PZL I-22 Iryda. Part 2. 1985.

Kraków 2008-08-01

271b Section 1985-03-05

PZL I-22 Iryda


Combat training aircraft.

History PZL I-22 Iryda. Part 2.

PZL I-22 Iryda nb 105. 2017. Photo by Karol Placha Hetman
PZL I-22 Iryda nb 105. 2017. Photo by Karol Placha Hetman

Start of technical project implementation. 1980 year.

At the beginning of 1980, the deputy minister of engineering, General Modrzewski, approved the „B+R i W” work plan for the year started. According to the plan, the Iskra-22 technical project and testing of Kaszub-3 W 22 engines were to be completed in the third quarter of the year.

The country's economic situation became increasingly difficult. In addition, CCCP troops entered Afghanistan. And what of it that at subsequent meetings on the nodal problem on May 12, subsequent arrangements and deadlines for their implementation fell, as the funds allocated were ever smaller. Foreign exchange funds, which were granted at the central level, were particularly drastically reduced.

So task B started very slowly. The WSK PZL-Mielec website participated in it to a different extent and with constantly changing organizational systems that were to be the antidote to the crisis

Already in June 1978, the Institute of Aviation placed an order for technical designs of wing and horizontal tail at OBR SK Mielec. Not much resulted from this, because there was not yet a technical assessment of the Ministry of National Defense Committee. The work of reality has not begun. In mid-November 1978, responsible for stage C (prototyping), CN-PSL ordered OKB SK Mielec to make wings and horizontal gates for the prototypes (7 sets). Also during this period, work was not started. Top-down schedules and orders were unrealistic, but for companies participating in the program they were obligations. In Mielec, only organizational reasons for starting activities appeared. Here, prototypes of products received an explicit designation "300" (W-300), which symbol was used for the purpose of correspondence between interested parties.

At the end of November 1979, the Institute of Aviation canceled its orders (for which relevant contracts were already prepared for signature) and placed new ones in their place. The order concerned wings, tail and rear of the fuselage together with technical documentation, calculations and technical conditions. As usual, the dates were very short, not to say that yesterday. The unrealistic deadline of 1980-08-30 was implemented much later.

In January 1980, the Institute of Aviation developed a timetable for preparing construction documentation which is the basis for planning part of their work for all those implementing stage B. And the contract between the Institute of Aviation and OBR SK Mielec was only signed in March 1980, and it was logical because only then stage A was officially completed. In practice, stage B started at the beginning of 1980, and at the end of November the technical design of the front and cabin parts of the fuselage and front landing gear. In August 1980, technical documentation for wings and tail was ready.

The beginnings of prototype construction. 1980 year.

The existence of this documentation gave grounds to start preparations for the start of stage C, i.e. the construction of prototypes. This work actually began at the beginning of 1980.

But here too there were difficulties due to shifts in the scope of responsibility for individual tasks. As we remember, CNPSL in Warsaw was to be responsible for stage C. However, good changes took place and OBR SK Mielec became the main contractor again. Previously issued orders from subcontractors were replaced and new ones appeared in their place.

However, not everything went well. The division of work among many entities greatly extended the implementation time. This was favored by poor regulations and tedious procedures. In addition, potential subcontractors were not keen on undertaking additional tasks, and those that are subject to high technical risk. Interventions at the ZPLiS level were often necessary, and if the cooperating party was outside the aviation industry, then at the level of the Ministry of Metallurgy and Machine Industry.

In mid-January 1980, the Institute of Aviation placed an order dated November 1979 at OBR SK Mielec for the production of three prototypes and one for static tests. All planes in the basic two-seater version. The first plane was to be completed in mid-1981, and the last in mid-1982.

The final agreement was signed at the end of June 1980, and was a four-party agreement; ordering ZPLiS - IL, recipient of STL MON, contractor OBR SK Mielec, implementing WSK PZL Mielec. The contract did not cover the target number of aircraft. This was to be specified in a separate implementation agreement. The contract also made the whole program more realistic; it extended it by half a year and increased its funds almost twice. There was invisible inflation. The contract was also structured in such a way that it gave the opportunity to annually adopt an annex as to the material scope, dates and costs.

In mid-May 1980, in OBR SK Mielec, an order was issued for the technical preparation and implementation of prototypes of the "300" product. This symbol has permanently entered the Program. The command also specified the serial numbers of prototypes, in accordance with the numbering system specified for ZPLiS; 1 ANP 01-01 - for static tests, 1 ANP 01-02 to 04 for flight tests.

To streamline the task, the General Director of ZPLiS issued an instruction to subordinate entities regarding the commissioning of components and components for the aircraft. This command was to eliminate problems with cooperation. However, his power was illusory. The command-and-control economy has perfected the avoidance of difficult tasks. While in the normal world, companies are fighting for government and / or military orders, in Poland at the time it was not so favorable. This resulted, among others, from the reluctance of companies to improve the quality of their products. It was said then that the customer would buy everything. And special production was subject to high quality control.

Beginnings of stage D. 1980.

Stage D included flight tests and tests. The contract for this stage was already signed in the mid-1980s, and had a strange arrangement due to the existing regulations; ordering ZPLiS - Institute of Aviation, recipient of STL MON, contractor Institute of Aviation - Scientific Division. The signing of this contract did not mean that the research would start immediately, but it allowed the preparations for this stage to be started by commissioning certain activities. And so in September 1980, the Institute of Aviation placed an order in Mielec for carrying out strength tests.

Further work on the Iskra-22 M aircraft.

At the end of May 1980, new data on the development version of the aircraft, i.e. the Iskra-22 M, was sent from Mielec to the Institute of Aviation. They stated that the aircraft must have a new wing. The technical design was to be completed in mid-1984, two prototypes in 1986, aircraft testing by the end of 1988, and implementation in 1989.

New five-year planned. 1981-1985.

