Haruko Ha-7 Akisame (Pacifica)

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Ha-7 Akisame
Role Attack helicopter
National origin  Pelinai
Manufacturer Haruko Project Design Bureau
First flight January 27, 1997; 28 years ago (1997-01-27)
Introduction August 2006 (2006-08)
Status In service
Primary user Pelinai (Pacifica) Pelinese White Army
Produced May 1, 1996 – present (1996-05-01 – present)
Number built 1,900+ (as of 2023)

The Haruko Ha-7 Akisame is a Pelinese twin-turboshaft conventional attack helicopter designed and manufactured by Haruko Project Design Bureau. It was originally designed as a mobile, medium-range heavy ground strike platform for use by the Pelinese White Army, who remains the principal operator with approximately 1,750 airframes in service as of December 2024; other branches of the Pelinese Armed Forces also operate it, though in significantly reduced numbers.

Design

Overview

The Ha-7 Akisame is a conventional-rotor attack helicopter with two turboshaft engines powering a five-bladed main rotor and a four-bladed tail rotor. It carries a pilot and a copilot/gunner (CPG) in a tandem seating arrangement, with the pilot in the front seat and the CPG behind. Landing gear is non-retractable and installed in a conventional arrangement. The fuselage is integrally armored and crashworthy, and features two stub wings carrying the vehicle’s hardpoints.

The Akisame possesses a high degree of resistance to hostile environmental conditions, system failure, and combat damage. The allowable ambient temperature during flight for the Akisame extends from -40°C to +55°C, while the vehicle may also be flown during non-icing inclement weather conditions. A combination of metallic, composite, and ceramic tile armor protects all contents of the fuselage from small arms, fragmentation, and low-caliber cannon fire, with especially strong protection around the crew compartment and main gearbox assembly. Flight-critical systems such as the fly-by-wire system, the engine control units, and segments of the electrical, fuel, & hydraulics systems are extensively redundant and failure-tolerant in case of component failure or combat damage. Automatic fire suppression systems are mounted in both main engines, the auxiliary power unit, and the main gearbox to prevent fires from endangering the aircraft. The Akisame is capable of flying on one turboshaft engine for several minutes after an engine failure, as well as autorotation landing for cases of total shaft power loss. In the event of a ground collision, a combination of energy-absorbing seats and airframe components, strengthened landing gear, and frangible hose connectors help minimize the risk to pilots during impact and reduce the likelihood of post-crash fuel or machine oil fires.

Vehicle systems

The vehicle subsystems of the Akisame include low-level, core structural and functional components such as the airframe, the armor, the electrical, hydraulics, the flight control system, and the pilot support systems. Most of the Akisame’s vehicle systems incorporate high levels of redundancy, backup systems, and/or fault-tolerance capability in order to maintain vehicle operability in the presence of mechanical failures and/or combat damage, with some core systems such as the main flight computer being triple-redundant.

Airframe

The airframe of the Akisame is constructed from a combination of polymer-matrix composites (PMCs) and metals, with the predominant material throughout most of the airframe being fiber-reinforced polymer composites. The inner framing structure, extending across the length of the aircraft in both the fuselage and tail sections, is manufactured primarily from carbon fiber-reinforced epoxy resin due to the lower densities possible with composites and the particularly weight-critical nature of helicopter structures. S-glass reinforced epoxy armor/structure panels are utilized as the airframe’s load-bearing external shell in most areas and are mounted to the internal framing structure primarily with aluminum nut plates bonded using γ-APS primed structural adhesive. Lightweight aluminum alloys are used primarily for fittings such as fasteners and mounting plates for internal systems, while elastomeric bearings are used to isolate sources of mechanical vibration.

The Akisame’s transparent canopy is constructed from a mix of multilayered tempered glass-clad polycarbonate and acrylic glass, with layered glass-polycarbonate being used for the front windshields and acrylic used on the side and overhead panels. The front windshield panels have an integrated anti-icing/fog thin metal film heater system to maintain transparency in inclement weather conditions, while all panels have coatings for protection from solar radiation and 1064mm laser beams. All canopy panels are resistant to small arms fire, with the windshield providing protection against up to 7.62mm caliber rounds; an improved canopy utilizing aluminum oxynitride for effective protection against up to 12.7mm rounds is also in development and testing.

