Harry Hopkins/NAPLES
THE ALENIA G222 is among the few 5-10t-payload loading-ramp-equipped transports, which are still in production. The others are largely Antonov designs or Chinese-made equivalents, although the Airtech (CASA/IPTN) CN-235 has a 6t payload. We evaluated the G222, dating from the 1970s, because of renewed interest in a short take-off and landing fixed-wing transport with a longer range than that of helicopters.
Alenia's C-27A Spartan version of the G222 is now being used by the US Air Force at its Panama base. The only similar aircraft in the past inventory of the USAF dates back to the 1960s, and the piston-engine Fairchild C-123.
Alenia calls the G222 an "assault aircraft", but it is unmistakably a multi-role military transport. Its cockpit has windows ahead, above and below. The high wing has an aspect ratio of 10:1, while the tail-plane, fin and rudder are large, as expected, on a relatively short fuselage.
The body-mounted tandem undercarriage tracks 3.67m, with a wheel base of 6.23m from its mid point to the dual-tyre nosegear
The General Electric T64/P4D engine, made under licence by FiatAvio, is derived from the turbo-shaft used in the Sikorsky CH/MH-53E Super Stallion and Sea Dragon helicopters. Where the T64-GE-419 turbo-shaft delivers 3,540kW (4,750hp), however, the P4D turboprop is flat rated at 2,535kW to 45°C at sea-level, driving 4.42m-diameter, three-bladed, Hamilton Standard propellers.
Systems servicing and single-point refueling is from the right gear sponson - a complete refueling takes 15min. The exhaust for the 113kW AlliedSignal auxiliary power unit (APU) in the left sponson exits low down, pointing outwards and to the rear - not too convenient for those working near it on the ground. The APU does have a convenient air-off-take for pneumatic tools and equipment, however.
At Alenia's Naples base, senior test pilot "Freddy" Freddiani, showed me round the upgraded prototype. As he did so, he pointed out a great strength of the G222 - its load handling and dropping system, specified by the Italian air force to be common with that of the C-130 (see specification box, P32).
The load area is flexible in layout. Canvas bench seats for troop carrying, are folded up against the side-walls, clear of the loading area. When they are swung down, legs drop from their forward edges to fix easily into floor slots. The load area's cross-section, 2.45m wide and 2.25m high, has a diagonal of 3.32m - giving a 50mm margin for carrying a G222 propeller with its three blades optimally angled. A pressure differential of 0.4 bar (6lb/in2) gives a 4,000ft (1,220m) cabin-pressure altitude at 20,000ft and 6,700ft at the normal 25,000ft ceiling. (The maximum operating ceiling is 30,000ft, with a single-engine ceiling of 11,200ft at maximum weight.)
Three steps up to the cockpit are formed in the rear of its under-floor bulkhead. A wide gap between the seats and centre console is easily negotiated by, a pilot wearing bulky clothing and equipment. Handgrips are located above both sides of each windscreen.
Seat tracking is mechanical - separate levers, left and right, control sideways or fore/aft lock releases. The Ipeco seats can be adjusted easily, and are comfortable. A good all-round view is enhanced by the presence of large opening windows on each side. The roof has one escape hatch; two more in the load area are handy for providing access to the upper wing.
Most controls are easy to reach: the rudder-pedal adjuster is just below the instrument panel, but the windscreen-wiper control alongside it is awkward.
Each pilot, has a pair of power levers, with the fuel and propeller levers between them. The lift-dumper switch and the multi-gated flap and gear levers are handily placed for either pilot on the vertical face behind the power levers, as are the landing-light switches to their right.
The instrument layout is functional, under a deep, well-shaped, glare-shield. Electro-mechanical instrumentation is married with "state-of-the art conventional" avionics, including a single inertial-navigation system and Omega receivers. Alenia has completed studies for the installation of an electronic flight-instrument system, should a customer call for it.
The simple, but clear, primary engine gauges are in two columns, left of centre, with secondary ones alongside. As on Rolls-Royce Dart- and Tyne-powered aircraft, the torque gauges are 50% larger than the others.
