Like most Knootian military designs currently in use, the ZP range of helicopters saw the light in the late 1980s and was brought into service when budgets grew during the mid-to-late 1990s. While the Landmacht and Marine had been importing foreign designs for use on frigates and in army aviation (a practice which continues to this date for certain niche roles), it had never fielded a domestically built attack helicopter. After the invasion of Hague by GDODAD and the conclusion of that war it was deemed important to promote the domestic arms manufacturing industry by fielding designs tailored to Knootian circumstances and doctrines. The newly expanded army aviation department was one of the recipients of funds being made available for this purpose, and designs were soon being floated by the Knootian military-industrial complex.
A tender for an advanced attack helicopter was won by a joint venture holding group spearheaded by Euro Corp, which also developed the KDF80 Vuurhaag Interceptor. The development process was plagued by changing political requirements and slow feature creep, resulting in vast differences between the original ZP1-NX Prototype and its contemporary variants. The prototype was a small (~10 meters diameter) single seat stealth helicopter with a fenestron tail rotor that could scout out enemy positions and provide low-level combat air support to friendly infantry. Successive upgrades to the helicopters' armament required an increase in the size of the fuselage so that it could hold an expanded internal missile bay. When it was finally brought into production, the resulting ZP2-VA Attack Helicopter looked a little more more like the gunships that are common in today's armed forces, though its coaxial rotor design, aerobatic qualities and relative stealth set it apart from the herd.
During 2007-2008, budget overruns in the Army Aviation budget (caused, ironically, by the development of the ZP-series) caused the cancellation of a tender for a dedicated helicopter to conduct battlefield reconnaissance and provide target designation for the new CAESAR system. The decision was made to upgrade the ZP4-VA with better optics so that it could perform in this role, prompting the development of the ZP5-VA. This refit saw the integration of forward-looking infrared (FLIR), low-light, and remote-camera imaging in a quadriple-redundant optics tower atop its mast, as well as addition of the CLOWN system, which was again improved in 2015 by the addition of a laser with offensive capabilities as a tertiary weapon. Now enhanced with look-over capability and superior optics, the ZP5-VA is an integrative part of the CAESAR Battlefield Management System, capable of spotting targets and relaying the data back to ground forces and artillery in real time. The increased complexity required the addition a second crew member, prompting the developers to use the same side-by-side seating arrangement that had already been implemented in the ZP4-T Trainer craft. Due to the helicopters' relatively narrow profile there is very little space between the seats, necessitating the repositioning of the back supports into a horizontal position to more easily reach the cabin exit behind the forward compartment.
An extensive range of military sensors has been fitted onto the platform, including forward-looking infrared (FLIR), low-light, and remote-camera imaging, as well as terrain-following radar. Hidden digital camera's have been dispersed throughout the hull, allowing the pilot/gunner to 'see through' the hull using the HUD in all directions using an integrated helmet design, with the option of using the rotating day/night IIR system and a night time light intensifying system.
A Battlefield Management and Navigation computer is installed, allowing interface with the national CAESAR Battlefield Management System. In addition to the LCD multi-functional displays common to a 21st century glass cockpit, there are contact points the crew's PDA's, allowing en-route charging and networking capabilities. CAESAR allows the on-board displays to display and network accurate real-time information not only of friendly forces, but also of hostile forces, terrain conditions and more.
The RAH-66 'Pete' is armed with a LAGA-30 30 mm automatic cannon under its nose. This versatile and accurate weapon is able to serve both an air-to-air and air-to-ground role and is able to hold 300 high-fragmentation, explosive incendiary, or DU armour-piercing rounds rounds of ammunition, each of which are fed separately to the gun and may be selected during the flight. The free-firing turret allows an aiming range of +15° to -45° in elevation and ±120° azimuth. It may be stored at +2° in elevation and 180° azimuth in order to reduce radar cross-section.
The helicopter foregoes external Hard Points on stub wings in favour of an internal bay that is serviced by an extendible missile cradle. While this limits the number of missiles that it can carry, it greatly reduces the profile of the unit and allows it to retain its angular profile. The bay can hold 6× Peil SACLOS ATGM air-to-ground missiles or 12× Spreeuw air-to-air missiles, depending on the mission profile.