Armor system

The passive armor system of the Ha-7 consists of a combination of integrally armored fuselage panels, ballistic glass canopy panes, and additional reinforcing material around critical areas of the structure. Heavily protected areas such as the main rotor blades, the crew compartment, and the fuselage surrounding the main transmission gearbox are capable of resisting single impacts of up to 25mm cannon fire, while most of the remaining airframe is resistant to single impacts of up to 14.5x114mm tungsten-cored armor piercing rounds.

The main armor composition used throughout the airframe consists of fiber-reinforced epoxy composite panels, which form the majority of the airframe’s external paneling structure and act as an integral armor against impacts of 12.7mm and smaller rounds. The reinforcing fiber used is a woven fabric of high-performance magnesium oxide-rich aluminosilicate S-glass suitable for rigid armor applications. Armoring panels are made as monolithic as possible to minimize joints and seams while remaining consistent with system interface, maintenance access, and other considerations.

Critical areas of the structure receive additional armor protection to maximize survivability and reduce the likelihood of total system disabling by a lucky shot. These measures include both metal reinforcement, such as titanium flooring in the crew compartment, as well as composite-backed boron carbide ceramic armor tiles shielding areas such as the crew compartment and the main rotor gearbox assembly. Further special protective measures include a layered polycarbonate-acrylic transparent shield between the pilot and CPG compartments within the crew compartment, which significantly reduces the ability of single munition impacts to incapacitate both aircraft operators simultaneously.

Electrical systems

The electrical and power distribution system of the Akisame includes the two accessory drive-mounted AC generators on the main turboshaft engines, their associated generator control units, the auxiliary power unit (APU), the emergency ram air turbine, the main power distribution buses, the electricity storage batteries, miscellaneous electrical components such as the aircraft’s lighting systems, and the power distribution wiring.

Electricity generation on the Akisame is made to be highly redundant and survivable due to its heavy usage of electronic and electronic-mediated systems. Each input module connecting one of the two turboshaft engines to the main rotor gearbox is fitted with an AC alternator and a generator control unit on its accessory drive to generate and regulate electric power for engine starters and other systems. Main power generation for avionics, mission equipment, control systems, and other core functions is performed by the Auxiliary Power Unit, which is itself fitted with a hydraulics-based starter. In the event of failure of all normal generator systems, the Akisame also carries a ram air turbine that may be deployed in order to supplement the batteries and provide modest electrical power for core flight-critical systems.

The Ha-7 carries a number of lighting systems for various utility functions, primarily during night operations. Both crew stations incorporate comprehensive green backlighting for visibility of non-display controls during night operations, while formation lights facilitate visibility to nearby friendly helicopters and formation flying in low-visibility conditions. Standard landing lights and navigation lights analogous to those on civilian helicopters are also mounted for utility purposes and usage outside of combat areas. All non-external lighting equipment may be turned on or off from the crew stations as necessary to minimize visibility.

Flight control

The flight control system of the Akisame is fly-by-wire and utilizes electrical impulses sent to and from the pilots’ main side-sticks and other flight controls in order to direct the aircraft and provide feedback to the pilots. Controls are mediated by a triple-redundant main flight computer and backup power supply assembly which translates the desired flight movement into the optimal inputs for the hydraulics system, digital engine controllers, and other flight systems. A stability augmentation system also issues control inputs in order to maintain stability of flight and prevent undesired movement (e.g. adverse yaw in conventional aircraft). When enabled, the autopilot may also control the flight of the helicopter in order to execute the flight plan entered into the flight management system.