Several warning lights are spread along the edge of the glare-shields, while "military" controls - for door monitoring, cabin warning and signaling - are sensibly separated on eyebrow panels above the windscreens. The main warning-annunciator panel, right of centre, is full and has a small extension panel.
Auto flight warning and comparator lights unusually set down between the two separate flight-mode controllers on the console, are only just within the pilots' peripheral vision. The audio-control units on the side-walls, are also inconveniently far back.
IN THE COCKPIT
Chief test pilot Luca Evangelini took the jump seat behind, to monitor the flight and take notes. The APU quickly cooled the cockpit from an outside 28¡C. Pleated blinds over the two pairs of overhead windows protect the cockpit from the sun and allow the pilots a clear view of the overhead panel between them. This panel is horizontal, as in the British Aerospace/ Aerospatiale Concorde, so the pilots have to lean back to see the displays and controls, and the electrical-system sub-panel is uncomfortably far back. There are three 45kVA alternators (one driven by each engine, and one by the APU) which provide adequate redundancy, as all the demands of the aircraft can be met by one. A static inverter supplies standby and emergency AC Electric.
Two hydraulic systems power the gear, brakes and steering, flaps, rudder, lift spoilers and ramp. An auxiliary electric pump, powered by the APU, covers essential services should both main pumps fail. The APU can be started at up to 25,000ft and run at altitudes of up to 30,000ft. It generates ample air for starting: external or cross-bled air from a running engine can also be used. Air-starts take about 1min in cold conditions, or an engine can be re-lit with the propeller wind milling.
Each fuel-condition lever was unlocked and moved into "ground idle" at 20% Ng (gas generator speed) by sliding an unfamiliar cuff along it. The starter cuts out at 50% Ng, leaving the engine to reach idle in 35s (the stopwatch is nicely placed in the control-hand-wheel boss).
With condition levers at "flight idle" Ng increased by 7% to 72%: torque (Tq) was 100lb/ft (74Nm), propeller speed (Np) 40%, turbine inlet temperature (TIT) 470°C, and fuel flow 135kg/h (300lb/h) per engine.
The parking brake lever (a rod with a yellow handled twist release) moves down easily. Emergency braking is selected by a similar handle. The brake pedal angle and foot-force gradient, allow a smooth progression from light to heavy braking. If the aircraft is landed with the foot brakes on, they work only after the wheels have spun up. Their high capacity means that just 15min of cooling are needed after a stop from 100kt (185km/h) at maximum landing weight, and about 5min if braking is delayed until 90kt.
Maximum take-off weight is 28,000kg, and full fuel load is 9,400kg. The test aircraft was light - 21,240kg, including 5,500kg fuel, so taxiing at normal idle was lively. A propeller pitch-stop switch, which introduces a finer blade-angle allowing Np to rise from 40% to 58%, is on the roof panel. It might be better located on a power lever. Rapid slowing in this mode at light-weight, meant frequent switching back and forth to normal ground mode.
The electro-hydraulic steering tiller, on the left side only, has an engagement trigger on its forward face and radio-transmit switch at the top. Oddly shaped, like an upturned golf club with a metal head angled up and forward, it lies at arm's length. I found the aircraft wandering until I lowered the left armrest to use as an elbow pivot.
Flap was selected to its mid-position of 22°, ready for a "tactical" take-off which involves maximum power and rapid rotation at well below normal speed, and which saves 100m in take-off distance. Even at maximum take-off weight of 28,000kg, however, normal rotate and lift-off speeds are low at 92-99kt (170-185km/h).
TAKE-OFF
I lined up on runway 24, holding the brakes briefly as Freddiani fed in power to reach 108% Np and 1,075ft/lb (790Nm) Tq. Fuel-flow per engine was 730kg/h: at full single-engine power it is more than 900kg/h. As I released the brakes, the acceleration was extremely rapid. Having rapidly transferred to rudder steering at 40-50kt, I pulled back on the stick 4s later - at a mere 80kt. With the centre of gravity in the middle of its range, the pitch trim was set to balance the stick load at low lift-off speed. This was 87kt - only 10% above power-on stall speed, which is also, the minimum control speed with full 960Nm Tq on a single engine. The stall speed is up to 14kt higher at idle power, without the extra lift from the propeller wash over the wing.
