English name: Dromedary
TYPE: Agricultural sprayer.
PROGRAMME: Designed to meet requirements of FAR Pt 23; prototype (SP-PBW) first flew 27 August 1976; further two prototypes; M18 awarded Polish type certificate 27 September 1978; eight preproduction aircraft used for operational trials; initial US certification on 23 January 1981; M18A followed on 8 September 1987 and M18B on 19 December 1995. Later certified in Argentina, Australia, Brazil, Canada, China, former Czechoslovakia, France, former East Germany, Italy, Lithuania, New Zealand, Spain, USA and former Yugoslavia.
Initial M18 single-seat version produced from 1979 to 1984; followed by M18A two-seater produced 1984 to 1996 and M18AS training version. These superseded from mid-1996 by improved M18B and BS, which remain current standard variants.
CURRENT VERSIONS: M18B: Standard production version from mid-1996. Improved performance development of M18A, awarded extension of Polish type certificate 27 January 1194; FAA certification granted 19 December 1995. Elevators have smaller, centrally located trim tabs; spring interconnect between elevators and flaps, and between ailerons and rudder; flaps-down deflection increased from 15 to 30°; maximum payload and overload MTOW increased. Normal category landing run reduced; flaps-down stalling speed reduced; lower control stick force values; enhanced static and dynamic longitudinal stability. Power plant and hopper as for M18A. More recent detail improvements have included 20 cm (8 in) lengthening of tailwheel leg; 20 per cent more efficient oil cooler; hydraulic (instead of multipiston) gear pump; third hinge added to rudder; anti-collision lights at wingtips instead of on fuselage; aerodynamic airscoop for ventilation system; main-gear leg fairings; hopper filling system for liquid chemicals on both sides of fuselage; and foaming agent loading system with special onboard pump.
Detailed description applies to M18B except where indicated.
M18BS: Two-seat dual-control trainer, generally as M18AS, but using M18B airframe. Prototype (SP-ZUW, converted from an earlier M18) first flew in November 1997. Polish type certificate awarded early 1998. Front (instructor's) seat reduces hopper capacity to 900 litres (238 US gallons; 198 Imp gallons) or 500 kg (1,102 lb). Two produced for Iranian operator and three for Hellenic Air Force. Greece has ordered three more.
M18C: Improved M18B, with 895 kW (1,200 hp) PZL Kalisz K-9 engine. Prototype flown in August 1995, but abandoned in favour of improvements to existing B and BS.
Turbune Dromader: Turboprop versions with 761 to 875 kW (1,020 to 1,173 shp) P&WC PT6A-45A/B/R or PT6A-65R/AG/AR engines with Hartzell propeller. Developed initially by James Mills Turbines Inc in USA and continued by Turbine Conversions Ltd. Variants with Honeywell 746 kW (1,000 shp) TPE331-10 or T53-L-7 also available from respective STC holders.
CUSTOMERS: Total of 731 built (all versions) by end of 2002, of which approximately 90 per cent for export; 28th production batch under way in 2002; sold to operations in Argentina, Australia, Brazil, Bulgaria, Canada, Chile, China, Cuba, former Czechoslovakia and East Germany, Greece (30 for firefighting), Hungary, Iran, Italy, Morocco, Nicaragua, Poland, Portugal, Spain, Swaziland, Trinidad, Turkey, USA (more than 200), Venezuela and former Yugoslavia.
DESIGN FEATURES: Emphasis on crew safety (cockpit located behind large mass concentrations of power plant and hopper; reinforced cockpit structure and roof for higher crashworthiness in case of turnover; wire cutters forward of cockpit; windscreen bird-impact resistant; fuel tanks in outboard wings, away from cockpit; steel cable between cockpit and fin for vertical tail protection against collision with overhead power lines. No members of fuselage load-carrying truss extend through hopper. All major airframe component assemblies interchangeable, with no individual fitting required. Mainwheels not subject to lateral travel during shock-absorbers' deflection, thus reducing tyre wear-off. Expansion mandrels used in centre-section-to-outboard wing attachment joints for facilitated installation and removal. Whole aircraft, in disassembled condition, with operational and ground maintenance equipment, can be carried in a single 12.2 m (40 ft) container. All parts exposed to chemical contact treated with polyurethane or epoxy enamels, or manufactured of stainless steel; detachable fuselage side panels of airframe inspection and cleaning; braced tailplane.
