User:Sp33dyphil/My sandbox 5

Development
In September 1983, Hughes Helicopters handed over to the U.S. Army the first AH-64A Apache. The AH-64A, while considered a formidable attack platform by its operators, was an aircraft with analogue systems. The ineffectiveness of such systems would be demonstrated during Operation Desert Storm in 1991, when Apaches relied heavily on U.S. Air Force MH-53Js equipped with GPS and terrain-following radars for guidance. After the Apache was introduced, McDonnell Douglas began conducting studies aimed at updating the AH-64A. The proposed variant—referred to unofficially as the "AH-64B"—would have had an updated cockpit, a new fire-control system and new and improved armaments. In 1988, the U.S. Army entered directly into AH-64 update studies by allocating $25 million towards a Multi-State Improvement Program (MSIP) for the AH-64 that would allow for the improvement of the helicopter's weapons, sensors and communications systems.

However, with the rapid advancement of technology previously reserved for gradual application on the Apache, it was possible to incorporate all the updates into the helicopter in one go. As a result, the MSIP was shelved before it reached hardware stage, while work continued on the AH-64B proposal before the program too was canceled in 1992. In August 1990, following the cancellation of the MSIP, the US Defense Acquisition Board authorized McDonnell Douglas to embark on a 51-month development phase for the new AH-64D. The schedule was later increased to 70 months to accommodate the development of the AGM-114L Hellfire, the primary weapon of the new variant.

In support of the AH-64D development effort, an AH-64A (serialed 82-3356) was modified by McDonnell Douglas (which had absorbed Hughes Helicopters in 1984) to incorporate the crucial mast-mounted radar housing; the aerodynamic testbed made its maiden flight on 11 March 1991. The first actual AH-64D prototype (serialed 89-0192) performed its first flight on 15 April 1992; by 11 March 1994, five more development aircraft had taken into the air. Meanwhile, development of the radar-guided AGM-114L continued apace, culminating in the first launch in 1993. During the same year, the Symetrics Industries-produced improved data modem transmitted its first air-to-surface communications, marking a major milestone in the effort of updating the Apache to a digital attack helicopter.

In June 1994, the U.S. Army transferred Apache Longbow components—the Longbow radar and uprated engines—from the first prototype to the six (an AH-64D Apache) in four hours, before flying the aircraft for 30 minutes. The final major demonstration prior to the authorization of full-scale production took place from 30 January to 9 February 1995, during which AH-64A/Ds took part in complex gunnery trials at Naval Air Weapons Station China Lake, California. Under simulated conditions, the AH-64D notched 300 kills for 4 losses, compared to 75 kills for 28 losses of the A model. An official remarked: "In all my years of testing, I have never seen a tested system so dominate the system it is intended to replace."

Despite the considerable advancement over the A model, there were technical issues on the AH-64D which needed to be, and were eventually, addressed. It was discovered that the Longbow radar was having difficulty in acquiring stationary targets, while the Hellfire missile was sometimes unable to perform against multiple countermeasures. At the same time, it was believed that the radio system, could be improved.

Following a positive flight test program, on 13 October 1995 US Under Secretary of Defense Paul Kaminsky gave the go ahead for full-scale production of 232 AH-64Ds. Also signed as part of the AH-64D contract was an order for 13,311 AGM-114L missiles, 227 fire-control radars and 3,296 rocket launchers. Deliveries were scheduled to take place from March 1997 to 2008. Within two months of the October 1995 authorization, in December McDonnell Douglas began "remanufacturing" AH-64As into AH-64Ds at its assembly plant in Mesa, Arizona, with the process for each aircraft requiring 15 months. The first production AH-64D flew on 17 March 1997 before being delivered to the U.S. Army on 31 March.

Design
The AH-64D is a derivative of the AH-64A, with which it shares similar external arrangements such as the four-blade main and tail rotors, the tailwheel-type landing gear arrangement. Its two crew members sit in cockpits separated by shielding, such that one crew member can survive hits. Crew members are further protected by sliding seats which lesson the g-load during a 42 ft/sec (12.8 m/sec) vertical descent from 37 g to 13 g. The compartment and the rotor blades are designed to sustain a hit from 23-millimeter (0.91 in) rounds. The airframe includes some 2,500 pounds (1,100 kg) of protection against ballistic strikes. The Apache also utilizes a self-sealing fuel system to protect against the loss of fuel caused by ballistic projectiles.

Operational history
The first AH-64D Apache was delivered to the U.S. Army in March 1997. On 12 June 1998, during a ceremony at Fort Hood in Killeen, Texas, the aircraft officially entered service with the 1st Battalion, 227 Aviation Regiment, 1st Cavalry Division. The AH-64D and its crews underwent the the rest of its eight-month until 9 November 1998, when it was declared operational.