PZL I-22 Iryda. Part 4. 1985.Last change: March 2020
271b Section 1985-03-05
PZL Iryda I-22
Combat training aircraft.
Construction. Part 4.
Construction PZL I-22 M-91, M-93 Iryda.
PZL I-22 Iryda is a twin-engine ridge. Construction of dural sheets and profiles using alloy steels and composites. Adapted to flights in difficult weather conditions and at night. The aircraft was designed based on the requirements of the Polish Ministry of National Defense in 1992, it also complied with British AP970 regulations. Regarding flight and operational characteristics, the aircraft met MIL-F-875 B / ASG.
A wing with a trapezoidal contour. The leading edge has a bevel of 14.46 degrees. The trailing edge is perpendicular to the plane's symmetry axis. The wing structure is half-shell, riveted, double-girder, non-split, geometric and aerodynamically twisted. Strength ribs milled with duralumin. Variable profile along the spans NACA64A010 and NACA64A210. Negative wing height: -3 degrees, wedge angle 0 degrees, geometric twist 1.73 degrees. Single girder, slotted, metal construction dampers, swing-out, three-support. Ailerons of metal structure, mass balanced, differently deflected. Position lights located on the wing tips. The landing lights are retracted from the bottom of each wing. In the caisson, the wings between the girders are integral fuel tanks, the panel structure reinforced in the places where four arms are suspended. The external fastening nodes are so-called wet, i.e. adapted for hanging additional tanks.
Oval fuselage, flattened at the bottom. Half-shell construction with duralumin frames and stringers. Technologically divided into four parts; nasal, anterior, medial and posterior. The nasal housing houses the front undercarriage chamber and electronics compartment. The front also called the cabin includes airtight crew cabins, under the cabin floor knots for fixing the cannon, ammunition tank, elements of the control system and gaps of radio-electronic equipment. The middle part is a strength one with reinforced frames. Here, the sash is attached with four fittings. Here are the grips and air ducts, engines, main landing gear and deck systems. In the area of the engines, the cover is made of titanium sheet, which is a fireproof barrier. The rear part of the half-shell conical hull houses the cylinders of the pneumatic and fire-extinguishing system, on the ridge before the tail there are plate aerodynamic brakes. At the end of the rear part of the hull there is a container for a braking parachute.
Crew pressure cabin, ventilated and air-conditioned. Powered by venting engine compressors. Air from the air conditioning and ventilation system also powers the pilot's overload suits used during aerobatics. Pressure and ventilation conditions are also maintained with one engine running. Rear cab height above 404 mm. Two individual plexiglass cabin covers, opening upwards backwards. A transition arc between the opening cabin covers. Reinforced windbreak consisting of a flat multilayer glass windscreen and two side windows. Windshield electrically heated, other windows heated with hot air. Armchairs thrown out, with an emergency rescue kit, cabin covers are crushed by a detonation cord. Initially, the Czech rocket seats VS-1 / BRI / P were used, in aircraft from No. 301 English Martin-Baker 10 PL. The seats can be fired when the cabins are closed - glass breakers built into the seat headrests. Back type crew parachutes. The oxygen system consists of a five-liter cylinder and two two-liter cylinders.
Vertical, half-crust, trapezoidal vertical bevel, +25 degrees, and NACA 64A009 profile. Double-girder vertical ballast. Metal rudder with sandwich construction, three-support, single-girder. Horizontal, semi-crust, trapezoidal, slanting + 29.8 degrees, negative elevation -6 degrees and NACA 64A009 profile. Horizontal ballast with variable wedge angle, hydraulically adjustable from 0 to -8.5 degrees. Two-piece rudders, of metal sandwich construction, three-legged. Direction and height rudders mass-balanced. Position lamp at the top of the vertical tail.
Rigid, pusher control system with hydraulic amplifiers in the aileron control system. Double tiller (bars and pedals). Flaps, horizontal stabilizer and hydraulically swinging aerodynamic brakes. Emergency release of pneumatic flaps. Electric aileron and rudder trim from both cabins. Motor control by means of a pusher system. The control system adapted to the autopilot body.
Three-unit chassis, with front wheel, hydraulically retractable into the hull recesses, double-acting oil-air shock absorbers, hydraulic disc brakes of the main wheels. Individual main wheels with dimensions of 630 x 210 mm, single front wheel 430 x 170 mm, controlled in the range of angles - / + 45 degrees .. Main chassis wheels suspended on suspension arms, front wheel on the swinging fork. Low-pressure tubeless tires enabled the use of the aircraft from grassy and ground airfields and leveled the vertical descent of the aircraft at a speed of up to 3.66 m / s. Front and main landing gear retractable in the flight direction. The undercarriage recesses are covered by hydraulically operated covers, which, when the undercarriage is extended, close again to protect against dirt. Emergency pneumatic landing gear extension. On the shins, landing gear extension lights.
Avionics of the M-91 aircraft.
