PZL I-22 Iryda. Part 2. 1985.Last change: March 2020
271b Section 1985-03-05
PZL Iryda I-22
Combat training aircraft.
Construction. Part 2
Construction PZL I-22. 1987 year.
On January 25, 1987, the first comprehensive article on PZL I-22 was published in the weekly Skrzydlata Polska. Among the many information, it was stated that the plane was just undergoing flight tests which were directed by Eng. Włodzimierz Stępień. The following T-T data are also provided; size; span 9.60 m, length 13.22 m, height 4.30 m, airfoil surface 19.92 m2, chassis base 4.90 m, main chassis wheel track 2.71 m, weight; empty plane 3 962 kg, max 7 493 kg, overload +8 g, -4 g, performance; max speed at 0 m 980 km / h, max number Ma 0.85, ceiling 12 800 m.
Full metal wings, half-shell, double-girder, non-split. Laminar profile and aerodynamic torsion were used. Lotto weight balanced. Slotted flaps hydraulically swingable for takeoff by 20 degrees and for landing 40 degrees. In the event of a hydraulic failure, the flaps can be swung out pneumatically.
Metal fuselage of half-shell structure: frame and longitudinal. Seats arranged in tandem arrangement, rear with an elevation. The equipment compartment is located under the rear seat. Individual cab fairings are lifted by pneumatic jacks. The windshield windscreen is electrically heated and its activation is automatic. In addition, spirit was sprayed on the windscreen from the outside. So that the windows in the cabin do not evaporate constantly they are inflated with hot air. The cabin is equipped with a ventilation and air conditioning system. The system regulates the pressure value and the rate of change of this pressure depending on the flight altitude. The system regulates the temperature in the cabin. Air conditioning air is taken from the compressor bleeds of both engines. The air also powers the pilot's overload suits. Front and rear cabin equipment is identical, which allows piloting the aircraft from both cabins. The front cabin is adapted for exercise in flight without visibility by instrument. The rear cab instructor can simulate various avionics faults. The engine air holds are also heated by the hot air taken from the compressor bleeds, which protects against icing.
The composition of the aircraft compared to the initial design has changed radically. It was no longer a cross type, but a classic, horizontal one attached to the hull. Semi-shell metal structure. Mass balanced steers. Horizontal fixation divided into rudder and ballast with variable wedge angle, adjustable hydromechanical actuator. Hydraulic amplifiers were used in the control system.
Three-support chassis with single wheels. Double-acting oil-pneumatic shock absorbers. Main chassis disc brakes. Retracting and extending the landing gear using a hydraulic system. Emergency landing gear is extended by a pneumatic system. Additional parking brakes were used as an emergency. Low-pressure tubeless tires enable take-offs and landings on concrete, grass and dirt lanes.
PZL I-22 engine assembly of the first versions;
Two SO-3 W 22 single-flow turbojet engines with 2 x 1 080 daN thrust, which were later designated PLZ K-5.
PZL I-22 fuel installation of the first versions;
The capacity of internal fuel tanks is 2 410 liters. Additionally, two additional tanks with a capacity of 2 x 380 liters can be suspended. The fuel is supplied by two electric pumps. In case of failure of one of them, the other covers the demand for both engines. First, fuel is used from suspended tanks, and then from tanks in the wings. The fuel system enables reverse flight. The amount of fuel is measured by a capacitive fuel meter. His readings are presented in both cabins. The pilot receives information about the total amount of fuel, the amount of fuel in the hull tanks. Traffic lights indicate empty suspended tanks, wing tanks and a critical amount of fuel. The aircraft is refueled via a central inlet. You can also refuel each tank individually.
PZL I-22 fire protection installation of the first versions;
It is intended for signaling and extinguishing a fire in engine nacelles. The basis is two cylinders filled with freon. They make it possible to extinguish a fire twice during a flight. The pressure in the cylinders is controlled on the manometers visible after opening the hatches on the ground.
PZL I-22 hydraulic installation of the first version;
It is one of the basic force installations on the plane. It consists of two independent circuits; main installation and installation of aileron amplifiers. The main installation causes; extension and retraction of the chassis, wing flap settings and their maintenance in three positions, extending and retracting the aerodynamic brakes, changing the wedge angle of the horizontal tail, releasing and rejecting the braking parachute, braking the main landing gear wheels, and in the differential system the possibility of turning by plane during taxiing, emergency and parking braking of the main landing gear wheels. The installation operates at a pressure of 21 Mpa. Airport power generators are used on the ground.
PZL I-22 pneumatic installation of the first versions;
It consists of three independent installations fed from onboard cylinders filled with nitrogen at a nominal pressure of 15 Mpa. The pneumatic system performs the functions of emergency installations. Sets the flaps to landing position, extends the landing gear. The installation normally opens and closes the cabin covers and encapsulates the closing through hoses. All cylinders are charged with a common valve.
Armament PZL I-22 first versions;
The permanent armament consists of a two-barrel cannon. Suspended equipment is 4 knots under the wings, each with a load capacity of 500 kg, but the total capacity is 1,200 kg.
Written by Karol Placha Hetman