PZL I-22 Iryda. Part 1. 1985.Last change: March 2020
271b Section 1985-03-05
PZL Iryda I-22
Combat training aircraft.
Construction. Part 1
Construction of the Iskra-22 aircraft, according to the completed initial design. 1979.
The aircraft was intended for training, training and performing fire support, fighting ground and air targets. Operating day and night in harsh weather conditions. Double crew. The aircraft is a twin-engine ridge in a classic layout. Made of aluminum alloys, steel and composites.
The wing is unsealed, attached at four points to the fuselage. Span 9.60 m, area 19.92 sq m, 25% chord 14.5 degrees, elongation 4.63, wedge angle 1.5 degrees, raise 2 degrees. Profile at the base of the wing NACA 64210, which towards the ends of the wing was modified by gradually lowering the nose and increasing runoff. Profile modification was developed and tested at the Faculty of Mechanical Engineering, Power Engineering and Aviation at Warsaw University of Technology. The wing caisson was used as an integral fuel tank with a capacity of 1 110 liters. Half-shell construction with a front girder in 16% of the chord and a rear girder in 56% of the chord. Ailerons and single-gap flaps occupy 30% of the wing chord. Aerodynamically compensated and mass balanced shuttlecocks. Swiveling 17 degrees down and 50 degrees up. Darts suspended at two points. Flaps to take off 20 degrees, and to landing 50 degrees. Flaps suspended in three points. Aileron and flap drainage of sandwich construction with polyurethane foam filler.
The fuselage of the half-shell structure is technologically divided into four parts; nasal, cabin, middle and rear. The nose section houses the front undercarriage recess and equipment available when the metal cover is folded up. The cabin section accommodates two pilots in a tandem arrangement with a second seat 0.39 m high. The pressure and air-conditioned cabin with individual covers tilted to the side or raised. The final solution was to be taken at the technical design stage. The wing, main chassis and fittings for Kaszub-3 W 22 or Kaszub-15 engines were attached to the central part of the fuselage. Note that the drive was already imposed then. In the central part there is also a main fuel tank with a capacity of 1 360 liters. The chassis and bonnet covers are hydraulically moved. Air intakes matched to both types of engines. The rear part of the fuselage also supported the engines, it had air brakes with an area of 2 x 0.3 m2. Through the flange connection she maintained a vertical tail. At the tip of the fuselage is a recess parachute.
Horizontal tail of the plane with a span of 4 m, area 4.6 m2, elongation 3.48, bevel at 25% of the chord 26.1 degrees. Mounted to the vertical stabilizer at a height of 0.895 m from its base. The system is similar to Lim-5 aircraft. The horizontal crease was adjusted in range; up +4 degrees, down -7 degrees. Tiltable elevator; up +24 degrees, down –12 degrees. Horizontal, half-shell structure with two girders at 12.5% and 50% of the chord. It was divided in the plane of symmetry for assembly. Rudder with aileron-like structure, also mounted at two points. Vertical and horizontal fixation with NACA 64-009 profile. Vertical flange with an area of 3,234 m2, height 1,96 m, slant at 25% of the chord 41.1 degrees. The rudder tilts 25 degrees left and right. Vertical fixation also with half-shell construction with two girders placed in 15% and 50% of the chord. Back wall closing in 68.5% of the chord. A rudder of a construction similar to ailerons.
Chassis with a base of 4.876 m and a track width of 2.71 m. The size of the wheels and tires was chosen for operation with soil lanes. The MiG-21 aircraft was used as the reference base, with the main wheels producing 8 daN / cm2 rut with a depth of 6.4 cm. For the Iskra-22 aircraft, it was assumed that for the maximum take-off mass in the basic version in a soil with a strength of 6 daN / cm2 the rut should not be deeper than 6.5 cm. After analysis, this gave main wheels with a size of 670 x 210 mm and a maximum pressure in pneumatics of 7 daN / cm2. Front wheel with dimensions of 430 x 170 mm and pressure in pneumatics 5 daN / cm2. Main wheels equipped with disc brakes. Main landing gear with a drop strength of 3.66 m / s at the maximum weight of the basic version without suspensions. Main chassis with control arms with a two-stage raised shock absorber and telescopic strut. Front chassis equipped with a two-stage shock absorber placed in the shin and a shimmy vibration damper.
The rigid, pusher and girder aircraft control system, with amplifiers in the aileron system and vibration dampers. Two-circuit hydraulic installation with an operating pressure of 210 atmospheres. Initially, only 140 atmospheres were planned, which turned out to be insufficient for a training-combat aircraft. The main circuit intended for retracting and extending the chassis, aerodynamic brakes, braking the wheels, moved wing flaps. The amplifier circuit was used to power the ailerons, emergency landing gear extension, wing flaps for landing and braking the main wheels.