Wing sections NACA 4416 at root, NACA 4412 at end of centre-section and on outer panels; incidence 6°.
FLYING CONTROLS: Conventional and manual. Mass and aerodynamically balanced slotted ailerons with trim tabs, actuated by pushrods; aerodynamically and mass-balanced rudder and horn-balanced elevators with trim tabs, actuated by cables and pushrods respectively; hydraulically actuated two-section trailing-edge slotted flaps. Control surface movements: ailerons +21/+17°; elevators +27/-17°; rudder ±23°; flaps max 30°. See also Current Versions M18B paragraph above.
STRUCTURE: All-metal; steel-capped duralumin wing spar; fuselage mainframe of helium-arc welded chromoly steel tube, oiled internally against corrosion; duralumin fuselage side panels and stainless steel bottom covering; corrugated inboard flap and tail unit skins.
LANDING GEAR: Non-retractable tailwheel type. Oleo-pneumatic shock-absorber in each unit. Main units have 800x260 tyres and are fitted with hydraulic disc brakes, parking brake and wire cutters. Fully castoring tailwheel, lockable fore take-off and landing, with tyre size 380x150.
POWER PLANT: One PZL Kalisz ASz-621R nine-cylinder radial air-cooled supercharged engine (731 kW; 980 hp at 2,200 rpm), driving a PZL Warszawa AW-2-30 four-blade constant-speed aluminium propeller. Integral fuel tank in each outer wing panel, combined usable capacity 712 litres (188 US gallons; 157 Imp gallons). Gravity feed header tank in fuselage. For ferrying, additional fuel capacity in chemical hopper. Oil capacity 70 litres (18.5 US gallons; 15.4 Imp gallons).
ACCOMMODATION: Single adjustable seat in fully enclosed, sealed and ventilated cockpit stressed to withstand a high g impact. Additional cabin located behind cockpit and separated from it by a wall. Latter equipped with rigid, rear-facing seat with protective padding and safety belt, port-side jettisonable door, windows (port and starboard), fire extinguisher and ventilation valve. Communication with pilot provided via window in dividing wall, and by intercom. In M18BS, standard hopper is replaced by smaller one, permitting installation of bolt-on instructor's cabin. Standard hopper of M18B and instructor's cockpit of M18BS interchangeable. Glass fibre cockpit roof and rear fairing, latter with additional small window each side. Front cockpit of M18BS has more extensive glazing. Adjustable shoulder-type safety harness. Adjustable rudder pedals. Quick-opening door on each side of front cockpit; port door jettisonable.
SYSTEMS: Hydraulic system, pressure 98 to 137 bar (1,421 to 1,987 lb/sq in), for flap actuation, disc brakes and dispersal system. Electrical system powered by 28.5 V 100 A generator, with 24 V 28 Ah lead-acid battery and overvoltage protection relay.
AVIONICS: Comms: Bendix/King KX 155 or KY 196A com transceiver.
Instrumentation: KI 208 course indicator, VOR-OBS indicator, artificial horizon with turn and bank indicator, gyrocompass, radio compass, transponder and stall warning.
EQUIPMENT: Glass fibre epoxy hopper, with stainless steel tube bracing, forward of cockpit; capacity 2,500 litres (660 US gallons; 550 Imp gallons) of liquid or 2,200 kg (4,850 lb) of dry chemical. Smaller hopper in M18BS. Deflector cable from cabin roof to fin.
M18 can be fitted optionally with several different types of agricultural and firefighting systems, as follows: spray system with 54/96 nozzles on spraybooms; dusting system with standard, large or extra large spreader, atomising system with 10 atomisers; water bombing installation; firebombing installation with foaming agents; and multifunction firefighting system (water bombing or sequential line-drops). Aerial application roles can include seeding, fertilising, weed or pest control, defoliation, forest and bush firefighting, and patrol flights.
Special wingtip light permit agricultural flights at night, and aircraft can operate in both temperate and tropical climates. Navigation lights, cockpit light, instrument panel lights and two rotating beacons standard; wingtip positioning/strobe lights optional. Landing lights and taxying light; night working lights optional. Built-in jacking and tiedown points in wings and rear fuselage; towing lugs on main landing gear. Cockpit fire extinguisher and first aid kit.