Hydraulics

The Akisame utilizes a conventional, centralized hydraulics system for control surface and other actuator control. It is pressurized by two combined pump/reservoir units attached to the main gearbox assembly’s shaft power input modules, as well as several additional AC motor-powered pumps; the reservoirs are additionally air-pressurized using bleed air from the main engines. Hydraulic power is distributed throughout the aircraft with redundant PTFE-lined, stainless steel-braided hydraulic circuits with the exception of some isolated systems such as the tail rotor pitch control piston, which instead utilize self-contained electrohydraulic actuators in order to avoid running multiple hydraulics lines for long distances away from the main system. Commands for the hydraulic system are given by the helicopter flight control computer, which acts on behalf of control impulses issued by pilot inputs, the autopilot, and the stability augmentation system. A hydraulic system-fed starter is also used to initiate operation of the auxiliary power unit.

Like other fluid handling systems such as the fuel and oil systems, the hydraulics system utilizes several components to protect system integrity, contain leaks, and maintain function while impaired by mechanical failure or combat damage. In addition to redundant circuitry, the hydraulics lines running to and from key components are equipped with shutoff valves to prevent fluid leaks through detected circuit breaks.

Pilot support

The Ha-7 carries a variety of pilot support systems for aircrew comfort and protection. A crew compartment air conditioner & heater unit is installed to protect vehicle pilots from extreme temperatures during operations in hot or cold weather, while an overpressure CBRN defense system is also provided for operations in CBRN-contaminated environments. In the event of a downed aircraft, both crew members are supplied with survival kits containing food & water, medicine, basic survival supplies, and an AP-1999 personal defense weapon with ammunition.

Propulsion systems

The propulsion system of the Ha-7 includes most vehicle subsystems pertaining to the generation and usage of shaft power, such as its twin nacelle-mounted Yunimashi VD-94T turboshaft engines, as well as the main helicopter rotor assembly, the tail rotor assembly, the combined gearboxes & power transmission system, and the fuel storage & distribution system. Extensive computerization of control over parameters such as engine spool speed, fuel feed, and rotor RPM in the Akisame allows for benefits including reduced pilot workload and improved flight efficiency while simultaneously removing complex and maintenance-intensive hydromechanical valves and other equipment.

Engines

The main engines of the Ha-7 consist of two Yunimashi VD-94T turboshaft helicopter engines mounted in pods on the upper sides of the central fuselage. The currently used VD-94T2 model of the Ha-7V is rated for a maximum continuous shaft power of 1,254kW at roughly 20,000 RPM, for a total main rotor power of 2,508kW. 30-minute power of each engine amounts to 1,429kW for takeoff, while 3-minute contingency power for emergency situations such as a one-engine inoperative condition is 2,001kW. The high power settings on the engines allows the Akisame to maintain controlled flight even with an engine disabled by mechanical failure or combat damage, substantially improving system reliability and combat survivability. Both engines are fitted with triple-redundant full-authority digital engine control (FADEC) systems that monitor engine conditions and adjust output parameters such as gas generator spool RPM and free spool RPM to obtain flight states commanded by the vehicle operators, as well as automatic engine fire detection and suppression systems.

Fuel system

The fuel system of the Akisame includes its fuel tanks, fuel distribution hoses, fuel pumps, and miscellaneous equipment such as filters, as well as the fuel control units fitted to the main turboshaft engines. It is designed to be extensively redundant, damage tolerant, and crashworthy, with numerous features intended to prevent fuel leakage through severed connections.

The Akisame utilizes four separate self-sealing fuel tanks; each turboshaft engine is nominally designated to receive fuel from two of the four tanks, though fuel can be transported between each side using a transfer pump; the helicopter’s APU is also connected to both sides. Fuel is distributed in self-sealing fuel hoses wrapped in stainless steel braiding. In order to prevent battle or crash damage from creating fuel leaks and fire hazards, the fuel distribution system is interspersed with one-way valves, frangible connectors, and other fixtures that automatically seal damaged connections and stop leakage of fuel.

In order to prevent ice obstruction of fuel filters and other system components, the fuel system of the Ha-7 is equipped with fuel-oil heat exchangers that utilize heat from the transmission to eliminate small ice particles. In the event that ice does accumulate in the filters as detected by a large pressure drop across them, a diagnostic alert will be issued to the crew interface.

