Hkp.22 Alligator The
Hkp.22 Alligator is a large helicopter gunship and attack helicopter that is produced by the Karolinistad Aircraft Corporation, Ltd, for the Royal Cottish Army and the Royal Cottish Navy. The
Alligator serves as the principal attack helicopter gunship in the anti-tank and close air support roles for the Royal Cottish Armed Forces, and is particularly well liked by the Cottish special operations community due to its large weapons load and the low-capacity troop compartment, which enables the
Alligator to carry up to eight troops.
DesignThe design of the
Alligator is dominated by the two top-mounted turboshaft engines driving a mid-mounted 17.3 m five-blade main rotor and a three-blade tail rotor. The engine configuration gave the aircraft its distinctive double air intake. Original versions have an angular greenhouse-style cockpit; Model D and later have a characteristic tandem cockpit with a "double bubble" canopy. Two mid-mounted stub wings provide weapon hardpoints, each offering three stations, in addition to providing lift. The load-out mix is mission dependent; The
Alligator can be tasked with close air support, anti-tank operations, or aerial combat.
The body is heavily armored and can resist impacts from .50 caliber (12.7 mm) rounds from all angles, including the titanium rotor blades. The cockpit is an even more heavily armored titanium tub and can resist impact from 35mm cannon rounds. The cockpit and crew compartment are overpressurized to protect the crew in NBC conditions.
Considerable attention was given to making the
Alligator fast. The airframe was streamlined, and fitted with retractable tricycle undercarriage landing gear to reduce drag. The wings provide considerable lift at high speed, up to a quarter of total lift. The main rotor was tilted 2.5° to the right from the fuselage to counteract dissymmetry of lift at high speed and provide a more stable firing platform. The landing gear was also tilted to the left so the rotor would still be level when the aircraft was on the ground, making the rest of the airframe tilt to the left. The tail was also asymmetrical to give a side force at speed, thus unloading the tail rotor.
ArmamentThe armament given to the
Alligator clearly illustrates the intended main roles. No less than four artillery-type weapons are mounted on the
Alligator, allowing the aircraft to lay large amounts of firepower onto the enemy and support the troops on the ground.
The principal artillery armament for use against structures, tanks and armoured vehicles, and other ground targets is the LK.30142, a single-barrel automatic chain gun which fires the 30x173MM round of GAU-8 Avenger fame. Typical ammunition loadout consists of 500 rounds, with a even mix of PGU-14 Armoured-Piercing Incendiary and PGU-13 High-Explosive Incendiary rounds. The LK.30142 is mounted in a flexibly-mounted turret underneath the gunner, and uses a 2 hp electric motor to load the 30MM ammunition at a rate of roughly 600 rounds per minute. The practical rate of fire is roughly 300 rounds per minute, with a ten-minute cooling period due to the cannon being air cooled. The gun has a positive cook-off safety for open bolt clearing, and double ram prevention. Spent casings are ejected overboard through the bottom of the gun. The LK.30142 has an effective range of 1,600 meters, and a maximum range of 4,500 meters.
Secondary artillery armament for anti-personnel use is the Layartebian-made M79A1 three-barrel automatic Gatling-type chain gun, which fires the 12.7x99MM round. The M79A1 is mounted in the nose, and is controlled by the Gunner. A total of 3,000 rounds of ammunition is carried at the ready for the M79A1 in a linkless belt.
The designers at Karolinistad didn't neglect the passengers, who were allocated two MG3 medium machine guns mounted in the side windows, allowing the passengers and/or the Crew Chief to lay down covering fire and assist the Gunner in the anti-personnel role. The MG3 is an automatic, air-cooled, belt-fed short recoil-operated machine gun chambered for the 7.62x51MM round, modified for the helicopter-mounted role with a casing catcher which directs the spent ejected casings down out from the helicopter, so that the casings aren't thrown upwards into the rotor or engine air intakes, something which could potentially be catastrophic. 3,000 rounds in a linkless belt are carried for each of the two MG3s.
