Lazarov Laz-12

 

Professor Tsvetan Lazarov was put in charge of the Department of Aircraft Engineering at the State Polytechnic in Sofia, where he kept with aircraft designs. Along with teaching and researching work, he made various designs like the Laz-9 (which we covered here ) the Laz-11 or a development of the Laz-8 with a more powerful engine, among others. 

The Laz-12 was a single-seat light-trainer aircraft designed by Prof. Lazarov together with other three of his pupils. Theoretically speaking, the Laz-12 was designed to train fighter pilots. It featured a completely retractable undercarriage, it was equipped with an RSI radio system (the same type that Soviet fighters employed) and was armed with two machine guns. The design of the Laz-12 was heavily based upon the Laz-7M and, after sending technical documentation, the construction of a prototype began in late 1952 at Plant No.14 at Lovech. 

The Laz-12 was a cantilever monoplane with a retractable landing gear and a low wing. Design was mixed: Wings were made out of wood sheathed with plywood and pasted over with nitrocellulose varnish. Tail planes were made out of wood covered with impregnated fabric. The fuselage was a truss of thin-walled steel pipes Duraluminium skin and canvas in different areas.

Although tail planes were similar to those of the Laz-7M, they had a smaller surface area. However, when tested, they had to be replaced with large-sized planes.

Flight tests were disappointing, as the aircraft didn't live up to its expectations, which forced them to make some changes like eliminating the machine guns and the radio system. This equipment removal saved the airframe 80 kg (176 lbs) at take off. In spite of these changes, performance was still far from expected, specially rate of climb and ceiling (5.500 m -18.044 ft- expected to just 3.500 m -11.482 ft- ) 

Testing was carried out with a fixed landing gear because they had to cope with a deadline and, therefore, the landing gear retraction system was not complete yet. Anyway, it's thought that even with the landing gear retracted, the Laz-12 wouldn't have achieved its expected numbers. The main reason for that failure relies on its weak engine which, with an increased wing load, it didn't yield enough power, so the test commission declared the aircraft as unpromising, further testing was cancelled and the only prototype was rellocated to Musachevo airfield, close to Sofia. Eventually both engine and avionics were removed to be used on the Laz-7M and the airframe was destroyed.

Although the Laz-12 was a failure, it took its place in the aeronautical history of Bulgaria, as many aeronautical students learned from its design.

 

Source:

 http://www.airwar.ru/enc/other/laz12.html (translated and adapted)

Lazarov Laz-7M

 

In the previous post we wrote about the Lazarov Laz-7, however, we didn't mention that, albeit a successful aircraft (relatively speaking) it was prone to various accidents caused by a nimble crankshaft in the Walter-Minor 6-III engine.
In order to cope with that issue the Bulgarian People's Army Air Force (BPAAF), which by the time of these events had already fallen under Soviet influence, ordered the replacement of the  Walter engine with a Soviet-made M-11FR, as they were, theoretically, equally powerful, more reliable and, furthermore, they had constant-speed propeller.
Although the engineers of DSF-Lovech (manufacturers of the Lazarov) were reluctant at first, they were forced to comply with the command of a higher authority, so some engineers got permission (among them prof. Lazarov) to go to Bozhurishte airfield, where, among many others, some Soviet Yakovlev Yak-12 were stationed, to study its propulsion system. 
With that knowledge gathered, a single Laz-7 (numbered as 68) was delivered to the aircraft factory at Lovech, where the Walter engine was replaced by the M-11FR in the Laz-7. 
In this configuration, that Laz-7 was test flown by test pilot Popganchev, with unsatisfactory results as the M-11FR engine, coupled with the light fuselage of the airplane, lost force really quick. 

After this failure, the BPAAF ordered the creation of a complete new aircraft, powered by the M-11FR engine and the features of the Laz-7. For this, they were given a very short deadline; by 1952 that aircraft had to be already being mass produced (all these events took place in 1951). So engineers had no time to make a scale model nor test it in the wind tunnel.

This time, design was tasked to eng. Kiril Karlov who took the same layout of the Laz-7, installed the Soviet engine and made some alterations to the wings to make them lighter. Some further changes were also made, to the point that Karlov asked permission to name this design as ZAK-1, petition which was rejected, as the design was directly based on the Laz-7, so the designation of Laz-7M (the letter standing for "modernized") was given instead.

The first test flight of the Laz-7M, with its characteristic star-shaped nose (similar to that of the Yakovlev Yak-18) took place on 16th June 1952 with satisfactory results. This was the first of a total of 102 flight tests which took place until the next month. In July the prototype was passed on to the Bulgarian 2nd Night Light Bomber Aviation Division, stationed at the town of Stara Zagoda, to undergo military trials.