Rotor assemblies

The main rotor assembly of the Ha-7 consists of a five-bladed, fully articulated rotor head that receives power directly from the main shaft of the main gearbox assembly inside the fuselage. The helicopter rotor blades themselves are manufactured from fiberglass and carbon fiber-reinforced polymer with a composite main structural spar, while their geometry consists of a high-solidity wide-chord design with blade tip sweep, taper, and anhedral. Blades are attached to the main rotor hub, which also mounts a search and fire control radar system, using a combination of elastomeric and conventional bearings. Rotor parameters such as blade pitch angle and swashplate position are indirectly controlled through control inputs by the pilot, which are converted into movements of the appropriate hydraulic actuators by the fly-by-wire system.

The tail rotor assembly is constructed similarly to the main rotor assembly, though with some features such as the swashplate removed. It is mounted high on the helicopter’s rudder with a powered shaft connecting to the tail rotor gearbox and an added blade pitch control assembly. The tail rotor blades also lack the blade tip features present on the main rotor.

Transmission

The Akisame uses a conventional main gearbox assembly with a lightweight welded, corrosion-resistant stainless steel case and carburized medium alloy steel gears, a lubricant oil circulation system, and additional accessories such as an automated fire detection and suppression system; it is connected to the main engines through two shaft power input modules, which mount the engines’ accessory drives and associated components such as generators and hydraulic system pumps. Both the input modules and the main transmission incorporate sprag clutches in their design as a safety feature, both in order to prevent an inoperative engine from impeding transmission rotation by the other and in order to prevent a wholly inoperative engine and/or transmission assembly from impeding autorotation of the main rotor.

The tail rotor receives power from the main gearbox though a power take-off, which feeds into a tail rotor drive shaft, an intermediate gearbox at the base of the rudder, and a tail gearbox that rotates the shaft outward and connects to the tail rotor assembly itself.

Mission systems

The Akisame utilizes an extensive mission equipment suite including defensive systems, an integrated electronic warfare and ECM/ECCM system, a targeting & fire control system, and a mission data & computing system. The systems together help facilitate operations performed by the Akisame through the augmentation of core mission functions such as survival of the aircraft, identification & targeting of hostile personnel & vehicles, and the reception, storage, and transmission of mission data such as flight plans from and to friendly forces. They also interface extensively with avionics systems such as sensors, navigation equipment, communications, and pilot interface systems.

Defensive subsystems

The Akisame carries an extensive array of defensive systems for enhanced combat survivability, including targeting and sensing identifiers as well as weapon countermeasures. Principal systems include chaff and flare launchers, a laser warning receiver system, a radar warning receiver array, a UV-based missile approach warning system, a directional infrared countermeasures system, and an electronic countermeasures system.

The defensive systems on the Akisame are integrated together into a defense aids subsystem (DASS) that utilizes sensor inputs from defensive equipment, normal vehicle detection and targeting sensors, and the electronic warfare suite to autonomously identify and react to threats to the vehicle. By combining detected radar or laser wave parameters, EW/ECM direction-finding system outputs, and other data and comparing them to a database of known threat platforms, the DASS is able to automatically identify the nature of a detected system, suspected targeting mode (search, track, or active weapon guidance), and approximate location; if enabled, this data will also be automatically added to the digital map display. In the event that an active threat such as a hostile fire control radar lock or an approaching surface-to-air missile is detected, the DASS will sound alarms and can automatically deploy countermeasures such as radar jamming, chaff, and flares, as well as recommend evasive maneuvers.

Electronic warfare

Fire control

Fire control and targeting functions on the Akisame are handled by a combination of the radar, the laser system, and the fire control computer. The Nd-YAG laser mounted on the front ventral sensor turret serves multiple fire control functions, including rangefinding for the 30mm cannon & rockets as well as target designation for laser-guided munitions fired by the helicopter or other friendly platforms; it can also direct laser beam riding weapons. The rotor hub-mounted fire control radar is also capable of providing accurate target range, bearing, and velocity readings to weapon systems. Fire control functions are normally assigned to the copilot/gunner station in the forward area of the crew compartment; however, these controls may be transferred to the pilot station on command.