Principal rocket-armament consists of six hardpoints mounted on the side wings (3 on each hardpoint), plus two wingtip hardpoints which can carry lightweight air to air missiles. All six hardpoints are rated to carry up to 500 kg each (allowing them to carry up to four anti-tank missiles or one rocket pod per hardpoint each), while the two wingtip hardpoints are rated at 80 kg each (allowing them to carry up to two air-to-air missiles each). This allows the
Alligator to carry a theoretical maximum load of twenty-four anti-tank missiles and two air to air missiles. The anti-tank missiles are fed target data from the
Armbrøst millimetric-wave fire-control radar, which is based on the Longbow millimetric-wave radar, mounted above the rotor assembly. This allows the
Alligator to remain hidden behind an obstacle, and still detect and engage targets up to 12 kilometers away, and track 144 targets simultaneously and prioritize the top 24 threats.
A textbook "ambush" scenario would see an
Alligator section move into position masked by terrain and coordinating via datalink. The lead ship would then raise its
Armbrøst system to detect targets, and then drop back under cover, while the lead gunner distributes the targets via "drag and drop" to the other aircraft in the group, to avoid multiple targeting. At that point, all aircraft can salvo launch their anti-tank missiles and back out into a new position, while the missiles attack the targets. The software "remembers" the coordinates of attacked targets and flags these on the screen with an X to avoid redundant reattack and wasting of rounds.
General characteristicsCrew: 3 (Pilot, Gunner, Crew Chief/Side Gunner)
Passenger: Up to 8 dismounts, or up to 4 strechers
Fuselage Length: 16.8 m
Rotor Diameter: 17.3 m
Disc Diameter: 235 m2
Fuselage Height: 2.5 m (fuselage); 6.5 m (wheels to rotor assembly)
Fuselage Width: 2.45 m
Weight (Empty): 7,900 kg
Weight (Loaded): 10,500 kg
Weight (Max Take-Off): 12,100 kg
Weight (Internal Fuel): 1,900 kg
Weight (Max Munitions): 2,800 kg
Powerplant: Two Karolinistad KMTS-242M gas turbine turboshaft engines
Thrust: 4,600 hp (2,300 hp per turbine)
PreformanceMax Speed: 350 kph
Cruise Speed: 320 kph
Combat Radius: 450 km
Ferry Radius: 1,600 km
Service Ceiling: 4,000 m
Max Ceiling: 4,500 m
Thrust/Weight Ratio: 403.5 hp/ton (Loaded); 380.1 hp/ton (Max Take-Off); 582.2 hp/ton (Empty)
ArmamentCannon: - One flexibly-mounted Kongsberg LK.30142 30x173MM single-barrel automatic chain gun with 500 rounds ready
- One nose-mounted LDC M79A1 12.7x99MM three-barrel automatic Gatling-type chain gun with 3,000 rounds ready
- Two Rheinmetal MG3 7.62x51MM passenger compartment window-mounted machine guns with 2,000 rounds ready per gun
Internal Hardpoints: None
External Hardpoints: - Two inner wing-mounted hardpoints, rated at 500 kg each (four Hellfire/Brimstone/equivalent anti-tank missiles or one 19-round CRV7 70MM rocket pod/equivalent per hardpoint)
- Two center wing-mounted hardpoints, rated at 500 kg each (four Hellfire/Brimstone/equivalent anti-tank missiles or one 19-round CRV7 70MM rocket pod/equivalent per hardpoint)
- Two outer wing-mounted hardpoints, rated at 500 kg each (four Hellfire/Brimstone/equivalent anti-tank missiles or one 19-round CRV7 70MM rocket pod/equivalent per hardpoint)
- Two wingtip hardpoints, rated at 80 kg each (one AIM-186 Wizard air-to-air missile per hardpoint)
OtherAvionics: - Armbrøst Fire-Control Radar
- IFAS-55F Integrated Flight Avionics System
- Mk.553H Helicopter-Mounted Radar Warning Receiver
- Mk.555 Helicopter-Mounted Laser Warning Receiver
- Thermal Imaging Forward-Looking Sensors
Chaff: 90
Flares: 120
Cost: $24,000,000
Variants: