The beginnings of the AH-64D Apache Longbow (on the image) date back to 1988 when work began to develop series of improvements and modernizations to be applied to the AH-64A. This package of improvements led to a new variant known as the AH-64B, but after the 1991 Gulf War, this variant was cancelled but many of the modifications were installed on the serial AH-64A. Later, more funds were approved to continue with the improvements and this ended in the appearance of a new variant called AH-64C, which had implemented all the improvements of the AH-64D except for the new T700-GE-701C engines and the mast-mounted radar.Since 1990, all AH-64As began receiving the new T700-GE-701C engines and in 1993 the AH-64C designation was abandoned. Then, taking into account that the only difference between variant C and D was the radar, and that this could be exchanged between all helicopters, it was decided to unify both variants and call them AH-64D Apache Longbow (on the image). It can be stated that this new variant is actually the second of the AH-64 helicopter family, since variants B and C were only interim to differentiate the modernization programs of variant A.The main difference with the AH-64A is the mast-mounted AN/APG-78 Longbow millimeter-wave fire-control radar (FCR), but it also incorporated a Radar Frequency Interferometer (RFI) and a target acquisition system, all installed in the interior of the dome, which reaches 136 kg in weight. In addition to the new radar, the AH-64D Longbow carried new 1,890 hp T700-GE-701C engines and an enlarged forward fuselage to carry new navigation and internet communication equipment that improved its survival capabilities. A new Plessey AN/ASN-157 Doppler and a new integrated GPS/INS along with EMI protection were also incorporated.The AN/APG-78 radar has three main modes of use, air-ground, air-air and terrain mapping and scans in a 270º arc (in 90º sectors) in air-to-ground mode, while in air-to-air mode it scans in 360º. This radar can track up to 128 targets and can engage up to 16 targets simultaneously and classifies detected targets into 6 different categories: tracking vehicle, wheeled vehicle, air defense, rotorcraft, fixed-wing aircraft and unknown. The radar works in Ka band and has a range of 8 km and can also transfer its information to ground units and other Apaches to be able to carry out combined attacks on a single target if necessary.The Apache Longbow also have an improved cockpit with color multifunction screens and new symbols within the “glass cockpit” concept, which tries to suppress all irrelevant information from the crew members. This new concept is called “management by exception” and it basically means that if the turbines and systems are working properly, there is no need to distract the crew. Of course, if a malfunction is detected, it will be reported immediately and the actions to be taken. The new equipment allows safe low-level flight and precise pre-signaling of the objectives by the acquisition system in order to direct it for rapid identification. In addition, the Radar Frequency Interferometer (RFI) perceives enemy air defense threats from any angle and alerts the crew. Also a new auxiliary power unit (APU) that doubles the generation of electrical energy was installed.In August 1990 the development of the AH-64D was given free rein and in 1992 McDonnell Douglas modified four AH-64As by installing the Longbow radar, flying the first prototype on April 15, 1992, although the radar did not begin to be tested until late 1993. During testing, the AH-64D Apache Longbow was shown to be four times more lethal than the former Apache and seven times more likely to survive on the battlefield. After successful tests, its manufacture was approved in October 1995, with the first one being delivered on March 31, 1997.In August 1996, contract was signed that established the modification of 232 AH-64As into AH-64Ds over a period of 5 years for an amount of $1.9-billion. However, in 1999 the US Army increased this number to 501 helicopters, but this number increased over the years and it is estimated that in 2010 there were 634 AH-64D Apache Longbows in service. The first 501 US Army AH-64Ds were all remanufactured AH-64As built between 1997 and 2006, however in June 2007 the first of a new series of 45 Apache Longbow helicopters was delivered. Shortly after, in October of this same year, the first of the 96 AH-64A converted to the AH-64D Block II model was delivered. In 2011, with the arrival of the AH-64E Apache Guardian variant, the US Army ordered the conversion of all Apache Longbows to this new variant.The operational life of the Apache Longbow has been quite long and logically, it has needed various modernizations that would allow it to remain effective and lethal. For example, in 2003 the replacement of the TADS/PNVS system with a new Lockheed Martin’s Arrowhead (MTADS) targeting system was approved. This system is integrated by a second-generation long-wave Forward Looking Infrared (FLIR) sensor and the VNsight system and was integrated with the AH-64D Longbow in June 2005.This new FLIR has three fields of view, dual field of view pilotage FLIR, a target tracker, a charge-coupled device TV camera, an electronic zoom and auto-boresight. On the oher hand, VNsight is a low-light-level TV (LLLTV) integrated into the Apache‘s Modernized Pilot Night Vision Sensor (M-PNVS) that allows pilots to see flashes of tracer rounds, markers, lasers and beacons