Flightline: 187 - Boeing AH-64 Apache
Designed to replace the AH-1 Huey Cobra, the Apache has been the US Army's main anti-tank/attck helicopter for the last 35 years.
Backstory, Backstory, Backstory...
In 1964 the US Army opened the Advanced Aerial Fire Support System (AAFSS) program, which sought to push development of a helicopter designed from the ground-up as a dedicated attack platform (all previous choppers, including the AH-1 Cobra, were adapted from transports or scouts, with varying degrees of effectiveness). Of the designs submitted, the Sikorski S-66 and Lockheed CL-840 were selected for further consideration, with the CL-840 being awarded a contract for 10 prototypes on 23 March 1966. Once testing of the YAH-56 started however, problems started cropping up, including a weight problem and a dangerous instability in the rotor system, which led to the destruction of prototype #3 and the death of the test pilot on 12 March 1969. The accident was traced to the disabling of safety mechanisms designed to prevent a dangerous vibration in the rotors, known as a "half-p hop", which were then exacerbated by a pilot-induced oscillation. The Army demanded that Lockheed correct the problem, as well as continuing over-weight issues, but the contractor's fixes were judged to be either ineffective or would slow the program (already behind schedule and over budget), and as a result the AH-56 was canceled on 19 May 1969.
The Army started over from square one, and in 1972 initiated the Advanced Attack Helicopter (AAH) program. Informed by experiences in Vietnam, the AAH called for a helicopter with more firepower than the AH-1 could carry, more performance and the ability to conduct nap-of-the-earth flight. Requirements for reliability, survivability and life-cycle costs were modeled on the Utility Tactical Transport Aircraft System (UTTAS) program, which had resulted in the UH-60 Black Hawk. Initially, a load of 16 TOW missiles were called for, but this was later changed to the new HELiborne Laser, FIRE-and-forget missile that was under development, which matured into the AGM-114 Hellfire missile. Eventually, five companies submitted proposals, Bell, Boeing-Vertol, Hughes, Lockheed and Sikorsky. Bell's Model 409 and Hughes' Model 77 were selected for the final fly-off, and contracts for the construction two prototypes each of the YAH-63 and YAH-64 were awarded in July of 1973
Prototype of the Bell YAH-63, showing its unusual tricycle landing gear. | Photo: US Army
One of the YAH-64 prototypes, which initially had a T-tail.
An intensive flight test program followed the maiden flights of the YAH-63 and YAH-64, which happened on 1 October and 30 September 1975 respectively. In 1976 the Army selected the Hughes Model 77/YAH-64 as the winner of the program, judging the Model 77's main rotor to be more damage tolerant and citing the stability of the chopper's landing gear over that of the Bell 409. A contract was then awarded to Hughes for three additional YAH-64A pre-production models, as well as to bring the two prototypes and the ground test unit up to the same standards. The pre-production models and rebuilt prototypes had a new tail unit, swapping the position of the tail rotor and stabilator, and were fitted with weapons and sensors, including the laser designator for the new AGM-114 Hellfires. Contractor's tests continued into 1981, after which the YAH-64s, now given the name Apache (following Army tradition, helicopters are named after American Indian tribes), were transferred to the Army for the second phase of operational testing. The tests were successful and the AH-64A approved for production in 1982, with the first production helicopter leaving Hughes' plant in 1983. The following year, Hughes Helicopters was purchased by McDonnell Douglas, bringing the Apache under their banner.
A YAH-64A pre-production model during a test flight in 1982. | Photo: US Army
Design and specifications
Orthograph of the AH-64A. | Illustration: Dr Dan Saranga
The AH-64 follows the same basic planform as the AH-1 and other attack/anti-tank helicopters, having a narrow fuselage with the crew siting in tandem near the nose. The helicopter is 58' 2" long (the fuselage itself is 49' 5" long), with a rotor diameter of 48' and a total height of 12' 8". Empty the AH-64 weighs almost eleven-thousand four hundred pounds, and at full TO weighs twenty-three thousand pounds. The Apache has a four-bladed main rotor as well as a four-bladed tail rotor in a non-orthogonal alignment. The rotors are designed to withstand rounds up 23mm, as is the crew compartment, which also features shields between the gunner and pilot so that one is more likely to survive enemy fire. The fuselage incorporates 2,500lbs of armor, and the fuel tanks are self-sealing. The AH-64, like the Black Hawk, is designed to meet the requirements of MIL-STD-1290, which sets crashworthiness standards for US Army helicopters.