The approach of the new five-year-old made the topic of the combat-training aircraft more realistic. But the changed socio-political situation caused paralysis that was difficult to determine. Party power behaved as if nothing was happening. But at lower levels there was already an irresistible desire to improve and bring dreams closer to reality. The coordination plan for nodal problem 12.05 for 1981-1985 already included partial changes. The deadlines for closing the basic stages have been clearly extended; stage B until the end of the third quarter of 1981, stage C until the end of 1983, stage D until the end of 1985. Costs have increased and not just inflation. The trial batch of the basic version was determined for 10 aircraft.

The Iskra-22 M aircraft was treated as a separate topic and marked with the symbol 12.05.02. New dates were set for him; study until the end of 1983, preliminary design until the end of 1984, technical until 1985. One prototype for endurance tests and three volatile are planned. The trial batch was supposed to have 20 aircraft. It was clearly stated that this is a new aircraft, although the starting point is Spark-22. As a drive left the K-15 engine built under the topic 12.05.03. Equipment for the development version is grouped in the topic 12.05.04. and codenamed Plajada-1.

Everything was clear and only had to be realized. But the economic crisis in the country, tense international situation and party pressure were not conducive to the development of the Program. Ten years later, many people whose wave of transformations took them to high state positions and who made important decisions (also for Iryda and Sokoł) do not want to remember that anymore.

At the beginning of January 1981, another meeting of stakeholders took place in Mielec. The deadlines for prototypes were adjusted on it. WSK PZL-Kalisz was recommended to help WSK PZL-Rzeszów with the Kaszub-15 engine components. It was recommended to conclude contracts with CCCP for finished products as soon as possible. In the new five-year plan, stage B was no longer present, so it was considered completed, and the unfinished sub-topics from stage B were hidden in stage C. Therefore, a slogan appeared, to supplement the technical documentation. As for the remaining deadlines for the completion of individual works, even stronger pressure continued to appear, mainly from the Ministry of National Defense. The military side even talked about two years of delays.

As for the military side, the reader could get the impression that military contracting authorities were the main cause of difficulties in the Combat-Training Program and they were so urgent and adamant about the conditions of the WTT. But it was the Polish army that wanted Polish planes. General Sikorski did not have much room for maneuver. He was the great engine of the entire Program. An advocate of possessing native equipment and development of the Polish defense industry. On the other hand, he had to take into account Poland's obligations towards the UW (Warsaw Pact).

Project implementation conditions. 1981.

Sooner or later the project implementation had to hit difficult problems. The problems were sometimes very prosaic and often very serious. The first element was the lack of appropriate constructors' staff. Their deficiencies often resulted from ignorance about the machinery park at the disposal of Polish industry. For example, it turned out that the element they designed had to be divided in half at the factory, because the machine tools did not have such a large range. For example, there was no information as to the size of autoclaves used to cure composite materials. The possibilities of quick technical calculations, mainly strength calculations, were also strongly limited. There were no programs and fast computers. RIAD computers manufactured in Poland and available in Poland by IBM were not sufficient. The most important calculations were made by the Institute of Aviation for a fee on the UNIVAC 1106 computer in the Planning Committee of the Council of Ministers, when it was free, which was not often. This caused further delays. However, these were the realities and the consequences that resulted from them at that time.

As I mentioned above, stage B has been formally completed. However, as was known, a lot of work was still to be done, which was followed up to the next stages. As it turned out, it was over 44% of the contract value. These works were included in the annex to contract 73 / DK / 80 in the second half of 1981, specifying the completion of construction documentation, proof calculations, preparation of descriptive and operational documentation, supplementation of blowing in wind tunnels and preparation of ground equipment documentation. Whereas the annex to contract 10 / KOR / 80 for stage C in the second half of 1982. includes preparation of the documentation of the aircraft installation and equipment as well as refinement of the rest of the designer's documentation.

All this resulted in too large tabs in stages B, C and D, a deepening lack of financial resources, brightly visible organizational deficiencies and growing impatience of the Ministry of National Defense. Attempts were made to look for the guilty, and this led to additional conflicts, and worse, did not improve the situation of the Program. There was also an unusual situation. The prototypes were built and the Ministry of National Defense did not receive and approve the technical design. Decision makers knew everything.

As a result, by the end of 1981, in practice only the airframe's technical documentation had been completed. A large part of the complementary work was carried out at the Institute of Aviation, including aerodynamic blowing. The comprehensive execution of the designer's documentation for the installation and equipment has been moved by several months.

Technical preparations for building prototypes. 1981.

Preparation for the construction of prototypes required first of all drawing the plane structure of the aircraft. Until the end of the 1970s, this was done only by hand in the tracery, where the precision and experience of the tracers working there were crucial in terms of results and timelines. The aircraft had to be made with extreme precision in terms of external contours, where the permissible deviations are fractions of a millimeter. The interior of the aircraft had to be extremely carefully designed with the possibility of compensating for dimensional deviations during assembly. In turn, the equipment for making the airframe must be made to the nearest hundredths of a millimeter. This applies to molds, templates, holders, templates, mockups and assembly devices. The same applies to tools and machines used to build the aircraft. In order for the final effect to be satisfactory, this is the first stage, i.e. the disc drawing must be a five. The external and internal geometry must be "closed". Relaxing as to the deviations not only worsens the flight parameters, but even worse will cause the uniqueness of subsequent copies, the quality of which will decrease drastically.

At the Iskra-22 airplane, the NMG (numerical master geometry) system, a numerical mapping of geometry, unique at that time in the RWPG system, was used from the beginning together with devices from the Norwegian company Kongsgerg. It allowed to speed up the work and, above all, to achieve high accuracy in mapping the contours. And a direct transition to the implementation of individual elements on numerically controlled machine tools (OSN). The unique NARVIK system was used above. Kongsberg. Unfortunately, the changes made still in 1980, in the geometry of the aircraft made it impossible to take full advantage of the advantages of the new systems and fulfill the contract 10 / KOR / 80, by the required date by the end of 1980.

Incomplete design documentation of the equipment and installations prevented the final dimensioning of the airframe structure and geometry. This meant "only" delaying the Program and the departure of the prototype. A relevant annex appeared in January 1981. The era of reconciliation and mutual antagonism has begun. Mielec demanded that the Institute of Aviation make the flight of the first aircraft real in March 1984, justifying it with the lack of complete design documentation, delay in delivery of finished products and the prototype of the An-28 aircraft. The annex was signed in July 1981.