Mission data and computing

Avionics systems

The Akisame possesses a wide variety of advanced communications, situational awareness, sensor, and other avionics systems not utilized on previous Pelinese rotorcraft. Its core functionality include wide-spectrum radio communication with both nearby units and satellites, station-, satellite-, and INS-based navigation, improved IFF and friendly force tracking capabilities, and an extensively overhauled pilot interface system incorporating multifunction displays, helmet-mounted displays, and other equipment. In order to speed maintenance operations, simplify equipment upgrades, and maximize system availability, avionics systems on the Akisame that cannot be repaired in the field are almost exclusively confined to line-replaceable units that can be removed and replaced quickly. As an additional maintenance aid, a health and usage management system is also installed to monitor the condition of key aircraft components and notify sustainment personnel of needed repairs.

In addition to conventional avionics systems, the Akisame also incorporates a computerized active vibration control system to restrict the propagation of mechanical vibrations throughout the airframe. Operation of the system benefits both comfort of the aircrew and the fatigue life of mechanical components throughout the Akisame.

Communications

The communications suite of the Akisame includes a number of radio-based communication systems covering both voice and data. Standard encrypted radio communications may be performed on the HF, VHF, and UHF bands, as well as on the SHF band for satellite-mediated communication. An ECM-resistant encrypted tactical data link system in the UHF band is also installed to provide capability for rapid transfer of sensor data, friendly & known hostile unit locations, command & control messages, and other tactical information between the Akisame and other Pelinese weapon systems.

Diagnostics

The diagnostics system of the Ha-7 includes all equipment used to detect and, where possible, correct mechanical, electronic, and other system faults; this includes the onboard health and usage monitoring system (HUMS), oil system chip detectors, equipment condition monitoring sensors, and other such devices. The Akisame’s central flight control computer is additionally capable of using the diagnostics system to identify flight events such as damaged fuel/oil lines or a one engine inoperable (OEI) condition and implementing corrective measures.

The health and usage monitoring system utilized by the Ha-7 uses measured vibration, temperature, shaft RPM, time since component installation, and other flight system data to monitor the condition of key components such as the transmission components, the rotor blades, and the engines in order to detect the imminent need for overhaul or replacement of subsystems. Though it is primarily used by maintenance personnel to record relevant data and perform appropriate preventative maintenance, the data and parameters that it records may also be checked in-flight.

Navigation

The Akisame carries a wide variety of air navigation equipment for accurate conformance to flight plans in all environments both with and without radio-silent conditions. An SHF satellite navigation antenna is mounted on the upper side of the fuselage-tail section in order to receive accurate geographical location data from Pelinese navigation satellites. The Akisame is also equipped with the appropriate receiving systems to utilize beacon-based radio navigation, such as an automatic direction finder, a hyperbolic navigation signal receiver, a distance measuring equipment system, and a combination VOR/TACAN system. An inertial navigation system is also mounted, particularly for use in emissions-controlled operations. Other navigational aids provided include a terrain awareness and warning system and a digital map on the pilots’ multifunction displays, along with core flight instrumentation such as radar and barometric altimeters, weather sensors, a compass, and standard aircraft flight parameter instruments. The Akisame is also capable of utilizing ILS and MLS landing aids when available.

Pilot interface

The pilot interface system afforded to each of the Akisame’s two operators consists of a glass cockpit combined with a helmet-mounted display/gunsight system and HOTAS flight controls. Multi-function display (MFD) units are used to display primary flight instrumentation and other flight-critical information, with analog backups also provided for redundancy. The MFDs may also be used to display other sensor, vehicle, and situational awareness information, including topographic & navigation data, autopilot waypoints, electronic warfare & surveillance tracks, locations of friendly & detected hostile systems, weather & search/track radar information, and camera displays from targeting sights.