Power for the AH-64 family is provided by two GE T-700 series turboshafts, which develop 1,690 shaft horsepower. The Apache cruises at 165mph, and has a maximum speed of 182mph. Under ideal conditions (temp of 59 °F), the AH-64 can climb at 1,775fpm and has a service ceiling of 21,000 feet, while on a 'hot' day (temp of 70 °F or more) the climb rate drops to 1,595fpm and the ceiling is reduced to just over 19,000 feet. Combat range is 296mi, while the addition of two auxiliary tanks gives a ferry range of almost 1,200mi. For longer deployments, up to 6 Apaches can be loaded into a C-5 Galaxy, while three AH-64s can be carried by the C-17 Globemaster III.
An AH-64 is unloaded from a C-5A Galaxy during an exercise in Alaska in 1998. | Photo: USAF
Soldiers and airmen transport an Army AH-64 Apache helicopter after unloading it from an Air Force C-17 Globemaster III during "large package week" operations at Pope Army Airfield, N.C., Feb. 4, 2015. | Photo: USAF
One of the Apache's most revolutionary, and visually distinctive, features is the Target Acquisition and Designation Sights, Pilot Night Vision System (TADS/PNVS) which is mounted in the helicopter's nose. The TADS, mounted in the lower turret, contains stabilized electro-optical sensors as well as a laser rangefinder and a laser designator. The sensors include a thermographic camera as well as a monochrome daylight TV camera (later updated to a full-color model). This system allows the Weapons Systems Officer to find targets, even at night or when obscured by smoke, vegetation or in poor weather, and to designate them for the AGM-114 Hellfire missiles. The PNVS, located in the upper turret, contains an IR camera which feeds to the pilot, allowing them to fly the Apache at night or in adverse conditions. The PVNS and TADS operate independently of each other, and while the former has a range of motion of +/- 90° horizontally and +20°/-45° vertically, while the latter can rotate +/- 120° horizontally and +30°/-80° vertically, and both are slaved to the pilot's and gunner's head movements and feed into their helmet mounted displays.
Front view of an AH-64 showing the TADS and PNVS. | Photo: Guinnog
Another innovation introduced with the AH-64 is the Integrated Helmet and Display Sighting System (IHADSS) which both mounts a display onto the crew's helmets which can overlay data and imagery from the TADS and PNVS and allow the pilot and/or WSO to aim the helicopter's gun and TADS/PNVS simply by looking where they want. This is accomplished by a series of targets embedded in the helmet which are tracked by lasers in the cockpit.
Photo of an Apache pilot showing the helmet-mounted display monocle and two of the IHADSS targets (the two circles protected by shades near her index and pinky fingers). | Photo: UK MOD
AH-64s are armed with an M230E1 30mm Chain Gun, with a 1,200 round capacity. Additionally, there are four pylons on the stub wings which can carry four-round racks for AGM-114 Hellifire missiles, pods for Hydra or CRV7 unguided or guided APKWS 70mm rockets, or drop tanks. Compatibility tests were carried out with AIM-9 Sidewinders and AGM-122 Sidearm anti-radiation missile, but were not followed-up on. Wingtip launchers for AIM-92 Stinger missiles are also available, although usually are used only on export Apaches.
Various combat load-outs for the AH-64, and their effect on aircraft speed, endurance and range. | Illustration: FAS
Operational History and upgrades
Acceptance of the first production AH-64As began in January 1984 with training beginning in April with the 7th Battalion, 17th Cavalry Brigade at Fort Hood, Texas. Two units fielded Apaches during joint exercises in Europe in 1987. During Operation JUST CAUSE in 1989 the AH-64 was deployed to Panama, flying 240 combat hours, mainly at night. The following year, Operation DESERT SHEILD saw half of the US Army's Apaches deployed to Saudi Arabia following the Iraqi invasion of Kuwait. While the F-117 and Tomahawk cruise missile received all the press coverage for their parts in the start of the Air War on 17 January 1991, a group of eight AH-64s, along with four MH-53 Pave Low III helos acting as pathfinders, destroyed numerous Iraqi radar sites along the border, opening pathways for Coalition strike aircraft. During the 24-28 February ground campaign to eject Iraqi forces from Kuwait, 277 Apaches destroyed 278 tanks as well as numerous APCs and other Iraqi vehicles. Clips from the TADS/PNVS of Iraqi tanks being destroyed by Hellfire missiles were shared with the American public on nightly news broadcasts. One AH-64 was destroyed during the conflict when it was hit by an RPG at close range; the crew survived. Although proven combat effective, the tempo of Apache operations in the Gulf War also proved to be hard on the aircraft, with maintenance crews struggling to keep up. In order to provide spares for operational missions, all other Apache units were grounded for the duration of Desert Storm; even still, AH-64s in the theater flew only 1/5th of their planned flight hours.