Already in June 1981, the first plate drawings of wings and tail were received. It was worse with the hull drawings. In addition, the final form of the inner hull changed due to equipment. As a result, the hull drawings were not completed until May 1982.

In the second half of 1981, another annex was signed. It corrects the costs and deadlines related to stage D.

Contrary to appearances, military outlets had a huge impact on the future aircraft. They received several important tasks to carry out; ITWL (development of operation and diagnostics systems and cabin lowering system, testing of combat properties and training), Military University of Technology (armament system, numerical testing of flight dynamics, testing of cabin guards), WITU (shooting system), WIML (laboratory examination of physiological issues related to pyrotechnic crushing the cabin cover).

Flutter testing was also carried out on a large scale, which was related to the machine's flight ranges. An agricultural aircraft M-15 was used at the Institute of Aviation for this purpose.

At the end of December 1981, an agreement was signed between OBR SK Mielec and the Institute of Aviation for carrying out static strength tests in Mielec of the I-22 prototype.

The dramatic martial law introduced by General Wojciech Jaruzelski for the nation and the Iskra-22 Program had additional negative effects. Organizational, cooperative, supply, human resources and financial problems deepened. The result is an increase in work delays. The Ministry of National Defense continued to seek to own a Polish modern aircraft. For this reason, the period 1982-1983, for the topic 12.05, announced significant decisions. Old PZL Lim aircraft were aging, but the desire to have a Polish aircraft at that time was certainly much greater than after 1989. It was sad.

The Ministry of National Defense assessed the Aircraft Technical Design. 1982 year.

On 1982-03-20, the Head of Aeronautics of the Defense Ministry general M. Sikorski signed an order that appointed a team of military and civilian specialists to evaluate the design of the Iskra-22 aircraft. The committee had 31 people, only 3 civilians. The chairman was Col. prof. Dr hab. Inż. Z. Dżygadło from WAT. His deputies were Col. M. Sc. A. Milkiewicz from DWL and Col. M. Sc. Z. Prochot from STL MON. The team made an assessment in April 1982 and the protocol was signed by Gen Sikorski. The commission completed work on 1982-05-05 and the protocol was approved in July 1982.

The most important was that the technical design in the implemented scope gives the possibility and purposefulness of continuing the construction of prototypes. The Commission made several comments, and most of them were known; supplementing the designer's documentation, supplementing calculations, mainly strength ones, lack of operation and training system, it was not possible to assess the perspectives of the Program in terms of the development version, it was necessary to develop and implement for production finished products, mainly avionics under the Plejada-1 program and new materials, e.g. alloy A 357, maraging steel and cast steel as well as PA 7 alloy with increased purity.

Detailed project assessments resulted in specific comments and conclusions; The airframe's curb weight is in the upper part of the statistical data compartment for this class of aircraft, but its deterioration is to be expected. Most of the WTT performance data from 1980 will not be obtained. The materials used in the airframe are not modern, with a few exceptions. Due to the organization used, the technical documentation has yet to be corrected, which has a negative impact on deadlines. A large number of requirements for aircraft equipment and cabin ergonomics require the implementation of another model in a 1: 1 scale.

The committee's assessment of the aircraft itself was the most correct. Organizational conditions were correctly assessed. Comments on the materials used have already been raised by the commission assessing the preliminary design, but the desire to improve on this topic was only unrealistic wishes.

Fictitious plans and the actual state. 1982 year.

In 1982, the scope of work and their deadlines, as usual, were imposed from above, at the highest levels of the party. Resolution of the Council of Ministers No. 258/81 of 1981-12-11, specified the plan of directive tasks under the Central Socio-Economic Plan, and No. 278/81 of 1981-12-30, the program of production, supply and provision of services for country defense. The next resolution of the Council of Ministers No. 36/82 of 1982-02-09 set out a supply plan for national defense in 1982. As a result, it confirmed the construction of the Iskra-22 aircraft, Kaszub-3 W 22 and Kaszub-15 engines. The resolution maintains the flight date of the first prototype at the end of 1982. Other topics, including the Iskra-22 M, had the rank of a department, which in the realities of the time meant that they could not be successfully completed due to the economic situation of the country.

"Economic reform" was carried out during this period. This means a new organization of the socialist economy. In place of ZPLiS and ZWSLiS, the Association of Aviation and Engine Equipment Manufacturers. Directives related to the implementation of resolutions at the beginning of April 1982 flowed into this entity. The dates were obviously abstract, but they were, and the ZWSLiS management had to comply with them. However, the matter seemed simple, because at that time many workplaces were militarized and additionally bet by military commissars, and in many cases supported by combat troops. In Mielec the canteen was turned into barracks for soldiers guarding employees.

During this difficult time, in October 1982, an annex was signed between the Institute of Aviation and Mielec to complete prototypes in September 1984, and costs increased by 23%. An interesting fact is that the 21st Military Representation at WSK Mielec did not agree and did not sign under the annex, standing firmly on the deadlines imposed by the government. But at the same time, it told its superiors that deadlines were unreal. Everyone was aware of the unreality of plans. The directors of individual companies felt the most, as they were the last in the entire decision-making chain. Representatives of ministries also joined the case by issuing relevant orders, in which they "demanded to use all means to make up for delays". The attorney, of course, issued an identical order to the Chief of WSK Mielec, M. Rycz, MA, "asking him" for personal supervision.

The case was similar in WSK-Rzeszów, whose representative informed the ministry that Kaszub-15 prototype engines, in the number of 3 pieces, would be made only in 1985, because currently they are busy with equally important production for CCCP, namely 1 500 pieces of PZL-10 engines S for An-28 aircraft. 250 instrumentation items for the production of Kaszub-3 W 22 engines and 1,310 instrumentation items for the production of Kaszub-15 engines were waiting for implementation.