M-91 aircraft equipment; It allows you to perform tasks in difficult weather conditions during the day and at night. The external and internal communication system is based on a multi-channel radio station controlled from both cabins, operating in the VHF 110 ... 149.975 MHz range and in the UHF 220 ... 399.975 MHz range. An onboard telephone was built into the radio. This telephone enables communication between the pilots, but also on the stand with the take-off mechanic, who plugs his own telephone into one of the two sockets located on the left side of the fuselage.
Because it is a training aircraft, the combination of on-board instruments is adapted to train the student in solving problems in emergency situations. The instructor, by moving the switches, can simulate damage to various instruments in the student's cabin. It can also disconnect the power of the aileron amplifiers. Any instructor intervention is automatically recorded by the on-board recorder.
Other device M-91: Automatic radio compass. Low altitude radio altimeter. Radio receiver informing about the passage over the beacon. Aircraft Identification System. An active response system for cooperation with ground-based radar detection, guidance and landing systems. Warning system, warning light and sound when a plane locates by a radar station.
Avionic equipment of the M-93 version.
Equipment of the M-93 version: identical in both cabins set of on-board analog instruments, VHF / UHF radio station RS6113, wired internal communication system with ground support, ARK-15M radio compass, RL-750W radio altimeter, ORS-2M beacon marker receiver, system transponder - foreign "SRO-2, warning system for radiation irradiation with the SPO-10 beam, system enabling emergency situations to be created by an instructor in the front cabin, S-13-100 photocarbine, or a camera to control the results of using SSz-45-1-100- armaments 05, ASP-PFD-I22 gyroscopic shooting sight with electronic control block, analogue weapon control system (UWS).
Avionic equipment of the M-93 S version.
On 26.05.1994, the rebuilt aircraft No. 1 ANP 01-05 was flown, registration SP-PWD with an even more developed avionics of the French company Sagem. It was also the beginning of flight tests of the most modern sight and navigation system, automatic, which was ever installed on a military aircraft in Poland. The PZL I-22 Iryda aircraft with the Sagem system and K-15 engines was the best version of the combat-training aircraft that could be used in the Polish Army.
New avionics included; Hrant Ferranti HUD indicator, two universal EFIS television screens from Bendix / King and the Uliss navigation system, consisting of; navigation computer, gyro platform and aerodynamic data center. The gyroscopic platform is spring-loaded. The laser turned out to be too expensive and more complicated (at that time).
The navigation system, although not visible at first glance, has become the most important new element by abruptly increasing the capabilities of the aircraft. Now the navigation is so accurate that for one hour of flight the deviation of the course is only 200 meters. It is the first navigation system in Poland independent of terrestrial transmitters, which cannot be compared with the post-Soviet RSBN navigation system. Such high accuracy of the tested system is possible thanks to cooperation with the GPS system, which corrects the drift of the gyroscopic platform. The GPS card has been built into the navigation computer. In 1994, Poland did not have access to all GPS system codes, which would be changed during the war. But even in the absence of a GPS system, the platform itself provides an accuracy of 1,800 meters per hour of flight. Not only that, the system allows you to correct the position of the aircraft relative to landmarks with known coordinates. You can enter up to 60 points, e.g. alternate airports, planned destinations, etc. Points can be entered before or during a flight.
An important element of the new avionics is CDU - Computer Display Unit. It acts as a computer terminal. The system consists of a screen and a set of switches. In the demonstration plane, the CDU was placed only in the first cabin, on the left side of the board. On the screen, you can configure image compositions, a set of information, for example, the order of actions in an emergency. There are about 50 of them on the Su-22 aircraft. Until now, the pilot had to know them by heart, and in flight, the pilot in stress can forget. Coordinates are entered via the CDU. The CDU automatically provides all information about the three nearest airports.
CDU works with HUD. The pilot can recognize the target visible in the HUD with a special marker and after pressing a button obtain information about its geographical coordinates and its elevation. It was possible to store up to 15 such information and even transfer it to, for example, another attack group.
The rear cabin has RHUD, i.e. the rear HUD presented on the screen. This is of paramount importance in the training process. The instructor occupying the rear seat constantly monitors and corrects possible errors of the trained pilot. So far, the instructor only monitors the general flight conditions and ensures safety. Having RHUD, he can see the effects of piloting and aiming.
The HUD is equipped with a small camera and all images shown by the head-up indicator are filmed on a standard VHS cassette. After the flight, you can watch positive and negative behaviors together by watching a movie.
EFIS are two identical screen devices that are interchangeable. In case of failure of one of them, the other can take over his tasks. One screen acts as an electronic compass, the other is a repetition of the HUD view. The compass acts as a radio compass. Only a full-scale slice can be displayed. It can present wind direction and strength, distance from waypoints and more. It should be emphasized that all measuring units are in Anglo-Saxon units, because such a standard prevails in NATO, but there would be no problem in scaling to metric units in the SI system. (At that time, Poland was not yet a NATO member).
The system is protected against failures in the form of a self-monitoring system. Information on the failure is given on the HUD, and information on the consequences of this failure can be obtained on the CDU. The pilot has full insight into the status of individual components of the aircraft, knows the consequences of failure and can make optimal decisions. In the event of a significant drop in power supply, e.g. generator failure, the system will display only the most important information enabling return to the airport.