Finally, there is CLOWN, a High-Energy Spectral Beam Combined Fiber Laser System (HEFL) that uses proprietary adaptive optical components and to deliver a high-energy laser weapon system (HELWS) with 30 kW of power. Operating in a narrow band of the short wave infrared, the process is not unlike a rainbow being combined into a single beam of white light by a grating or prism, bringing together the output of many fiber lasers using an optical grating. The modules are operating at closely spaced wavelengths and combine with little loss, creating a very bright spatially coherent beam. This provides a cost effective directed energy capability that has offensive capability against low-end asymmetric threats such as man-portable air-defence systems, especially in target rich environments. The globe-shaped delivery system at the front of the nose is capable of engaging targets at all angles bar those directly behind the helicopter.
Twin PK5066 Turboshaft engines provide 1,900 hp or 1,416 kilowatt of power each. These gas turbine engines produce shaft power, rather than jet thrust. The turboshaft engine is in turn connected to the rotors via shafts and gearboxes, which provides all motive power for the helicopter. The Pete features a contra-rotating co-axial rotor system, which removes the need for the entire tail rotor assembly (saving up to 30% of engine power) and improves the aircraft's aerobatic qualities—it can perform loops, rolls and "the funnel" (circle-strafing), where the aircraft maintains a line-of-sight to the target while flying circles of varying altitude, elevation and airspeed around it. Since the speed of the advancing rotor tip is a primary limitation to the maximum speed of a helicopter, this allows a faster maximum speed.
The coaxial rotor design provides a hovering ceiling of 5,500 meters and vertical rate of climb of 11 meters per second (2,165 feet per minute). The rotor blades are made from composite materials to reduce their acoustic signature. The coaxial-rotor configuration results in moments of inertia values relative to vertical and lateral axes between 1.5 to two times less than the values found in single-rotor helicopters with tail rotors. Absence of the tail rotor enables the helicopter to perform flat turns within the entire flight speed range. A maximum vertical load factor of 3.5 g combined with low moments of inertia give it a high level of agility.
While not a 'pure' stealth helicopter, the 'Pete' incorporates multiple techniques to reduce its acoustic signature, radar cross-section (RCS) and infrared heat emissions. The coaxial set-up and composite materials of the rotor significantly reduce the amount of noise associated with the approach of the helicopter and a relatively quiet engine enhances this feature, making its acoustic signature significantly lower than that of comparative helicopters. The entire craft has radar-absorbent material (RAM) coatings and infrared-suppressant paint applied.
Extensive all-round composite armour and armoured glass installed around the cockpit protect the pilot against armour-piercing bullets and projectile fragments and the rotor blades are rated to withstand several hits of ground-based automatic weapons. Additional protection has been built around critical systems such as the fuel tanks, controls, drive system and hydraulics.
To counter incoming threats, it is fitted with a radar warning receiver, electronic warfare system and chaff and flare dispenser. The dispensers are placed at the sides of the fuselage. Each casing (container) contains two dispensers with 32 x 26 mm countermeasures each. The whole system works on principle of evaluated response based on infrared or electronic impulse irradiation.
Due to the superior flight control, retractable wheeled landing gear and relatively compact design of the helicopter, navalisation is a relatively straightforward matter. A naval variant dubbed the ZP5-S is essentially the same unit, but it features folding rotor blades and special anti-corrosion treatment. In this role it is able to fire a pair of passive infrared or radar-guided Nimrod-28 Anti Ship Missiles, which have an operational range of 60 kilometres (37 miles) and are programmed to be able to perform random weaving manoeuvres at target approach, while attempting to strike the target close to the waterline.
ZP5-VA 'Pete' Attack Helicopter
9,42 meters (fuselage)
3,11 meters (excluding rotors and optics)
5,061 kilogram empty
2 x PK5066 Turboshaft engines (1,900 hp, 1,416 kilowatt each)
Twin 5-bladed coaxial rotors
165 knots (306 kilometres per hour) cruise speed
582 kilometres (314 nautical miles) on internal fuel
5,500 meters (18,000 feet)
Rate of climb
11 meters per second (2,165 feet per minute)
LAGA-30 30 mm automatic cannon
2x Nimrod-28 Heavy Anti Ship Missiles OR
CLOWN 30 kW High-Energy Spectral Beam Combined Fiber Laser System