Due to the "delays" of the Program, at the beginning of August 1982, Gen Modrzewski ordered that BUSS (Special Equipment Activation Office) at MHiPM (Ministry of Trade and Machine Industry) carry out an analysis of the state of development of Program I-22. The analysis developed by this office was the first external evaluation of the Program status and certainly served as a basis for further decisions. And there was something to decide because the plans provided for the production of 250 machines. BUSS has developed its analysis based on existing documents and the visit of the main project implementers. According to the analysis in mid-July 1982, the technical design was 91% advanced, the technical documentation of the installation and equipment was being completed. Naturally, the construction of prototypes had to be less advanced. In the juxtaposition of work progress and anticipated dates it was obvious that meeting them was unrealistic. In conclusion, the analysis confirmed the actual state of implementation reported by individual entities.

The desire of the Polish Army for new equipment was increasing. It was caused by the rapid crumbling of operated aircraft. Analyzes carried out at the Ministry of National Defense in 1983 showed the need to have already in 1988, 20 Iskra-22 M combat aircraft, and in 1990, already a minimum of 90 machines. This was mainly due to the obligations imposed on Poland by participation in the Warsaw Pact. This situation confirmed the continued continuation of the Iskra-22 M Program as soon as possible. This was a difficult situation, since in 1983, no design work was started on the Iskra-22 development version, and the anticipated serial K-15 engines were available in 1991.

However, the Polish Army could not wait any longer. The documents existing at that time showed that if by 1987 the armed forces did not receive a minimum of 30 aircraft per year, in the basic version, they would start searching for aircraft abroad and completely resigning from the Polish project. On the order of the Ministry of National Defense, another study was carried out regarding the status of work on the subject of Program 12.05, including projects I-22 / Kaszub / Plejada. The situation was very dangerous for the Program. The Defense Ministry's arguments were very strong. Talks were already underway at the time to acquire heavy Su-22 attack aircraft with relatively high capabilities. There was also no doubt that the army first wanted to obtain a combat aircraft to replace the outdated PZL Lim aircraft, and then a new generation training and training aircraft in the PZL-130 training system - PZL I-22.

Fortunately, the result for the topic of Program 12.05 was positive under several important conditions. Changes were made to the Coordination Plan (for 1983-1985), which was adopted in June 1983 by the Council of Ministers. Once again the number of machines for the army was changed; 70 Iskra-22 and 170 Iskra-22 M, plus 10 trial batch machines. It was also assumed that the program to build the "Iapetus" aircraft simulator and the diagnostic and maintenance complex would be started.

In 1982, starters were also obtained from France for the Iskra-22 Program.

Change of the name Iskra-22 to I-22. 1983 year.

In 1983, without special reflection, the name of the aircraft changed from Iskra-22 to the designation I-22. It was associated with the creation of new documents, in which Iskra-22 was not already written, but only I-22 and so it remained. In the WSK PZL-Mielec, the designation Product-300 was still used. In 1984, Program I-22 received the official name "Iryda".

At the end of 1983, the Ministry of National Defense approved the improved technical design of the aircraft, according to which prototypes were built.

Engines. 1983 year.

At the end of 1983, the first Kaszub-3 W 22 engines were delivered from WSK PZL-Rzeszów. However, the Kaszub-15 engine program was still very delayed. It was even proposed a program that we could specify as a replacement program, namely to use the PZL-7 engine with a 1,400 kG thrust to drive the development version, which is a slightly modernized SO-3 W engine with the TS-11 Iskra. The modification consisted of adding a compressor stage. In addition, all flying TS-11 Iskra were planned to be equipped with these engines. However, this solution was considered too low-perspective and late. There were opinions, however, that this simple modification with the simple design of the SO-3 W engine alone will allow the resignation from further construction of the K-15 engine and allow to proceed to work on a modern two-pass engine, by default D-18. As a result, the I-22 and I-22 M aircraft will achieve their planned performance at WTT faster and at lower cost.

Qualification tests of the Kaszub-3 W 22 engines, which received the changed name K-5, were carried out at the beginning of 1984, and were recommended for serial production.

The single-flow Kaszub K-15 engine achieved a start thrust of 1,472 kg. It was developed by the Institute of Aviation and built by WSK PZL-Rzeszów. Work on it has been carried out since the mid-70s. The main constructor was until 1979, eng. A. Wierzba, and then eng. J. Fałęcki. 11 prototypes were built, the first of which began ground tests in January 1985, and flight tests on a flying dynamometer, for which the passenger aircraft Jak-40 was used, in February 1985. By the end of the R&D stage in Rzeszów, 30 K-5 engines were built.

I-22 aircraft prototypes. 1984 year.

The first prototype No. 1 ANP 01-01 was built since 1980 and was completed at the beginning of 1984. The aircraft was used for static testing. A little later, the first prototype for flight tests was completed, No. 1 ANP-01-02 nb 02. Modifications and modifications were still carried out on both machines. It was planned until the end of 1986, build five prototypes (1 ANP 01-01 - 05), and by the end of 1987 (finally built until March 1988) build 7 aircraft of the second trial series (1 ANP 02-01 - 07). So a total of 12 aircraft were built.

Resolution No. RM 154/84 of 1984-11-23, ordered in 1985 to end static tests of the prototype 1 ANP 01-01 nb 01, and tests in the field of volatile properties and performance of prototypes 1 ANP 01-02 and 1 ANP 01 -03. It was also ordered by mid-1985 to complete prototype 1 ANP 01-04 and submit it for qualification and state tests. Of course, this approach resulted in pressure to speed up the work, which unfortunately, as it turned out, badly affected the peace and compliance with safety rules in flight.

Flight of the PZL I-22 Iryda prototype No. 1 ANP 01-02 on 1985-03-05.

I-22 nr 1 ANP 01-02. 1985. Photo of LAC
I-22 nr 1 ANP 01-02. 1985. Photo of LAC

Aircraft I-22 No. 1 ANP 01-02, still without board number 02. Photo taken at the beginning of 1985, in Mielec, before the first flight. The photo was published in August 1986 in the press.

At the end of February 1985, aircraft 1 ANP 01-02 nb 02 received SP-PWA registration in accordance with regulatory requirements and obtained permission to start flight tests. SP-PWA registration was not painted on the plane.