Rotation at over 3°/s quickly set up an attitude of 10°: as all was well, I continued to 15°, to hold the airspeed at around 110kt until we accelerated to the flaps-up climb speed of 132kt. With two-engine power in standard conditions, the rate of climb, even at maximum take-off weight, is 1,250ft/min (6.3m/s), so the correct functioning of the pressurisation system is quickly checked. On take-off from rough fields, it is left off until airborne to avoid ingestion of dust.
Flap retraction pitched the nose up slightly: it fell again as the power was reduced to 100% Np, but I had to trim forward quickly as the airspeed increased to 160kt for route climb.
Pitch trim needs to be rapid and powerful on the G222 - after only 3s trimming away from the balanced setting, I could no longer comfortably hold nose-heaviness. In contrast, extreme lateral trim is benign and to overcome full trim in either direction does not require an excessive foot load. Trim offsets can be quickly checked on large gauges ahead of the fuel panel.
Reaction to a sudden push on the control column was damped out immediately. After trimming the aircraft neutral at 185kt, I slowed it to 160kt with back-stick pressure and released the controls: the resulting phugoid motion on a 70s cycle gave a peak airspeed of 207kt, but it was rapidly damped back to the trimmed value. Dual elevator control runs with disconnection handles are fitted to production aircraft.
At 190kt, lateral balance (spiral stability), is neutral in a 30° banked turn and the roll rate is a respectable 15°/s. An even more rapid evasive manoeuvre was tried by kicking in rudder on rolling, with no untoward effects.
Entering a turn on rudder alone, with the control wheel free, confirmed the lack of adverse yaw on entry - there was just a pause before the bank increased in response. Dutch roll was languid and flat, and was reduced to half the initial amplitude in a couple of seconds.
The G222 could be held level in steep turns to 55° bank, but it quickly becomes difficult to maintain altitude at greater angles.
MANUAL CONTROLS
Overall, the manual controls (only the rudder, spoilers and flaps are powered, but ailerons and elevators have servo-tabs) are effective and well suited to low level manoeuvring in terrain. The available engine power is determined by TIT. From 10,000ft to 20,000ft, the TIT remained a constant 75°C - the military setting. Maximum continuous power is delivered at 720°C and maximum emergency power at 775°C.
In a 160kt climb, Tq decreased steadily from 715Nm to 560Nm and fuel-flow per engine from 600kg/h to 475kg/h in International Standard Atmosphere (ISA) +15° conditions. Climb rate varied little from 1,400ft/min (7.1m/s), with the nose up at a steep 8°. The G222's Vmo decreases linearly from 240kt at 10,000ft to 185kt at 30,000ft: our airspeed was reduced to 140kt for the final climb to 25,000ft, but this was with the aircraft at nearly 10° nose-up. Dutch roll was slightly less well dampened at this speed and altitude, but not so much as to require the yaw damper.
Annunciations for the single autopilot, dual flight director and navigation systems are spread about between the glare-shield and the artificial horizon. The modes for the autopilot are simple, with vertical speed and airspeed holds on the captain's mode selector only. There is no altitude capture; but a held altitude is kept in the memory should the autopilot be disconnected.
The fuel-system panel is well laid out ahead of the engine controls. Fuel can be jettisoned at a rate of 260kg/min; the same pumps are used when the G222 is used as an air-to-air refueling tanker, including for helicopters.
With 45min holding reserves, the range with maximum payload is 1,150km and 2,800km with a 6t payload. Ferry range with full fuel and a 2t payload is 5,000km.
At 100% Np, vibration from the three-bladed propellers had been intrusive, but it is much less so with Np reduced to 87.5%. In cruise, at 166kt (250kt true airspeed), the engine data were, Tq 520Nm, TIT 710°, Ng 91.5% and fuel flow 385kg/h each engine. The attitude was still 4° nose-up.