In that unit it was used both as a day and night trainer but also as a ground attack trainer, as it had the same armament the Laz-7 had. However, in order to make it lighter, most of the times it flew unarmed, as it was easier to fly. 

A total of 150 Laz-7Ms were manufactured by DFS-Lovech and were employed mainly by the BPAAF's School, the BPAAF and some flight clubs until the early 1960s.

Apparently the Polish People's Republic considered ordering 100 machines, but they opted for the Yakovlev Yak-18 instead. Egypt also was one possible customer, as they considered ordering 50 Laz-7Ms in the mid-1950s. We have included hypothetical profiles for both countries.

Some few aircraft also flew with the DOSO (a civilian volunteer organization for the protection of the Bulgarian aerial space).

Sources:

1st http://www.airwar.ru/enc/other/laz7m.html (translated)

Lazarov Laz-7

 

The Lazarov Laz-7 was a Bulgarian two-seater liaison and trainer aircraft of the immediate post-war era.

Its inception can be traced to April 1946 when Yugoslavia invited Bulgarian aircraft designers, namely those belonging to DAR (the main Bulgarian airplane manufacturer back then) to take part in a design contest for a new two-seater aircraft powered by a light engine water-cooled engine capable of yielding 140-160 hp of power.

Designed by Tsvetan Lazarov, chief engineer of DAR, in Yugoslavia, the Laz-7 was a cantilever monoplane with a low wing, a fixed-undercarriage and a two-seat glazed cockpit with the pilot and the trainee/passenger/observer sitting in tandem. It was equipped with double controls and was almost entirely made out of wood, with the exception of the engine.
It was powered by a single Czechoslovak-made Walter-Minor 6-III water-cooled engine, rated at 160hp of power. 
On 20th August 1947 a production order was put and it wasn't until 10th June 1948 that the first prototype, Lazarov Laz-7.1 flew for the first time, with eng. Popganchev (a famous Bulgarian test pilot of the time) at the controls. 

After satisfactory flight-tests, the Laz-7.1 was sent to Belgrade, to honour the terms of the contest, and work on an improved variant, called Laz-7.2. This Laz-7.2 was equipped with an improved (and heavier) wing and was flight tested at the city of Karlovo, with almost identical results to those of the Laz-7.1. Those flights caught the attention of the Bulgarian Air Army and in August 1948 an order was placed for a two-seater trainer. However, as DAR was busy with another project, derived from the Laz-7, the Lazarov Laz-8, work on the Laz-7.3 (the production variant of the Laz-7) was delayed until May 1949, which made production runs to not be ready until September. 
The Laz-7.3 had every improvement the Laz-7.2 had and was equipped with a backwards retractable landing gear. When retracted, half of the wheel was left uncovered, feature which turned to be very useful in case of a belly landing. Unlike both Laz-7.1 and 7.2, where main pilot sat at the rear and the trainee at the front, in the Laz-7.3 the main pilot sat at the front, so he could have a better firing angle, as the Laz-7.3 was the first variant to be equipped with weapons. These consisted in two 7,7 mm M-30 machine guns mounted in the wings or one 7,92 mm T6-200 machine gun. It could also carry up to 120 kg (265 lb) of underwing bombs. The increased weight of the armament, spoiled flight characteristics, however, not enough to be rejected, so in June 1949 the Bulgarian Air Army ordered the mass production of the type.
The initial batches of the Laz-7.3 were still equipped with a fixed landing gear, but from the third production run onwards, the retractable landing gear was standardized. Some machines in the late production batches featured mechanical bomb release mechanisms, while others were equipped with pneumatic ones. Some very late models featured a different propeller, thanks to which higher altitudes could be attained. 
A total of just 160 serial Laz-7 were manufactured between 1949 and 1950 and served through the 1950s with the Bulgarian Air Force School and some other flight clubs. Some night light bomber regiments equipped the type too, mimicking Soviet night bomber regiments, typically equipped with the Polikarpov Po-2.

Sources:

1st http://www.airwar.ru/enc/other/laz7m.html (translated)