As for the date of the first ANP 01-02 prototype flight, there are discrepancies in the sources. Two dates are given; 1985-03-03 or 1985-03-05. But on 1985-03-03, it was Sunday and it is unlikely that the flight would take place on Sunday. Tuesday is the most likely.

The first flight on 1985-03-05 was made by Eng. Ludwik Natkaniec. The flight lasted 40 minutes and was successful. In the first flight, imperfections in the control system were detected, which had to be removed.

By the end of March 1985, nine flights had been carried out, which confirmed the changes carried out and the need for further modernizations that were already expected before flights. The main problem was in the horizontal mouth. Its location and adopted division into the fin and rudder in the ratio 59% to 41% of the chord was a source of problems. During flights, it turned out that with wing flaps tilted more than 30 degrees, the plane is statically stable with the stick held, while after releasing the stick its stability is neutral. When leaving the circle with the flaps released and engines for full thrust, there was a lack of elevator rudder. During maneuvers with overload, the forces on the stick were much higher than recommended in the regulations. It was also found that with the aerodynamic brakes deflected high vibrations generated by swirled air jets. One more serious problem has been detected. While engines operating on the ground, fatigue damage occurred in the rear fuselage structure caused by engine acoustic loads (noise). These damages consisted of rivets loosening, especially the elevator. This type of defect was only found on the ground with the engines running. In flight, the flowing air reduces noise to a level that has no effect on the structure.

At the same time, the entire cycle of earth and fuel and hydraulic installations was completed. The latter contractor was PZL "Hydral". On the SB Lim-2 aircraft with a model of the I-22 cabin, the launch of Czechoslovakian ejection seats VS1-BRI / P was investigated.

Mock-up of the I-22 cabin on SB Lim-2 aircraft used for testing the rescue system. 1985. Photo of LAC
Mock-up of the I-22 cabin on SB Lim-2 aircraft used for testing the rescue system. 1985. Photo of LAC

In April 1985, plane 1 ANP 01-02 nb 02 made 3 more demonstration flights for VIP who wanted to finally see the secret product of the Polish Aviation Industry. This aircraft then returned to the factory to make the necessary modifications, which were completed in September 1985 and the aircraft was again subjected to flight tests. By January 1986, another 43 (other sources cite 32) flights had been made. The first flights made by the aircraft were successful, but they overshadowed the need for further amendments.

At that time, I-22 Chief Designer was in the heat of criticism. He was accused of insufficient operability in solving the difficulties associated with the closure of the aircraft concept. This opinion was unfair and testified that the PZPR party was looking for a scapegoat for its inept rule.

I-22 aircraft for India. 1985.

In mid-1985, a Polish military delegation in India submitted an offer for I-22 aircraft. The offer was not without chance, and it was supported by the operation of 40 TS-11 Iskra aircraft in India. The Indians expressed great interest in the plane. The contract was not concluded.

Further work on the I-22 aircraft. 1985.

In mid-1985, assembly work continued on the next two prototypes, 1 ANP 01-03 and 1 ANP 01-04. Static and dynamic tests carried out on airplanes showed that the expected increase in the curb weight of the aircraft would increase the allowable loads of individual elements by 12-15% from those initially assumed. It resulted from the fact that some airframe areas already needed strengthening. It was so with the wing. They were made as half-shell, but during rigidity tests due to the thickness of the girders and stringers' walls used, they behaved almost like a crust. It was damaged within limits higher than the plasticity of the materials used, almost without prior signaling of impending destruction. Fortunately, this defect only required local reinforcements. This situation confirmed that the simultaneous implementation of the technical design and construction of the prototype was not a good solution.

At the end of June 1985, the seventh and, as it turned out, the last annex to contract 10 / KOR / 80 for prototypes were signed. The trial time was extended and the financial value of the contract increased by 8.5%.

The end of 1985, he announced the arrival of another five-year socialist planning. A new Coordination Plan had to be developed for 1986–1990. It was approved and introduced very large changes to Program I-22. According to the new plan, the coordinator of projects 12.05.01 under the theme 12.05 became WSK PZL-Mielec, which was right. It wasn't until 1987 that an appropriate agreement was signed between the Ministry of National Defense and WSK PZL-Mielec for the design and implementation of the basic version of the I-22 aircraft.

Iryda at the threshold of a new five-year-old. 1986-1990.

Take-off to the first flight, on 1985-03-05, of prototype 1 ANP 01-02 nb 02 initiated the most important stage of research. It is time to verify what was created on the boards of designers, laboratories and studios.

Preparation for the next five-year (1986-1990) began in 1984, when the government approved the aviation industry development program until 1990, and it was the basis for developing the PKPW project 12.05.

The works were carried out in accordance with the adopted project work schedule. This plan took its final form and was agreed with all entities in March 1985. At that time, the Council of Ministers developed a new strategy in the field of scientific and technical progress and implementation of new technologies. Among others, directives were issued that were to improve the control of nodal problems in all B+R and W (research and development and implementation) works. I guess no one thought at the time what confusion would arise in the principles of financing works (B+R and W) of research and development and implementation works.

We also need to know that, compared to world prices, the implementation of the I-22 program was much cheaper. In the field of research and development (B+R), during the period from the beginning to the flight of the prototype (according to the dollar to PLN exchange rate at the time), it cost 5 times less than the Japanese Kawasaki T-4 training aircraft project, which was and the structural system was similar to I-22. By the end of 1984, less than 54% of the planned financial resources had been spent on Program I-22.

On 1985-06-16, the director of ZWSLiS issued an ordinance regarding the improvement of coordination of the I-22 Program. It was the first formal step to transfer the program from the Institute of Aviation to WSK PZL-Mielec. WSK PZL-Mielec was also to obtain the right to fully conduct stage D and the right to make any changes, subject to consultation with the main constructor. The directors of IL and WSK PZL-Mielec presented the findings for approval to the director of ZWSLiS.

Further tests of the prototype 1 ANP 01-02 nb 02. 1985.