In steep turns above 50¡ bank, the aircraft showed a slight tendency to bank further without additional control-wheel force. The aircraft was dived with power on to Vmo - 200kt at 24,000ft. The controls felt no stiffer, and the roll rate was still high. With power at "idle", we made a simulated emergency descent at 4,000ft/min, with the nose 11° down and the aircraft clean. In an alternative emergency descent, at 120kt with the gear down and 45° (full) flap, the aircraft reached a 15° nose-down attitude.
The G222 can descend steeply over close terrain. The propeller low-pitch stop can be set in flight to an approach setting, half-way between the flight and ground stops. Using this option demonstrated that the stop reminder lights, also on the overhead panel, might be better located.
HIGH-WING STALL
As I began to investigate the stalling characteristics, I was pleased to note that an angle-of-attack gauge is a standard fitting. The stall warning operated at 10% above the stalling speed when clean or in the landing configuration, and at 6% above stalling speed with mid-flap. As on smaller high-wing aircraft, the descent rate increases as the stall is approached with the column fully rearwards - but under full lateral control, with the nose slightly down in light buffet.
Recoveries were made flapless; with mid-flap; and in the final landing configuration. The greatest height loss during a recovery was 1,000ft, clean and without prompt addition of power; and the least less than 400ft with full flap and instant power-up.
All the recoveries were made conventionally, by positively lowering the nose to regain airspeed. As it quickly restores airflow over much of the wing, increasing the power during recovery means that less nose-down pitch is required to restore speed.
Sustained sideslip with full rudder was possible at up to 12¡ bank, after which the wings insisted on rolling back more level. There is no tendency at all for the controls to loosen up during these manoeuvres.
To cope with a sudden engine-cut at 90kt, in a full-power climb with mid-flap, we needed the permitted 5¡ wing down into the live engine, as well as full rudder against it; without this, the heading can begin to change rapidly. The airspeed momentarily reached 86kt as I lowered the nose, and the stick-shaker was operating, so the controllability was creditable.
Three circuits were made at a nearby military field: standard, steep and steep close in. The view over the nose is good on final descent. At 25-30° bank, the side window-frame interferes with vision: to look inside the turn, the pilot needs either to bend down to look through the lower window, or to crane up to see through the upper window. The upper windows, however, are good for visibility in steeper turns and cross-cockpit view in a right turn.
At maximum landing weights, approach and touchdown speeds are normally 112/102kt, but a "tactical" flare from 98kt reduces the landing roll from 1,900ft to 1,200ft. These speeds at 20,000kg were 96kt and 90kt, respectively.
The first flare, on landing in a gentle descent, needed a larger pull on the control column than I had anticipated, but the gear, which hangs free 500mm below its static loaded position, easily absorbs hard landings. At the maximum landing weight of 25,600kg, an impact speed of up to 550ft/min is allowed on to a paved runway (the gear will absorb a 390ft/min impact even at the maximum take-off weight). On a soft surface, with lesser maximum weights of 25,000kg and 25,800kg, the limits are 710ft/min and 550ft/min, respectively. On the second approach, I found ample elevator authority with a firm pull on the control column, to flare easily from a 1,200ft/min descent.
A maximum stop landing from a steep turning approach gave a ground roll of under 300m from touchdown. The lift-dump switch is by the flap lever; reverse is easy to select and the brakes powerful - Freddiani joined me to stand even harder on the brakes. Reverse thrust is selected only on the left-hand power levers.
AIR DROPPING
Supply and parachute dropping, are vital parts of any tactical freighter's task: to assess the G222's suitability for them, we set up a simulated dropping run over the sea. At 130kt with no flaps, the aircraft's attitude was again nose-high, at 7°, but with mid-flap it was 2-3° at 110kt, the prescribed drop-speed for this lightweight.
The rear under-fuselage divides to form a loading ramp and an upward-opening door. When horizontal, the ramp forms a platform for airdrops or deployment of parachutists. Rear side doors are used for rapid jumping sequences: the airflow becomes divergent under the flattened extreme aft of the fuselage, which assists this. Simultaneous opening of the cargo door and the side doors for parachuting is not allowed.