that they could not locate before. This new system improves the Apache’s survivability and improves its combat capacity as it allows the crew to see their own laser spot while designating targets, significantly improving accuracy.In August 2012 a total of 24 AH-64D Longbows received a new Ground Fire Acquisition System (GFAS). This system consists of two sensor pods and a thermographic camera that, together with the helicopter’s other sensors, allow it to locate muzzle flashes from firearms and missiles. This system has a 120º visual field and operates under any light conditions. In 2014, the replacement of all black and white imaging systems with modern high-resolution color imagery systems was also approved, and in 2016 the Arowhead systems began to be modernized to improve their range and field of vision.Regarding the armament of the AH-64D Longbow, it is practically the same as the A variant, but logically modernized and updated. In 2005 it began using the AGM-114N Hellfire missile, equipped with “metal augmented charge (MAC)” warhead, which is basically a thermobaric type warhead equipped with a delayed fuze that causes a large pressure wave on the target. This missile has an extended range of up to 11 km and two guidance systems: millimeter-wave radar seeker or semi-active laser homing. This missile is specially designed to attack soft-skinned targets, ship-borne targets and buildings. Of course, the AH-64D can use the entire range of Hellfiremissiles currently available.Despite having Stinger and Sidewinder air-to-air missiles available, the American Apache Longbows have rarely carry them. However, the Japanese AH-64DJP do mount Stinger missiles on a regular basis. In late 2015 the US Army acquired the Advanced Precision Kill Weapon System (APKWS) guided 70 mm rockets to add to the Apache‘s arsenal. New systems have also been tested such as the MBDA Brimstone anti-armor missile with satisfactory results and even in June 2017 a high energy laser system from Raytheon was tested. Boeing has also developed some such weapons for use against drones and communications equipment. At the end of 2023, the US Army had 450 AH-64Ds in service, which will be converted to the Apache Guardian variant progressively.Apache Longbow has participated in all operations in Afghanistan and Iraq from 2001 until the withdrawal of United States Forces in 2021. Usually the AH-64D operated without having the Longbow radar installed due to the lack of armored targets and the fact that almost all missions were close air support (CAS) to ground troops. During these 20 years of operations, the Apache have had many highlights, but also some shadows regarding their effectiveness and performance.In 2001 they were at the forefront of all major operations within Operation Enduring Freedom in Afghanistan. These missions were usually carried out in small groups of Apache subject to strict rules of engagement that gave them little room to deviate from the planned mission and often ended without the success they should have had if the command had allowed them more operational flexibility. During these operations, between 2001 and 2011, 4 US Army AH-64Ds were lost in accidents, according to official sources, and it is unknown if any were shot down by enemy fire.As in Afghanistan, the AH-64D was involved in the most difficult phases of Operation Iraqi Freedom carried out in Iraq between 2003 and 2011. During these operations the US Army lost 20 Apache Longbows, 11 in accidents and 9 shot down by enemy fire. It is estimated that at the end of this campaign the entire fleet of AH-64 Apache, including all variants, had reached 3,000,000 flight hours, having carried out around 1.3 million in real combat missions, figures unattainable by any other attack helicopter in the world.The United Kingdom was one of the first countries to become interested in the AH-64A Apache, specifically in 1989. However, it was not until 1995 when the Apache was chosen as the new attack helicopter for the British Army Air Corps. The contract established the acquisition of 67 aircraft, 8 manufactured by Boeing and another 59 shipped in kits that would be assembled by Westland Helicopters at its plant in Yeovil, Somerset in England. These helicopters were initially designated “Westland WAH-64 Apache Mk.1” (on the image), but later changed to “Apache AH Mk.1” or “Apache AH1” and they were actually similar to the AH-64D, although with some differences.The main difference between the WAH-64 Apache Mk.1 (on the image) and its American brothers is that they have Rolls-Royce Turbomeca RTM322 engines. These engines are more powerful than the American ones and develop 2,100 shp each compared to the 1,890 shp of the General Electric T700-701C, but due to the gearbox installed, the engines cannot be used at full power for long periods of time. Additionally, the British Apache have a folding blade mechanism for use from ships and different communications and electronic defense equipment. Communications are entrusted to the BOWMAN secure communications system from General Dynamics, which allows the WAH-64 to communicate with any British military unit. On the other hand, the Helicopter Integrated Defensive Aids System (HIDAS) manufactured by Selex ES (now Leonardo) is responsible for electronic countermeasures and anti-missile defensive measures.The first WAH-64 Apache (on the image) assembled by Westland was delivered in September 1998, but it was not until January 2001 that the