At that time, the first volatile nb 02 prototype was undergoing modification. Work was carried out on installations and equipment. Local reinforcements resulting from strength tests were also introduced. Due to the vibrations of the structure, detected during the flight with the wing flaps swung out, limiting their swing to 30 degrees was introduced until another good solution to the problem was found. The front chassis with a better shock absorber was also replaced. In June, the team of the Institute of Aviation in Mielec conducted resonance tests nb 02. It was the first time in Poland that the research was conducted on such a large scale.

The first flight, after modernization, nb 02 made on 1985-09-02, and coincided with the introduction of the annex to contract 73 / DK / 80 for 1985. The annex was conditional because there was no final approved schedule for Stage D. Lasting until early January 1986, the flight test phase closed with 43 flights in 40 hours.

At the end of 1985, tests were launched to launch the VSI-BRI / P chair through the glazing of the first cabin on the SB Lim-2 model. This was done at a speed of V-150 km / h and at a height of H-0 m.

Modifications of the nb 03 and 04 prototypes were larger and therefore these aircraft were not completed by the end of 1985. Meanwhile, another package of changes was prepared for implementation in the summer of 1985, developed by the Institute of Aviation and OBR SK Mielec. However, it was necessary to develop a technical design, so implementation of the package was postponed to the next year. This meant that the final completion of subsequent prototypes would shift. In addition, some changes should be verified in flight on the prototype nb 02. In this situation it was unrealistic to complete stage D by the end of 1985.

In autumn 1985, a few major changes were started. One of the major topics was the horizontal tail, with a negative rise of -6 degrees. This change was to improve the stability of the aircraft, especially with a higher "Ma" number. In March 1986, three sets of height controls were made, with different mass balances. In this way, they wanted to reduce the power on the joystick. Another change was the new aerodynamic brakes. They wanted to obtain a greater distance of their lower edge from the hull in the open position, so that the air in this region freely flows and does not disturb the flow of the rear part of the hull so much. The solution used, however, reduced the surface of the brakes, and thus their effectiveness. New main wheels have also been developed that are more durable and have more effective brakes. This was necessary because the predicted mass of the aircraft increased significantly. In November 1985, production of wheels for nb 02 and 03 was launched. The prototype nb 02 was to fly with the first main wheels until their service life was exhausted.

Already in 1985, it was known that in 1986, after completing the full series of static and strength tests, the I-22 nb 01 aircraft was subject to further modifications.

Case development version of the aircraft. 1985.

Issued WTT conditions and suggestions of the Ministry of National Defense clearly indicated the need for the Polish Army to obtain a development version. It was to be primarily a tactical support plane and possibly training, which was mainly to be implemented by the basic version. In accordance with the requirements of WTT, the I-22 M aircraft were to be built based on the basic version airframe. For various reasons, the Institute of Aviation has not submitted any draft development version. It was already clear that the I-22 M would be a new aircraft outside the overall system, as mentioned above.

The Iskra-22 M program was officially included in topic 12.05 for 1981-1985, as topic 12.05.02. But already in the revised plan for 1983-1985, the reality of the topic on 12.05.02 was already small. Our economy was unable to sustain two Programs. The general development line of the I-22 aircraft was presented by the director of ZWSLiS and the deputy minister of MHiPM, Gen Modrzewski, presented in May 1983, and was a confirmation that I-22 and I-22 M were different planes. However, the possibility of an intermediate stage was signaled, namely the emergence of the I-22 airframe with K-15 engines, defined as the basic reinforced version. The I-22 aircraft, possibly manufactured, would have been modernized to this form until 1988, and since 1989 the production of new machines would have started. However, the target aircraft I-22 M, with a new airframe, meeting the requirements of the WTT, in the form of a trial batch, would appear in 1989. Further on, other utility versions of the aircraft were to be created (1990-1995); one-seater clean, reconnaissance, with no specified number of crew, towing. The development line presented was very logical. But the verified topic of 12.05 did not contain any sub-topics of the type, i.e. the basic version enhanced.

In July 1983, a study entitled "Concept and development of the I-22 training and combat aircraft" was written by the main designer of the I-22, Dr. Eng. A. Baron. An agreement was broadly sent to interested entities discussing the signaled development line together with the proposed implementation deadlines. It stated unequivocally that in order to meet the WTT requirements of 1980, the aircraft would receive a wing with a much larger bevel, extensive mechanization, greater load and new profiles. A new mouth will be needed. Horizontal, probably plate. Control system at least partly automated. The fuselage was to remain the same.

By the way, inaccuracy was found in WTT conditions regarding the maximum speed and the allowed number "Ma". The Ministry of National Defense relied on American standards. Permitted Ma = 0.95, while meeting US MIL standards, and this meant V maximum = 1,050 km / h. To meet this should be Ma = 1.05, i.e. above the speed of sound. As a result, it's a completely different plane.

The development line was divided into four stages;

  • Ongoing modernization and improvement of the basic version I-22.
  • Based on the I-22 building a reinforced version of the I-22 W and single-seat I-22 WB.
  • Development of a development version meeting the WTT conditions in the two-seater I-22 M variant and the one-seater I-22 MB variant.
  • Based on the development version of the reconnaissance version of the I-22 R, and based on the I-22 towing version of I-22 H.

The comparison of terms and costs for the proposed concept must have been a shock to contemporary decision-makers. The imposed dates did not even include the I-22 W version, the implementation of which was noticed the availability of K-15 engines. Version I-22 M would be created five years later than assumed. And so it was optimistic, given the crisis prevailing in Poland, the end of which could not be seen. Interestingly, it came to a good assessment of the costs of individual stages and can be considered real. All on the assumption of no delays. But for now, in the subject 12.05 (PKPW12.05) for 1983-1985, on the subject I-22 M, only 23% of the funds calculated by the interested parties were allocated.

The creators of I-22, learned from experience, assumed several important conditions that were intended to avoid similar problems in the implementation of the subject I-22 M. There were to be tabs of individual stages. Aerodynamic tests, mainly tunnel blowing, should be carried out at the preliminary design stage. They were to provide the basis for the aircraft's geometry. The start of construction of the prototype only after the technical project was closed, and not as it was at I-22 and already in 1983, was very visible.