Sensors

A multifunction sensor suite is mounted on the Akisame to facilitate flight and target detection in all weather conditions, including day, night, and inclement weather. A combined AESA search & fire control radar is mounted on the main rotor mast above the hub; it is capable of tracking up to 144 terrestrial, maritime surface, and aerial targets while engaging up to 18 of them. An inverted sensor turret on the nose of the helicopter also provides a combined FLIR & color TV camera system for observation and targeting capability: the FLIR component utilizes a combined MWIR/LWIR system with 50°x50° FOV on the WFOV sensor, 10°x10° FOV on the MFOV sensor, and 3°x3° on the NFOV sensor, while the color television camera provides 4°x4° FOV on the WFOV sensor and 1.0°x1.0° on the NFOV sensor. A Nd:YAG laser rangefinder and target designator is also installed to the right of the TV cameras. In addition to the inverted turret, an upright turret mounted above it possesses an infrared camera for the pilot night vision system. One or both turrets may be linked to the orientation of the operator’s helmet such that they match the operator’s direction of view.

Armament system

The armament system of the Akisame consists of an integral 30mm autocannon turret, the stub wing hardpoints, and associated equipment such as the weapons management system. As an attack helicopter with primary roles in close air support and anti-armor operations, the Akisame’s primary armament consists of an autocannon, unguided ground attack rockets, and anti-tank guided missiles, as well as a limited number of short-range surface-to-air missiles for self-defense against hostile helicopters and low-flying aircraft; additional equipment compatible with the vehicle’s four underwing hardpoints includes drop tanks, gun pods, and small unguided bombs.

Autocannon

The autocannon subsystem on the Akisame includes the FHE N30L 30x113mmB autocannon, its traversal equipment, and the ammunition storage & feed system; all of these are mounted on the forward ventral side of the helicopter under the crew compartment. The autocannon is intended for ground support fire roles against both dismounted infantry and armored vehicles, with a maximum elevation of 12° and a maximum depression of 58°. Control of the autocannon system is normally assigned to the copilot/gunner station, but may be transferred to the pilot station as with other system controls; the current gun operator may also link the turret’s traverse to their flight helmet and aim it through movement of the head.

The ammunition storage & feed assembly holds a maximum of 1,000 30x113mmB autocannon rounds for the ventral autocannon. Ammunition types normally loaded onto the Akisame include high explosive, armor piercing incendiary, and armor piercing incendiary tracer; other 30x113mmB ammunition types can, however, be loaded as long as they are compatible with the N30L.

Weapons interface

The Akisame’s weapons interface system includes four underwing weapons stations and two wingtip stations, which allow it to carry and launch equipment such as munitions and drop tanks. The two stations nearest to the fuselage contain fuel transfer equipment, allowing for the mounting of drop tanks, while the two wingtip stations are reserved for dual Z28A/2 Jasper IR-guided anti-aircraft missiles.

Weapons management

Operational history

Variants

Operators

Pelinai (Pacifica)Pelinai
  • The Pelinese White Army possesses 1,743 total Ha-7 airframes in active service as of December 2024.

Specifications (Ha-7V)

General characteristics

  • Crew: 2 (pilot and copilot/gunner)
  • Length: 16.9 m (55 ft 5 in)
  • Wingspan: 12.8 m (42 ft 0 in)
  • Height: 4.2 m (13 ft 9 in)
  • Empty weight: 4,800 kg (10,582 lb)
  • Gross weight: 7,400 kg (16,314 lb)
  • Max takeoff weight: 10,100 kg (22,267 lb)
  • Fuel capacity: roughly 2,400kg internally
  • Powerplant: 2 × Yunimashi VD-94T turboshaft engines, 1,251 kW (1,678 hp) each
  • Main rotor diameter: 13.6 m (44 ft 7 in)
  • Main rotor area: 145.3 m2 (1,564 sq ft)

Performance

  • Maximum speed: 320 km/h (200 mph, 170 kn)
  • Cruise speed: 280 km/h (170 mph, 150 kn)
  • Range: 900 km (560 mi, 490 nmi)
  • Combat range: 400 km (250 mi, 220 nmi)
  • Service ceiling: 7,000 m (23,000 ft)
  • Disk loading: 50.9 kg/m2 (10.4 lb/sq ft)

Armament

  • Guns: 1 x N30L 30x113mmB turreted autocannon, 1000 rounds
  • Hardpoints: 4 x standard hardpoints, 2 wingtip hardpoints with provisions to carry combinations of:

Avionics

Sensors & targeting systems:

Defensive systems:

Communications & Network Interface systems:

Pilot support systems:

See also

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