Antonov An-28


COMMENT: Found at Jane's All the World Aircraft Demo... NATO reporting name: Cash

The O.K.Antonov bureau developed the An-28 for service on Aeroflot's shortest routes, particularly those operated by An-2s into places relatively inaccessible to other fixed-wing types. It is suitable for carrying passengers, cargo and mail, for scientific expeditions, geological survey, forest fire patrol, air ambulance or rescue operations, and parachute training. The An-28 will not stall, even with the control column held in the extreme rearward position, because of the action of its automatic slots. If an engine fails, the upper surface spoiler forward of the aileron on the opposite wing is opened automatically; as a result, the wing bearing the dead engine drops only 12~ in 5 s instead of the 30~ that it would drop through loss of lift without the action of the Antonov patented spoiler. The fixed tailplane slat, also patented, improves handling during a high incidence angle climb. Under icing conditions, if the normal anti-icing system fails, ice collects on the slat rather than the tailplane, to retain control.

The early history of this twin-turboprop light general purpose transport has been given in many previous editions of Jane's. Official Soviet flight testing was completed in 1972, and the production designation An-28 was allocated during 1973. The first pre-production An-28 (SSSR-19723) originally retained the same engines as the prototype, but in April 1975 (re-registered SSSR-19753) it flew for the first time with 716 kW (960 shp) Glushenkov TVD-10 turboprops (now WSK-PZL Rzeszow TWD-10B). An-28 production was entrusted to PZL Mielec in 1978, and a temporary type certificate, under Soviet NLGS-2 regulations, was awarded on 4 October that year to the second Soviet built pre-production aircraft (originally SSSR-19754, later SSSR-48105).

Polish manufacture began with an initial batch of 15 aircraft, and 163 had been ordered by 1 January 1991. First flight by a Polish built An-28 (SSSR-28800) was made on 22 July 1984, and this version received its full Soviet type certificate on 7 February 1986. Flight trials with PT6A-65B turboprops were due to begin in second half of 1991.

TYPE : Twin-turboprop short-range transport.

WINGS: Braced high-wing monoplane, with single streamline section bracing strut each side. Wing section TsAGI P-II-14 (thickness/chord ratio 14 per cent). Constant chord, non-swept no-dihedral centre-section, set at 4~ incidence; tapered outer panels have 2~ dihedral, negative incidence and 2~ sweepback at quarter-chord. Conventional two-spar all-duralumin torsion box structure, with steel attachment fittings. Duralumin automatic leading-edge slats over full span of outer panels. Entire trailing-edges hinged, the single-slotted mass and aerodynamically balanced ailerons being designed to droop with the large, two-segment double-slotted flaps. Unpowered ailerons and hydraulically actuated flaps are of duralumin, with fabric and CFRP skins respectively; port aileron has a CFRP trim tab. Slab type spoiler, also of CFRP, forward of each aileron and each outer flap segment at 75 per cent chord. Thermal anti-icing of wing leading-edges by engine bleed air. Short stub-wing extends from each side of the lower fuselage, carrying the main landing gear unit and providing lower attachment for the wing bracing strut.

FUSELAGE : Conventional all-metal semi-monocoque non-pressurized structure. Underside of rear fuselage upswept and incorporating clamshell doors for passenger and cargo loading.

TAIL UNIT : Cantilever all-metal structure. Twin fins and rudders, mounted vertically on an inverted-airfoil, no-dihedral fixed incidence tailplane. Conventional elevators. Fixed leading-edge slat under full span of tailplane leading-edge. Electrically actuated trim tab in each rudder and each elevator; main controls are unpowered. Thermal (engine bleed air) anti-icing of tailplane and fin leading-edges.

LANDING GEAR : Non-retractable tricycle type, with single Soviet built wheel and PZL oleo-pneumatic shock absorber on each unit. Main units have wide tread balloon tires of Soviet manufacture, size 720x320mm, pressure 3.5 bars (51 lb/sq in), and are mounted on small stub-wings which curve forward and downward at front to serve as mudguards. Steerable (+-50~) and self-centering nosewheel, with size 595x185x280mm Stomil (Poland) type, pressure 3.5 bars (51 lb/sq in). Soviet multi-disc hydraulic brakes on main units, and Soviet inertial anti-skid units. Ski gear under development.

POWER PLANT : Two 716 kW (960 shp) WSK-PZL Rzeszow TWD-10B turboprops, each driving an AW-24AN three-blade automatic propeller with full feathering and reversible-pitch capability. Two centre-section and two outer-wing integral fuel tanks in wing spar boxes, with total capacity of 1960 litres (518 US gallons; 431 Imp gallons). Refueling point on each tank. Oil capacity 16 litres (4.2 US gallons; 3.5 Imp gallons) per engine. Air intakes lined with epoxy laminate and anti-iced by engine bleed air; propellers, spinners and pilot heads anti-iced electrically. ACCOMMODATION : Pilot and co-pilot on flight deck, which has bulged side windows and electric anti-icing for windscreen, and is separated from main cabin by a bulkhead with connecting door. Dual controls standard. Jettisonable emergency door at front on each side. Standard cabin layout of passenger version has seats for 17 people, with six single seats on port side, one single seat and five double seats on starboard side of aisle, at 72 cm (28 in) pitch. Aisle width 34.5 cm (13.5 in). Five passenger windows in each side of cabin. Seats fold back against walls when aircraft is operated as a freighter or in mixed passenger/cargo role, the seat attachments providing cargo tiedown points. Hoist of 500kg (1102 lb) capacity able to deposit cargo in forward part of cabin. Entire cabin heated, ventilated and soundproofed. Outward/downward opening clamshell double door, under upswept rear fuselage, for passenger and cargo loading. Emergency exit at rear of cabin on each side.