Flying with the tail ramp open increases the floor area from 21m2 (226ft2) to 25.68m2 and the cabin volume to 58m3 (2,000ft3). Floor strength in flight is 2t/m2.
Capacities range from 53 men or 42 fully kitted soldiers in transport, to 42 or 32, respectively, for parachute drops. Airdrops of up to 5t or two 2.5t loads together can be made, or six of 1,066kg in succession.
The cargo door and ramp opened in 15s, opening was accompanied, by a slight pitch down and some airflow rumble, could now be felt during turns. The roll rate is unaltered by having the doors open, but lateral stability is a bit lighter. The minimum drop speed is 1.15 Vs (stall speed), up to 140kt according to conditions and weight. Maximum speed with mid-flap is 170kt, and 150kt at full flap, leaving ample margins.
I positioned at 500ft above a ship, as a simulated drop-point marker, looking down over my knee through the lower windows. In a rapid climb-away, full power was applied, as the ramp was retracted (20s) and speed increased to 130kt. There is a marked pitch-up in this situation, and the rapid pitch trim was useful.
Similar trimming was needed in a simulated go-around at 96kt; the nose pitches well up, both from the power and from the flap retraction from full to mid. With a deliberately rapid pitch-up, the attitude reached 20° at 88kt, but slight forward stick-pressure quickly brought it back.
RETURN TO NAPLES
The final landing back at Naples was also made steeply, on an 8°descent path at 1,100ft/min, the flare was rapid and the stick-shaker briefly operated.
On the parking area, 360° turns were made with full tiller - equating to 65° of nose-wheel angle. If entered rapidly, at idle thrust and with some inside brake, the turn stopped quickly. With a progressive entry, at low speed without any brake, but with power on the outside engine, however, the minimum turning radii could be comfortably demonstrated: 5m at the outer wheels and 17.5m at the wingtip.
The ramp was deployed after shutdown to demonstrate loading attitudes. A switch on the load-master's panel, near the left paratroop door, was selected to "nose" and then "nose and main". An extra chamber in the nose-wheel shock absorber extended, to quickly set up a 4° tail-down attitude, reducing rear ground clearance from about 800mm to 500mm.
The ramp is 1.95m long and, using the 1.8m ramp extensions carried on board, the angle up to the main floor becomes easy for a vehicle to be driven on or a pallet pulled in with the installed winch. While the ramp can be set at 0° in the air only, it can be set at any of four angles up to 15° on the ground.
Similar chambers in the main gear shock absorbers next lifted the whole aircraft through 500mm in a level attitude, giving a platform height of over 1m to allow direct loading from a flat truck. These gear configurations are annunciated both on the load masters' and cockpit- overhead panels.
Main tyre pressures can also be temporarily varied between 3.5bar and 6.5bar (50-90lb/in2), between minimum and maximum weights, for operation from soft unprepared strips.
Intra-theatre airlift to minimal operating locations is facilitated by the fact that its multi-role capability is modular. The G222 designers aimed to bridge the load and range gap between the Boeing CH-47 and the C-130, with an edge over large helicopters in direct delivery to distant operations.
The engine is in production, and has higher thermodynamic potential. The airframe, designed for 20,000 flight hours, has been tested to 50,000 simulated flight hours: extension to 25,000h is available, after damage and corrosion assessment, based on long-service items in the Italian air force, which flies in salty conditions.
Renewed interest in this previously modestly selling military transport lies in US Air Force use of the Alenia's C-27 Spartan, a Thai air force contract, and in proposals for an upcoming US Army requirement. Presentations were made in December 1994 in Kuwait, and a bid for an Australian de Havilland Caribou replacement being prepared.
The G222, of which just 112 have been sold to date, has until recently been a (batch-selling) aircraft in irregular production. Alenia now sees a market for one aircraft a month over the next 20 years - its tooling capacity is two a month. Four are usually built "on spec", for rapid response to orders.
Source: Flight International