The logic of the cabin is so well thought out that a few basic mechanical-analog instruments were retained as the last resort. It should be added that the introduction of the Sagem system would require changes to some aviation regulations in Poland.
A standard SARPP recorder, an electronic engine recorder for the operation of the Warsaw ATM engine and a complete novelty in Poland, the MBM device, i.e. the bubble memory module, were mounted on board. It is similar to those used in NATO combat units. Using a cassette, it is entered into the on-board system, and then read the course of the mission. This is nothing more than an operational recorder.
The entire modernized program of Irida included 35 flights. The flights were performed by experimental pilots Grzegorz Warkocki (former pilot Su-20) and Tadeusz Lechowicz (former pilot MiG-21 MF). The first three flights were to check whether the new devices did not change the characteristics of volatile machines. The first flight with the Sagem avionics launched was made on June 1, 1994, and was aimed at static calibration of instruments and checking the angle of attack indicator. The first navigational flight was made on June 15, 1994, and it was the tenth test flight. From the eleventh flight, tests began on the training ground using various types of weapons; on-board cannon, bombs, unguided missiles. Tests were also made in navigation using GPS systems and the inertial platform. These systems allowed to lead I-22 Iryda as if on a string, with an accuracy of single meters. At that time, no military aircraft operated in Polish aviation could.
It should be noted that with the use of the new avionics, the use of I-22 guided air-to-air missiles has become real, e.g. R-60 MK. In the future, it would be possible to build the recognition and response system produced by the Polish company Radwar under the license of Thomson, a laser rangefinder and infrared image observation and recording devices.
If the system was introduced into serial production, some further changes had to be made to make the pilot's working environment more readable. A CDU would also be installed in the second cabin. The joystick and engine controls should be changed according to the HOTAS system (hands on the controls), transferring some of the switches to them.
Measurable effects from the new avionics are undoubtedly the possibility of performing attacks previously impossible or ineffective. Exit to a point target at a specific time. Exit to a given point in "any" (difficult) weather conditions. Despite the use of unguided weapons, the aircraft proved to be more effective than combat Sukhoi Su-22 M 4. The conclusions of the research are clearly defined: I-22 M-93 S has become a training and combat machine, enabling the implementation of advanced training tasks and limited mission performance combat - fire support and reconnaissance. During this period, the Ministry of National Defense declared the purchase of three machines in the training and training version in 1994, another four in the following year. In total, it was intended to reach 40 aircraft.
On December 31, 1994, the M-93 aircraft obtained a certificate of capability to operate in Polish military units. Unfortunately, this did not mean much.
The power package depends on the aircraft version.
The I-22 M-91 aircraft has two single-flow PZL / K-5 turbojet engines (Kaszub-3 W 22), which is a development variant of the SO-3 W engine, from the TS-11 Iskra aircraft. 357 kg dry engine. Starting string 2 x 1 100 kG (2 x 1 080 daN). Engines placed on the airframe at an angle of 4 degrees down. Non-adjustable engine nozzles. Starting the electric motor using a starter motor, which also acts as a DC generator. Automatic start from an airport source with a voltage of 28 V or on-board batteries. The engines have recorders of operating parameters and fault indicators. Fire alarm of engines, automatic fire extinguishers in engine nacelles, double use during flight. Manually operated fire extinguishers (after closing the fuel supply to the engine). Air intakes with oval ducts turning into circular ones, moved away from the fuselage to separate the boundary layer.
The I-22 M-93 K aircraft has two single-flow PZL K-15 engines (Kaszub-15) with 2 x 1,500 kG (2 x 1,472 - 1,480 daN) take-off engines at 15,800 rpm. The dry weight of the engine is 340 kg. Main engine assembly 600 - 1,200 hours. The K-15 engine is the next generation of the K-5 engine. The K-15 engine is a single-shaft, single-flow engine equipped with a six-stage axial compressor with a supersonic first stage, has an annular combustion chamber and a single-stage turbine. The compressor drum impeller has a weld structure made of maraging steel. The blades are made of titanium and stainless steel. Electronically controlled aggregates. Installation of the K-15 engine and its installation on an airframe is analogous to the PZL / K-5 engine.
I-22 M-93 V aircraft. In 1994. One prototype aircraft was built (1 ANP 01-06, registration SP-PWE) and was equipped with British engines. The aircraft changed its number to No. 1 ANBP 01-01, and left the registration SP-PWE.
The I-22 M-93 V has two Rolls Royce Viper 535 engines, with 2 x 1,500 kG (2 x 1 492 daN) takeoff and 358 kg each. Installation of the Viper engine and its installation on an airframe is similar to the PZL / K-5 engine.
M-93 M version.
The M-93 M version is nothing more than an attempt to bring to a common standard all manufactured PZL I-22 aircraft and introduce them to the armament of the Polish Military Aviation, with an indication of the Navy. It was an attempt to save national wealth at the time the Program was already closed.
The plane was to have elevated vertical tail and turbolizers on the upper surface of the flap, but without inflows (bands) in front of the wings and new wing flaps. Armaments load was to increase to 2,075 kg.
Written by Karol Placha Hetman