The pneumatic system was to be used only for lifting the cabin covers, if the option of lifting upwards backwards was chosen. Working pressure 150 atmospheres.
The air conditioning was to ensure the temperature in the cabin in the range of 17-27 degrees C and overpressure of 0.3 daN / cm2.
The anti-icing system consisted of three elements. Electric windscreen heating with 115 V and 400 Hz. Spraying the windshield with alcohol. Heating air shafts with air taken from compressor bleeds.
Oxygen system with a capacity of 12 liters, placed in three cylinders, each 4 liters and an initial pressure of 150 daN / cm2.
The fuel installation was to ensure reaching a ceiling of 15,000 m and an inverted flight for a minimum of 30 seconds. The installation capacity is 2,000 kg, and in the basic version limited to 1,100 kg, because the aircraft was to have only a fuselage tank. In the strengthened (development) version 900 kg in the wing tank and on external suspensions 2 x 320 kg.
Fire protection system, the basic element of which was to be cylinders with freon located in the engine area.
The layout of the cabin, the arrangement of indicators, instruments, switches, generally like on a MiG-21 aircraft. This was logical, because most of the pilots had to switch to the Iskra-22 aircraft on the MiG-21 aircraft. The Czechoslovakian VS-1BRI ejected armchairs were to provide rescue from a height of 0 m and a minimum speed of 150 km / h.
Electrical installations were to supply electricity; 28 V DC, 115 V 400 Hz single phase AC, 3 x 36 V 400 Hz three phase AC. The primary source were to be two GSR-St-6000A generators with 6 kW power. However, it soon turned out to be too little, so 2 x 9 kW was postulated. The choice of the current-starter model was to be made at the technical design stage. Two batteries were the spare energy source.
In the field of pilot-navigation equipment and radio-electronic devices (systems), the completed initial design only specified the equipment of the basic version. For communication, the Soviet radio station R-832 M, which was to be replaced by the Polish radio station UNIMOR. For navigation, the ARK-15 M radio compass and the RW-5 radio altimeter. Both in the future replaced by devices developed in Poland. Receiver signals ORS-2 beacon and APRK-7K half-compass, both new devices of Polish design and production. The aircraft was to be equipped with a set of special systems, such as a combat aircraft; active SOD-57M response system, SRO-2 recognition (20) and SPO-10 radiation beam warning (Siren). The AFP-21 PFD sight from the MiG-21 aircraft.
The barrel armament is a 23mm GSz-23 cannon with a supply of 200 rounds. Under the wings there are 4 knots with a load capacity of 500 kg, but the total capacity for the basic version 1 100 kg, and for the development 2 000 kg. Suspended bombs up to 500 kg. S-5 non-guided missiles in 8, 16 or 32 tanks. R-3 S air-to-air infrared homing missiles.
The development version of the aircraft was to receive much richer avionics. Among other things, the navigation system working on meter waves SNM-72, which was to be developed.
Design data of Iskra-22
The data from Iskra-22 are as follows; length - 13.435 m, height - 3.85 m, span 9.60 m, parking angle 2 degrees, curb weight 3 650 kg, which is already 250 kg more than in the preliminary design assessed by the Ministry of National Defense. Take-off weight, without suspension, 5 100 kg in the basic version, take-off weight 6,000 kg in the development version, maximum weight in the basic version 6 200 kg, maximum weight in the development version 7 200 kg.
Basic performance, without suspension, for a mass of about 4,550 kg was for the basic and development versions respectively; maximum speed on H-0 m - 920, 990 km / h, allowed number Ma - 0.85, 0.85, minimum speed in horizontal flight - 210, 210 km / h, maximum climb at the ground - 42, 65 m / s, maximum climb with one engine running - 12, 22 m / s, practical ceiling - 13,500, 15,100 m, climb time at 11,000 m - 446, 250 seconds, technical (calculation) range of the aircraft with 1,100 kg of fuel per altitudes 0 m - 500, 463 km, and at 11,000 m - 1,210, 1,187 km, with increased amounts of fuel up to 2,000 kg at an altitude of 11,000 m - 2,550, 2,500 km. The maximum range for the development version was 3,100 km. With a weight of 5 100 kg without suspensions for the basic and development version, the take-off was to be - 700, 490 m, take-off length on H-15 m - 985, 785 m, landing length from H-15 m - 1 280, 1 330 m, speed touchdown - 203 km / h, run-up - 830, 860 m. With a take-off mass of 6,000 kg, the run-up of the basic version was supposed to be 950 m, a development run-up of 670 m. With a mass of 7 150 kg, run-up 1 080 m. basic and development with four 250 kg bombs was to amount to 120-300 km. Range for development with 2 x 500 kg and 2 x 250 kg bombs - 240 km.
Written by Karol Placha Hetman