first Apache AH1s were fully operational. In addition to the high cost, the installation of the “made in UK” equipment entailed serious development problems that slowed down its entry into service, even leading to requests for the program to be cancelled. The last of the 67 contracted helicopters was delivered in July 2004, ending a program that ended up costing £4.1 billion, of which £3.1 billion was for the aircraft.WAH-64 (on the image) have received some improvements and upgrades such as the installation of the Arrowhead (MTADS) targeting system in 2005 or the installation of new external fuel tanks with ballistic protection in 2010. In addition, the installation of additional controls to improve the agility and an Integrated Ammunition and Fuel unit that improves the range of the helicopter has been studied, although this is at the cost of carrying less ammunition for the 30mm gun. Initially, it was expected to maintain the WAH-64 fleet at least until 2030, but in 2005 work began to maintain operability once this date was reached.Among the options considered, it was proposed to purchase new Block III helicopters, extend their operational life until 2040 through modernization program, or rebuild the fleet to the AH-64E Apache Guardian standard. Finally, in July 2016 it was decided to modernize 50 WAH-64s (on the image) to the AH-64E variant, with 38 aircraft to be delivered in 2017 and the other 12 in 2019. Of course, these deadlines have not been met and in February 2024 only the first 38 modernized helicopters had been delivered. All 50 helicopters will be rebuilt by Boeing to the AH-64E v6 (version 6) variant.The WAH-64s participated in operations carried out in Afghanistan, where one of them crashed on September 4, 2008 in Helmand province. They carried out close support missions quite successfully and were highly valued by the ground troops, but unfortunately the same thing happened to them as their American cousins in 1991. Keeping them operational required an effort and a cost much higher than expected and this led to the fact that in November 2008, there were only 20 Apaches available to perform combat missions. After the withdrawal of British forces from Afghanistan in December 2014, it was decided to put 16 of the 66 remaining WAH-64s (on the image) into long-term storage, leaving 50 WAH-64s operational.The ability to operate from ships is exclusive to the WAH-64 variant (on the image), demonstrating that they can take off and landing without any problem from different types of ships, despite initial reluctance due to the configuration of the landing gear. This skill was required as a result of the change in British military doctrine. In the late 80s, when the requirements for a new combat helicopter were studied, the large armored formations of the Warsaw Pact were the main threat that the new helicopter would have had to face, but after the collapse of Communism and the Soviet Union, this threat was considered obsolete. From this moment, rapid response and flexibility were considered the essential capabilities of the new military doctrine, and the deployment of a force by land, sea and air was the core of it.The naval capability was demonstrated during their deployment in Operation Ellamy aboard the ship HMS Ocean, within the British military intervention in Libya in 2011. On June 4, 2011, the WAH-64 Apaches (on the image) carried out their first attack mission near the town of Mersa Brega and until their retirement in September 2011, the British Apaches carried out more than 40 successful missions, destroying radar sites, mobile air defenses, tanks, bunkers and vehicles without suffering any casualties. This was the last combat deployment of the WAH-64 Apache, and since then, they have carried out the usual training exercises. From 2020 onwards, all Westland Apaches were progressively retired to be rebuilt to the AH-64E variant, with the last of them being retired on March 25, 2024.In 1995, the Government of the Netherlands placed an order for 30 AH-64Ds, which were delivered between 1998 and 2002. The Dutch Apaches (on the image) have the particularity of carrying the Apache Modular Aircraft Survivability Equipment (AMASE) self-protection system, specially designed against IR missiles. These helicopters have been deployed by the Royal Netherlands Air Force (RNLAF) in different conflicts where they have acted as peacekeeping forces or as part of Multinational forces.Dutch AH-64Ds (on the image) have carried out operations in Djibouti, Bosnia and Herzegovina, Iraq and Afghanistan. In 2004, 6 helicopters joined the Dutch Forces deployed in Iraq within Operation Iraqi Freedom and performed close support and reconnaissance missions. Also in 2004 the Dutch Apaches participated in operations in Afghanistan where one of them was lost when it crashed on August 29 near Kabul. In February 2006 another 6 Apache were deployed with the Dutch contingent within the operations carried out in Afghanistan by NATO Forces. In 2015, another Apache crashed during a training mission in Mali.Like other users, the Netherlands decided to modernize the entire fleet of 28 AH-64Ds (on the image). More specifically, in 2018 it was decided that they would be converted to the AH-64E Apache Guardian standard and 17 APG-78 fire control radar units were acquired. Work will be carried out at Boeing between 2023 and 2025, and the first remanufactured AH-64E v6 helicopter has been delivered to the RNLAF at the end of October 2022.