SYSTEMS: No air-conditioning, pressurization or pneumatic systems. Hydraulic system for flap and spoiler actuation, main brakes and nosewheel steering, with emergency backup system for spoiler extension and main braking. Primary electrical system is three-phase AC, with two engine driven alternators providing 200/115V power for heating systems, engine vibration monitoring, fuel pump, radio, recorders, and instrument lights. Transformer-rectifiers on this system provide 36V AC power for pressure gauges, artificial horizon, navigation and recording equipment, and 27V DC for control systems and signalling, internal and external lighting, firefighting system, propeller pitch control and feathering, radio, and engine starting and monitoring systems. In emergency, 36V AC can be provided by a static inverter and 27V DC by two 25Ah batteries. Thermal (engine bleed air) anti-icing of outer-wing, fin and tailplane leading-edges. Electric anti-icing of flight deck windscreen, propellers, spinners and pilot heads. Oxygen system (for crew plus two passengers) optional. No APU.

AVIONICS : Standard avionics include Baklan-5 (USSR) VHF com radio, R-855UM (USSR) VHF emergency locator transmitter, ARK-15 radio compass, MRP-66 marker beacon receiver, RW-5 or A-037 radio altimeter, Grebien-1 navigation unit, BUR-1-2A flight recorder, and SGU-6 intercom. Blind-flying instrumentation standard.

DIMENSIONS, EXTERNAL:
Wing span..............................22.063m (72ft 4{1/2} in)
Wing chord: at root.......................2.20m (7ft 2{1/2} in)
mean aerodynamic.......................1.886m (6ft 2{1/4} in)
at tip..................................1.10m (3ft 7{1/4} in)
Wing aspect ratio...........................................12.25
Length overall.........................13.10m (42ft 11{3/4} in)
Fuselage: Length........................12.68m (41ft 7{1/4} in)
Max width...............................1.90m (6ft 2{3/4} in)
Max depth...............................2.14m (7ft 0{1/4} in)
Height overall................................4.90m (16ft 1 in)
Tailplane span..........................5.14m (16ft 10{1/4} in)
Wheel track..................................3.405m (11ft 2 in)
Wheelbase...............................4.354m (14ft 3{1/2} in)
Propeller diameter........................2.80m (9ft 2{1/4} in)
Propeller ground clearance................1.25m (4ft 1{1/4} in)
Distance between propeller centers.......5.20m (17ft 0{3/4} in)
Rear clamshell doors: Length.............2.40m (7ft 10{1/2} in)
Total width: at top.....................1.00m (3ft 3{1/4} in)
at sill....................................1.40m (4ft 7 in)
Emergency exits (rear, each): Height...........0.91m (3ft 0 in)
Width........................................0.51m (1ft 8 in)
DIMENSIONS, INTERNAL:
Cabin, excl flight deck: Length...............5.26m (17ft 3 in)
Max width...............................1.74m (5ft 8{1/2} in)
Max height...................................1.60m (5ft 3 in)
Floor area........................approx 7.5 m2 (80.73 sq ft)
Volume...........................approx 14.0 m{3} (494.4 cu ft)
AREAS:
Wings, gross.............................39.72 m2 (427.5 sq ft)
Ailerons (total)..........................4.33 m2 (46.61 sq ft)
Trailing-edge flaps (total)..............7.986 m2 (85.96 sq ft)
Spoilers (total).........................1.667 m2 (17.94 sq ft)
Fins (total)............................10.00 m2 (107.64 sq ft)
Rudders (total, incl tabs)................4.00 m2 (43.06 sq ft)
Tailplane.................................8.85 m2 (95.26 sq ft)
Elevators (total, incl tabs)..............2.56 m2 (27.56 sq ft)
WEIGHTS AND LOADINGS:
Weight empty, equipped..........................3900kg (8598 lb)
Max fuel load...................................1529kg (3371 lb)
Max payload.....................................2000kg (4409 lb)
Max T-O and landing weight.....................6500kg (14330 lb)
Max zero-fuel weight...........................5884kg (12972 lb)
Normal wing loading.................153.5kg/m2 (31.5 lb/sq ft)
Max power loading........................4.64kg/kW (7.62 lb/shp)
PERFORMANCE (at max T-O weight):
Never-exceed speed (VNE)....210 knots (390km/h; 242mph)
Max level and max cruising speed at 3000m (9850 ft).....
.....189 knots (350km/h; 217mph)
Econ cruising speed at 3000m (9850 ft).....
.....181 knots (335km/h; 208mph)
Lift-off speed........................73 knots (135km/h; 84mph)
Approach speed........................70 knots (130km/h; 81mph)
Landing speed, flaps down.............76 knots (140km/h; 87mph)
Max rate of climb at S/L......................500m (1640 ft)/min
Rate of climb at S/L, one engine out...........210m (689 ft)/min
Service ceiling...........................above 6000m (19685 ft)
Min ground turning radius....................16.00m (52ft 6 in)
T-O run............................................260m (853 ft)
T-O to 10.7m (35 ft).............................360m (1180 ft)
Landing from 15m (50 ft).........................315m (1035 ft)
Landing Roll........................................170m (558 ft)
Range:
max payload, no reserves.............302 nm (560km; 348 miles)
max fuel and 1000kg (2205 lb) payload, 30 min
reserves............................736 nm (1365km; 848 miles)
g limit........................................................+3


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Created January 25, 1996 Back to
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