Equipment was to be a success for the I-22 M aircraft. It was found that "Plejada-1" did not bring the expected results. Construction of own radar station was proposed. Its prototype was to be created in 1989. Automatic SASS control system, autopilot completed in 1995. Warning system, with active WRe measures ready 1987. On-board computer in 1988. Radio-technical near navigation system in readiness until 1990. Active response system with telemetry system. HUD head-up indicator. It required huge expenditures and did not guarantee success. To increase the chances, it was also proposed in individual projects to introduce staging and secure substitutes. For example, a laser rangefinder with CCCP from Su-22 M 4. As life has shown, the plans for these devices and systems were just wishes.

When designing the I-22 M, it was a mistake to lower the airfoil to reduce aerodynamic drag. However, this was due to too optimistic thinking about the low mass of the empty plane. The weight of the equipment would be so large that even extensive mechanization would not allow a sufficiently long run during take-off. Where's the armament?

In addition, the powertrain was still imposed from above. Therefore, not all conditions of the WTT project I-22 M would meet. The constructors made this clear. For example, a radius of action would not be reached. It was suggested to improve the propulsion system by adding another compressor stage to the K-15 engine or building a D-18 double-flow engine with 2 x 1 800 kG thrust and dimensions not larger than the K-15 engine. If the construction of the D-18 was started it would have been ready in 1995 for testing. However, taking into account the analyzes carried out, the aircraft should have a power train with 2 x 2,500 kG take-off.

The concept of I-22 development was constantly analyzed by various entities, but without specific effects and conclusions. As a result, no relevant orders were placed. Well, costs and deadlines were awake and nobody was in a hurry. The I-22 M program existed virtually. A lot has been said about this, but no documents have been created that would move the work forward. Half a year has gone forever. In mid-1984, the Institute of Aviation was obliged to develop the concept of the I-22 M aircraft, at the same time it was ordered to develop a documentation program and prototype of the I-22 with K-15 engines, i.e. the basic enhanced version. As there were no further contracts for this, so in practice the work on I-22 M and I-22 W did not go forward.

The drive problem returned very quickly. The first prototype of the K-15 engine from WSK PZL-Rzeszów was not submitted to tests at the Institute of Aviation until January 1985, and two more engines were in the final stage of assembly. In addition, in mid-1984, WSK PZL-Rzeszów presented a project of a competitive single-flow engine PZL-7, with a thrust of 1,350 - 1,400 kg. It was a modified SO-3 W 22 engine with an additional zero compressor stage and could be used for both I-22 and TS-11 Iskra aircraft. The main advantage of this engine are costs 60-70% lower than the costs of developing K-15 engines and availability within three years. Eight prototypes and completed stand tests were proposed. Good idea, but five years late. You should then delete the K-15 engine and start everything from the beginning. Although WSK PZL-Mielec expressed its benevolent interest, the Ministry of National Defense was not impressed. In the absence of funds and topics already started, which was known to be positively completed, the PZL-7 engine program was superfluous.

At the beginning of 1985, the Institute of Aviation was instructed to start the preliminary project of the one-seat variant I-22 M. Because this topic was only of departmental, not governmental nature, it was practically not implemented.

During this time, the concept of I-22 development has changed again. The single-site developmental version became a priority, and the two-site development version was not to be created at all. The two-seater version was to be used only as a reinforced basic one and as a training and combat one, with K-15 engines. The single-site development version was given the topic number In addition, there were two sub-topics; 12/05/02/02 - diagnostic and service system implemented by the Institute of Aviation and Military University of Technology, 12/05/02/03 - studies and research on further improvement of the assault plane and the use of D-18 double-flow engines.

In the draft R&D work plan for 1986, subject 12.05.02, deadlines were specified. Studies to mid-1986, preliminary project to March 1987, R&D works to 1992, implementation in 1993. In turn, for the sub-topic; until 1986, - preliminary project, until 1992, - completion of R&D, implementation in 1995. By 1990, the sub-theme was to be implemented.

I-22 M prototypes were to be made in 1988-1991, which the army did not want to accept.

As for engines, in WSK PZL-Rzeszów in 1985, work on the prototype of engines No. 2-5 was advanced in 90%, and the next six engines No. 6-11 were to be built in 1986, but it was difficult because during tests at the Institute of Aviation, the K-15 engine prototype failed (combustion chamber). It required additional changes and construction works as well as repair of a damaged engine.

A little later, in the second stage new dual-flow D-18 engines were placed.

LSS (light attack aircraft) project. 1985.

At the end of November 1985, the draft WTT conditions for light attack aircraft (LSS), which was the I-22 single-seat version, was submitted for opinion and agreement. The Kaszub K-15 engine is intended for the drive. The performance was to be as in the WTT 1980 conditions, except for the maximum speed at 0 m, which was reduced from 1 050 to 980 km / h. The armament was to be made up of 1-2 Śniardwy multi-barrel cannons with a supply of 600 rounds, and in the event of its unavailability, GSz-23. 2,000 kg armament on six nodes. The equipment was to be significantly expanded. The aircraft was to have the features of a combat machine, such as self-sealing tanks, armor of critical components and crew, duplicate systems. The aircraft was to be the base of a two-seater reconnaissance aircraft. Interestingly, the reconnaissance operator would occupy the first cockpit and the second pilot.

The project repeated two errors. The required high performance cannot be achieved with a imposed string of 2 x 1,470 kg. Secondly, that the LSS will be a simple modification of the existing I-22 aircraft. Specialists from Mielec immediately stated the impossibility of creating LSS on the basis of I-22. Comments were forwarded to the higher authorities. It reached the Ministry of National Defense and at the meeting of the Thematic Council of Experts on LSS some amendments were introduced; the number of plots was limited to one, the weight of suspensions increased to 2,200 kg with a 3,000 kg perspective, extension of the assault-reconnaissance variant with controls in both cabins, addition of p-z class weaponry and introduction of two stages. The changes were significant, but they brought changes in terms of engine-performance-mass, even made them even worse. Discussions were held to shape the WTT for the LSS I-22 M (Iryda-MS) aircraft, which should be approved in June 1987, after the preliminary project has been completed. It was still clear that I-22 MS would be built on I-22.

