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TYPE: Military transport aircraft
COUNTRY OF ORIGIN: Italy
Practical tactical C-27J Spartan: half a Hercules; all airlifter.
Nicknamed "half a Hercules" due to its commonality with the four-engined C-130J, the twin-turboprop C-27J may set the standard for medium tactical airlifters
Based on the Alenia G222 and the C-27A operated by the US Air Force in Central America, the C-27J Spartan represents a significant enhancement of an already capable tactical transport. Offered by the Lockheed Martin Alenia Tactical Transport Systems (LMATTS) joint venture, the C-27J follows the route set by the C-130J in taking a proven design and adding improved avionics and propulsion. Rather than develop unique systems for the Spartan, LMATTS borrowed them from the C-130J. Development time and costs were minimised as proven systems were readily available, and life cycle costs should be reduced as spares commonality with the C-130J ensures a readily available parts pool. The benefits for operators of both the C-130J and C-27J will be even greater, as common avionics and systems will reduce transition-training costs, and may allow for cross-crew qualification.
The C-27J programme was launched in September 1997. The first prototype, used for testing the Rolls-Royce AE2100D2 engines and Dowty R-391 six-blade propellers, flew in September 1999. The second aircraft flew in May 2000, incorporating the new avionics. The third and final development aircraft, representing the baseline model, flew in September 2000. The C-27J received civil certification in June 2001 and military qualification six months later.
With production ramping up for delivery of the first of 12 aircraft to the Greek air force later this year, Flight International was invited to fly the Spartan at Alenia's Turin production and test facility. The Spartan's true strength is apparent on the ramp; it is not a small aircraft. While slightly shorter than its most direct new-build competitor, the EADS Casa C-295, the C-27J has a larger useable cargo volume. The cargo compartment is 2.45m (8ft) wide at its flat floor and 3.33m at it widest point. The large diameter allows a utility vehicle to be driven directly on and off without any modifications or disassembly. The size advantage also carries over to palletised cargo loads. Assuming standard 2.24m-wide pallets, the Spartan can carry 44.1m3 (1,560ft3) of cargo, compared with the C-295's 37.4m3, says LMATTS. These pallets are the same height (2m) as those carried by larger transport aircraft. Pallet compatibility allows cargo to be transferred directly to the Spartan, not broken down and repalletised as may be required for loading into a smaller aircraft. For air-dropped cargo, the C-27J can carry up to 6t of material on a single drop, 9t on multiple runs, while the C-295 is limited to 2t, says LMATTS.
The large cargo compartment also carries dividends when transporting troops. The C-27J can carry up to 68 troops in an optional high-density configuration, based on a 460mm (18in) seat width. For the paradrop mission, the aircraft can carry 46 paratroopers, seven more than the C-295 can reasonably carry, says LMATTS.
The C-27J's large cargo compartment has greater headroom, allowing heavily laden paratroopers to stand erect as they shuffle to the door. The dual exit doors on the C-27J are also larger than those on the C-295 and should allow for rapid exiting of the aircraft. Tactically, the higher the jump cadence the closer the paratroops will be when they hit the ground, thereby increasing combat effectiveness.
The Spartan was developed as a military aircraft and its 17,500kg (38,5001b) operating empty weight is markedly heavier than that of the civil-derived C-295's. The extra weight yields a robust aircraft with a threespar wing. LMATTS says the Spartan's aluminum structure is more damage-tolerant than composites and easier to repair in the field. In addition, military cargo tends to be denser than civil freight, requiring high floor strength. The Spartan's cargo floor has a strength of 5,000kg/m (3,4001b/ft) (along the length of the compartment), superior to the C-295's l,000kg/m and slightly better even than the C-130's, says LMATTS. In addition, the C-27J can carry any cargo further than the C-295: according to LMATTS the Spartan can carry 7,000kg a distance of 3,060km (l,650nm) at its basic and tactical MTOW, while the C-295 can carry the same load over 1,350km.
Pre-flight inspection of the Spartan, the developmental baseline aircraft, was conducted by Alenia test pilot Agostino Frediani. Externally, the aircraft closely resembles the G222 and C-27A, with the exception of the 4.11m-diameter six-blade composite, scimitar-shaped propellers, which are the same as those on the C-130J. The R-R engines put out 4,635shp (3,455kW) and are nearly identical to those on the updated Hercules. When viewed from behind, the propellers turn clockwise, making the critical engine the left one. As the rudder and vertical stabiliser are essentially unchanged from the C-27A, increased rudder power was required to keep minimum control speed at desired levels.
Seventeen vortex generators were added to the left-hand side of the vertical stabiliser just forward of the rudder. These energise the airflow over the rudder, increasing its effectiveness when deflected to counteract yawing moments generated by an engine failure.
Access to the aircraft is through the forward entry door with its integral steps. The flightdeck is quite spacious with 16 windows. Eight shoulder-height windows, four per side, provide an excellent field of view (FoV), while the four floor-level windows gave a direct view of the ground. Four ceiling-mounted windows enhance the overall FOV, while allowing for clearing of the flight path when manoeuvring at high angles of bank.
Like the C-130J, the C-27J's forward instrument panel is dominated by 180 x 205mm (6 x 8in) displays, of which the Spartan has five: two multifunction displays in front of each pilot and one centremounted. Each pilot has primary flight and navigation displays, with the centre screen displaying engine parameters and warning information. Dual autopilots are controlled via a glareshield-mounted panel. Aircraft system controls, mounted on the overhead panels, lend themselves to intuitive operation.
An external-power cart was connected to our aircraft and the dual global-positioning/inertial-navigation units aligned in less than 4min. The Hamilton Sundstrand auxiliary power unit (APU) , mounted in the left landing-gear sponson, provided an air source for engine start. I f the APU is inoperative an external air cart or even another Spartan can be used to start the engines. The engines were started one at a time, the full-authority digital engine control (FADEC) metering fuel to ensure a cool start. Before-taxi check items were rapidly accomplished and consisted primarily of testing the propeller overspeed protection system. Frediani released the parking brake and used the nosewheel steering system's left sidewall-mounted tiller to navigate the taxiways to Turin Caselle's runway 36 for departure.
With an operating empty weight of 18,803kg and 3,606kg of fuel, our take-off weight of 22,409kg was well below the maximum of 30,500kg. Once aligned on the runway, Frediani gave me control of the aircraft for the take-off. I released the toe brakes and advanced the throttles to the take-off detent. The FADECs stabilised the engines at 4,700shp. During the initial part of the take-off roll Frediani used the nosewheel steering to track centreline, while I applied right rudder to counteract the propeller P-factor. At 60kt (llOkm/h) indicated airspeed Frediani released the tiller, and rudder alone was used to track centreline.
At 91kt, less than 15kg of yoke force was required to establish the initial take-off attitude. With the flaps set to position "2" the Spartan leapt of f the runway after a ground run of less than 280m. At maximum take-off weight and standard sea-level conditions, LMATTS quotes a ground run of 580m. Once airborne a pitch attitude approaching 20° was required to maintain the initial climb speed of 130kt. Gear and flap retraction caused little change in pitch forces as the pitch attitude was reduced to capture a climb speed of 170kt.