AH-64A Apaches and OH-58D Kiowa Warriors of the 101st Airborne Division stand ready at a forward operating base during Operation Desert Storm. | Photo: US Army
Two upgrades of the Apache were proposed in the wake of the 1991 Gulf War, both of which would alleviate some deficiencies encountered: The AH-64B upgrade was to add Global Positioning Systems and other navigational upgrades, new radios, and upgraded rotor blades. This model was canceled in 1992, but the upgrades made it to the fleet through other programs. The AH-64C, originally the B+, would have also added a glass cockpit, new sensors and digital radio upgrades. Overlap between the C model upgrade and the forthcoming AH-64D Longbow Apache saw the Army discontinue using the "C" identifier in 1993, from then on all upgraded Apaches were referred to as "D"s. Development of what became the Longbow Apache began in 1990, and incorporated the enhancements planned for the B and C upgrades with more powerful -700C engines and the AN/APG-78 millimeter-wave radar (MWR) located in a radome mounted over the rotors. This positioning allowed the Longbow to survey a battlefield while the bulk of the helicopter remained behind cover, similar to the OH-58 Kiowa's mast-mounted sight (MMS). The Longbow MMR could track up to 128 targets and attack 16 simultaneously using AGM-114L Hellfires, a radar guided, fire-and-forget variant of the Apache's weapon of choice. The Longbow was also networked, allowing one AH-64D to share targeting data with other Apaches as well as other allied units. The first AH-64D took its maiden flight on 15 April 1992, with trials concluding in 1995 with a contract being signed to upgrade 232 A models to Longbow standards. The first production AH-64D flew on 17 March 1997, with delivery to the Army two weeks later.
During the 1999 war in Kosovo, 24 AH-64As were deployed to Albania as part of Task Force HAWK , first being flown to Ramstein AB in Germany before self-deploying to the forward base at Tirana's Nënë Tereza Airport. Both Austria and Switzerland refused to allow the helicopters to fly through their airspace, so the force flew west to France, then followed the Alps down to the Mediterranean before turning east for Italy. Poor conditions at the landing area at the airport forced the Apaches to hold in Italy while perforated steel planking was laid, the helicopters of the 11th Aviation Group arrived in Albania. Ultimately, the TF Hawk AH-64s did not see combat during the Kosovo crisis, owing to a number of factors including a lack of training, a shortage of night vision goggles and auxiliary fuel tanks, and stronger than anticipated air defenses.
After the 9/11 attacks, AH-64s were deployed to Afghanistan as part of Operation ENDURING FREEDOM, where they were the preferred Army platform for Close Air Support (CAS) due to their accuracy. By this time most of the A models had been upgraded to D specs, but flew combat operations mainly without the Longbow radar as there was little threat of armored targets.
An AH-64 engages Taliban fighters with its 30mm Chain Gun. | Video: US Army
Apaches were again deployed to Iraq during Operation IRAQI FREEDOM, with mixed results. A planned strike on the Iraqi Republican Guard Medina Division ended in failure, with 29 of the 31 AH-64s involved damaged versus only 12 of the expected 90 Iraqi tanks destroyed. From this point on Apaches were used to flush out Iraqi positions, which were then engaged by airstrikes and artillery. By 2011 the AH-64 fleet had amassed 3 million flight hours from the maiden flight in 1975.
In 2011 deliveries began of the AH-64E Apache Guardian, which incorporated lessons learned from Afghanistan and Iraqi. Based on the Longbow, the E model incorporated more powerful T700-710D engines, a revised transmission, new composite rotor blades, improved landing gear and fully instrument flight rule capacity. Upgrades to the Longbow radar allow over-water detection, and improved communications and datalinks allow Guardian pilots to control and accept surveillance from unmanned aerial vehicles, allowing the AH-64E to network with other Apaches and Army UAVs to gather their own intelligence and attack targets from standoff range. Six-hundred D model Apaches were upgraded to E spec, and 56 new build aircraft replaced losses. Production of the Guardian is expected to conclude in 2026, at which point Boeing is expected to close the Apache line in anticipation of the Army switching to an attack variant of the Future Vertical Lift aircraft.
The Israeli Air Force began acquiring AH-64As in 1990; by 2000 the fleet of Israeli Peten ("Cobra") numbered forty-two aircraft. The IAF has ordered up to 48 AH-64D, which are called Saraph ("Venomous or Fiery Winged Serpent"), but the deliveries have been repeatedly blocked by the US, and in 2007 the Israeli government put future orders on hold. Instead, the existing A models have been upgraded, as the AH-64Ai, to near AH-64D standards. In addition to adding domestically sources avionics, the AH-64Ai and AH-64D Saraph carry Rafael Spike anti-tank missiles, which the US Army has also adopted as of 2020.
An Israeli Saraph armed with Spike NLOS missiles and carrying an auxiliary fuel tank. | Photo: IDF
In the wake of Operation Desert Storm, both the Kingdom of Saudi Arabia and the United Arab Emirates purchased Apaches, with the Royal Saudi Land Force receiving 12 AH-64A in 1991, while the UAE purchased 30 A models between 1991 and 1994. Negotiations began between the Saudis and US in 2006 to remanufacture the RSLF Apaches to D model spec, by 2008 the US had approved a purchase of 12 AH-64D, and in 2010 the request had grown by 70 more Longbows. The UAE meanwhile had begun their own Longbow upgrade program in 2008, followed up by a purchase of 37 Apache Guardians in 2016.
Egypt also purchased a force of Apaches after the Gulf War, acquiring 36 AH-64A in 1995. These helicopters were upgraded to AH-64D standard in 2000 with the exception of the Longbow radar, which was blocked. In 2009 the US reversed course, allowing Egypt to buy 12 AH-64D Block II helos, with full Longbow capability. In 2018 a purchase of 10 AH-64E was approved as well.
European operators were also interested in the AH-64, with the Royal Netherlands Air Force showing interest in the late 1980s in purchasing up to 52 helicopters. As a result of a flyoff in 1994 between the Apache, Eurocopter Tiger and AH-1 SuperCobra, the RNLAF ordered 30 AH-64D, with deliveries beginning in 1998. Dutch Apaches are fitted with the Apache Modular Aircraft Survivability Equipment (AMASE) self-protection system to counter infrared missiles. In 2018 the RNLAF signed a contract to upgrade their Apaches to E spec.
The British Royal Army operates the WAH-64, a modified version of the AH-64D Longbow built under license by Westland in 1998 and known in UK service as the Apache AH1. The WAH-64 differs from other Apaches in having RR/Turbomeca RTM322 turboshafts, a folding mechanism for the rotor blades as well as an anti-icing system, and locally sourced avionics. In 2015 a contract was granted to upgrade 50 of the WAH-64 to AH-64E spec, including the use of GE T700 engines. A follow-up sale of 50 US-built AH-64Es was signed in 2016.
A WAH-64D Longbow helicopter displays at Kemble Air Day 2008, Kemble Airport, Gloucestershire, England. | Photo: Adrian Pingstone
Japan also license builds a version of the Apache Longbow, the AH-64DJP, produced beginning in 2006 by Fuji Heavy Industries. The initial order of 50 helicopters was cut to just 13 units due to costs. The JGSDF began a program in 2017 to upgrade the targeting systems of their Apaches.
Other operators of the Apache include Greece, Singapore, Kuwait, India, Indonesia, the Republic of China (Taiwan), the Republic of Korea (South Korea), and Qatar. An offer for 24 AH-64s was tendered to the new Iraqi government in 2013, but was not acted on and expired in 2014. The Australian Army selected the AH-64E to replace it's Tiger ARH, with the first of 29 to be delivered in 2026. Morocco has also signed an order for 24 of the Apache Guardian, with an option for 12 more.
A Marine Apache?
During the 1980s, there was interest from the US Navy and Marines in acquiring a navalized version of the AH-64, with alterations made to the landing gear, weatherproofing, and folding rotor blades the main changes. The Navy and Marines conducted a joint two-week evaluation of the Apache, including shipboard operations, but a lack of funding resulted in the USMC keeping their AH-1 Cobra in to the 21st century. The idea has percolated up again from time to time, with the occasional training exercise being held to familiarize Navy and Marine crews with the AH-64, and British experiences operating the Apache AH1 from HMS Ocean have peaked Army interest as well.
An Army Apache operating from amphibious assault ship USS Nassau (LHA 4) during Joint Shipboard Weapons and Ordnance (JSWORD) training in 2005. | Photo: US Navy
The Apache has made a significant mark in the public's mind since even before the 1991 Gulf War, being a focus of the 1990 film 'Fire Birds' (aka 'Wings of the Apache'), and has appeared in 2008's 'The Incredible Hulk' and 2009's 'G.I. Joe: The Rise of Cobra'. The AH-64 has also been featured in video games like 1986's Gunship and its sequel Gunship 2000, Digital Integration's 1995 Apache, Jane's AH-64D Longbow from 1996 and Desert Strike from 1992. The Renegade GoBot Warpath disguises himself as an AH-64, and was released as a Super GoBots action figure in 1986.
Box art for the GoBots Renegade character Warpath. | Photo: Hasbro