inventory). Under upgrade process to M1A1FEP.

Type Main battle tank

Place of origin  United States

Service history

In service 1980–present
 
 
Production history

Designer Chrysler Defense
Manufacturer Lima Army Tank Plant (1980-present)
Detroit Arsenal Tank Plant (1982-1996)
Unit cost US$6.21 million (M1A2 / FY99)
Number built 9,000+
 
Specifications
 
Weight 67.6 short tons 
Length Gun forward: 32.04 ft
Hull length: 26.02 ft 
Width 12 ft 
Height 8 ft 
Crew 4 (commander, gunner, loader, driver)
 
Armor Chobham, RH armor, steel encased depleted uranium mesh plating
Primary armament 105 mm M68 rifled cannon (M1) 120 mm M256 smoothbore cannon (M1A1, M1A2, M1A2SEP))
Secondary armament 1 x .50-caliber  M2HB heavy machine gun
2 x 7.62 mm  M240 machine guns (1 pintle-mounted, 1 coaxial)
Engine Honeywell AGT1500C multi-fuel turbine engine
1,500 shp (1,120 kW)
Power/weight 24.5 hp/metric ton
Transmission Allison DDA X-1100-3B
Suspension Torsion bar
Ground clearance 1 ft 7 in (M1, M1A1) 1 ft 5 in (M1A2)
Fuel capacity 500 US gallons 
Operational range 289 mi With NBC system: 279 mi 
Speed Road: 42 mph Off-road: 30 mph