The General Contractor of the I-22 MS project was the Institute of Aviation, which meant an organization identical to the I-22 project. From the perspective of several years, it is almost certain that hardly anyone believed in the success of the I-22 MS program, and not even for technical but financial reasons. The crisis in Poland has deepened.

Further work on the I-22 aircraft. 1986.

The change of general contractor for the I-22 program introduced at the beginning of the new five-year period caused a lot of confusion and caused a vacuum for some time. It was necessary to conclude a new general contract and contracts for individual stages. Now, the ordering party has become MHiPM (Ministry of Trade and Machine Industry), and the general contractor is PZL-Mielec. Of course, the main problems appeared on the financing lines of individual stages of the Program. The three-month exchange of correspondence between interested parties led to the fact that everyone should settle accounts for the work carried out by the end of 1985, and in addition it turned out that for the Institute of Aviation, the entity WSK PZL-Mielec is the same as OBR SK Mielec. It was explained that the tangible works carried out by the end of 1985 are to be settled according to old contracts, and new and those which were not completed by the end of 1985, according to new contracts. In December 1986, the Supreme Audit Office (NIK) began the audit at WSK PZL-Mielec. Its main goal was the Iryda Program. The audit only confirmed what everyone already knew. The extension of the Program was caused by the adopted organizational structure and delayed deliveries, mainly from abroad. It wasn't until December 1986. agreements were signed between OBR SK Mielec and the Institute of Aviation (135 / EU / 86) and between OBR SK Mielec and WSK PZL Mielec (OKF-14/38/86). General agreement 2 / U / TP / 86 was signed on 1987-01-17.

To sum up, due to the organizational disorder of the supreme authorities, Program I-22 got an annual slip and was to be implemented as soon as possible.

By the end of February 1986, nb 02 had 7 more flights, followed by preparation for the second stage of flight tests.

During this time (beginning of 1986), the airport runway in Mielec was renovated. Therefore, the nb 02 aircraft was transferred to the airport in Radom, where further tests were carried out. During these tests, the horizontal tail was replaced by a negative elevation of –6 degrees. The second stage lasted almost until the end of May 1986, and closed with 32 flights in over 42 hours.

Flight tests of the nb 02 prototype are only part of the Program, whose final shape was still relatively distant. WSK PZL Mielec intervened many times in ZWSLiS regarding the inclusion of the omitted stage C (prototype construction). It was postulated that by mid-1986 the construction of prototypes nb 03 and 04 be completed, and their refinement as part of trials by the end of 1987. It was also considered necessary to extend stage D (flight tests) by six months. This caused the Chief Designer to be censored. On the part of the Ministry of National Defense, he was accused of low efficiency of operations. However, it seems that the main issue was the organizational matter. One should know that the Chief Designer was also the first deputy director of the Institute of Aviation and had other tasks as well. It is also no secret that for almost all designers from the Institute of Aviation Program I-22 was the first "real jet". People from the former Tadeusz Sołtek's team have long been gone in the aviation industry.

In March 1986, the construction of the nb 03 prototype was completed, but no modifications were planned, which was to be done by mid-July. The case from nb 04 looked slightly different, which already received a significant part of the modifications in production. This concerned, among others, the wings and the main landing gear. Finished products ordered from subcontractors were also waited, therefore its completion was planned for the fourth quarter of 1986. In addition, both aircraft were waiting for new sets of tailings.

Since June 1986, the nb 02 aircraft underwent modifications, the most important of which was to strengthen the rear fuselage and wing. The entire airframe has been verified to assess wear and capture weaknesses. It was decided to carry out verification on prototypes after every 50 hours of flight. These works were carried out at the airport in Radom by a team from OBR SK Mielec. At the beginning of August 1986, flights on nb 02 resumed. At that time, preparations for flutter tests, very difficult and dangerous, were far advanced. In mid-September 1986, the aircraft received a new horizontal tail and further flights began. This flight test phase lasted until the end of October 1986, and had 52 flights in 64 hours. After its completion, the aircraft was again verified and received permission for subsequent flights. Now the main preparation for flutter tests has taken place.

At the time when nb 02 was flying in Radom, the construction of nb 03 and 04 aircraft stopped in Mielec. This was because the strength tests of nb 01 and wind tunnel blowing showed the need for local strengthening of the airframe structure. Both hull, tail and wings. It also turned out that the rudders should receive a third support.

During this time, there was a problem with the weapon control system. The concept and design were developed by WAT, accepted by DWLot (Air Force Command), and the Institute of Aviation became the contractor. Modified ASP-PFD-21 sight from the MiG-21 fighter to the ASP-PFD-I-22 variant was carried out by WZL Dęblin. The crosshair, logical block and other components formed the UWS system. Polish specialists have failed to set new algorithms. CCCP did not provide source algorithms. The sight therefore worked like in the MiG-21, which, with violent maneuvers, with an attack on ground targets made him useless. In turn, the newly developed Polish components were still imperfect. With stringent temperature, vibration and overload requirements, it was difficult to obtain parameter repeatability. As it turned out, the operation of the systems left much to be desired. The system was extremely emergency and became the weakest link in the Program. Despite this, on the nb 03 prototype, the UWS system was mounted and allowed to be tested with numerous restrictions, waiting for its refinement.

Flight tests of modified prototype # 1 ANP 01-02 nb 02 were generally assessed as positive. The plane was correct in flight. Comfortable and ergonomic cabins were praised. And the lack of engine power was felt, which did not allow to achieve the set WTT requirements. During tests, insufficient stiffness and insufficient strength of the rear fuselage and tail were found.

In mid-1986, the production schedule for the information series I-22 was approved; Two in 1987, six in 1988, and four in 1989 (producing six aircraft per year). In 1991, the annual production was to be 30 aircraft. At that time, the Council of Ministers ordered to start work on the export offer of the I-22 aircraft.

Written by Karol Placha Hetman

Kraków 2008-08-01

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