2nd http://www.aeroflight.co.uk/waf/bulgaria/af/types/lazarov.htm

Mikoyan-Gurevich MiG-19, Bulgarian users

The MiG-19 was the first Soviet supersonic fighter and it was exported to many foreign countries.
The first country it was exported to was Bulgaria. During late 1957 and early 1958 the Bulgarian People's Army Air Force (BPAAF) received 24 MiG-19S fighters, with the first 12 of them being assigned to the 19.IAP (Fighter Regiment) based at Graf Ignatiev Air Base, close to the city of Plovdiv.
A total of 59 MiG-19S and MiG-19P served with the BPAAF on four squadrons. The 11.IAP based at Gabrovnitsa Air Base, the 19. IAP, and the 10. IAD/21. IAP based at Uzundzhovo Air Base between 1959 and 1970. In some sources the retirement date of the last MiG-19 is set in 1978 as some MiG-19S were reconverted to the ground attack role by replacing their drop tanks with two FAB-250 bombs.
When the 11. IAP was disbanded in 1960 its MiG-19S and MiG-19Ps were transferred to the 18. IAP/ 1. IAE (fighter flight) based at Dobrostlavtsi Air Base, near the capital, Sofia. Additional second hand MiG-19Ps were acquired from Poland in 1966.
Some reports claim that there were also 12 MiG-19PM serving with the BPAAF, which were also acquired from Poland. That would make Bulgaria the first Warsaw Pact country to use the MiG-19 but also the last one to use the missile-equipped MiG-19PM.
In 1969 the MiG-19Ps that were still in service with the 18.IAP/1.IAE were upgraded with two APU-13 launch rails for K-13A missiles, making them the most heavily armed aircraft of the BPAAF with two NR-30, two ORO-57K FFAR pods and two K-13A air-to-air missiles. Those aircraft, known in some sources as MiG-19PT, served until 1975 and were sold, dismantled, to China.
Bulgarian People's Army Air Force's elite unit, 1.IAE of the 19.IAP often made practice interceptions against Soviet Tupolev Tu-95 and Tupolev Tu-16 bombers flying in high altitude training missions.
Given the complexity of the conversion training and maintenance difficulty of the MiG-19, some units retained their MiG-17F, which had still in the 1960s a good reputation of being a fast and agile dogfighter. The MiG-17F was used mostly for low-level combat and battlefield air defence, while the MiG-19s were tasked with all-weather interception of high-flying targets, namely, NATO nuclear bombers which would have to traverse both Bulgarian and Romanian airspace on their way to targets in the USSR.
The MiG-19 wasn't very liked in the BPAAF as it suffered from poor engine reliability. In fact, of the 58 total aircraft supplied, 28 were lost in crashes, killing 15 pilots, making an attrition rate of 48.2%, similar to the Lockheed F-104 Starfighter one, or, in another words, one accident per 1.000 flight hours. In fact, low serviceability and high attrition rate forced the 21.IAP to replace their MiG-19 with the MiG-17F/PF.
Some other sources claim, however, that only one pilot belonging to the 18.IAP/1.IAE was killed when he flew his aircraft into the ground due to de-orientation in clouds and that most non-fatal accidents with the MiG-19 were caused by poor maintenance.

Sources:

1. https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-19#Variants

2. Midland Publishing - Mikoyan-Gurevich MiG-19. The Soviet Union's First Production Supersonic Fighter

3. Salamander Books - The Complete Book of Fighters

Mikoyan-Gurevich MiG-17F, part six, various European users

The MiG-17F was the main fighter of many Warsaw Pact Users, among them, the following ones:

• Bulgaria: During the mid-to-late 1950s, the People's Republic of Bulgaria was supplied with batches of the newest Soviet jet fighters. The MiG-17F was active in the Bulgarian People's Army Air Force through the 1960s until the 1970s when it was withdrawn following a modernization period of the Bulgarian Air Force.
• Czechoslovakia: Some few MiG-17F served with the Czechoslovak Air Force before being locally produced as the Aero S-104. One of them was the personal aircraft of Gen. Jozef Kúkel who was the commander in chief of the 10th Air Army. Further details are unknown.
• East Germany: In 1956 the Soviet Union provided the newly established East German Air Force with many jet fighters and bombers, among them the MiG-17F. It served as their main interceptor/fighter until 1962 when the MiG-21 was introduced. After that, some of them were modified with added pylons to attach either bombs or rocket launchers. These modified machines were commonly known as the East German fighter-bomber and, while some of them were kept in active until the late 1980s, most of them were sold to African countries like Mozambique.

Sources:

1. https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-17

2. https://en.wikipedia.org/wiki/Bulgarian_Air_Force

3. https://en.wikipedia.org/wiki/Czechoslovak_Air_Force

4. https://en.wikipedia.org/wiki/Air_Forces_of_the_National_People%27s_Army

5. Salamander Books - The Complete Book of Fighters

Mikoyan-Gurevich MiG-15UTI, part eleven, Other European users

The MiG-15UTI served all across the globe, and it was also used by the following countries:

• Armenia: When the country was declared independent in 1991, some UTIs were left behind. They were incorporated into the newly created air force and were used in the Nagorno-Karabah war in the light-bomber role in 1992. All of them were presumably lost in that war. As we couldn't find graphical evidence of the type serving with the Armenian Air Force, the drawing should be considered as speculative.
• Bulgaria: The MiG-15UTI became the main trainer aircraft for the Bulgarian People's Army Air Force in the early 1950s when they were bought from the USSR. They served alongside other types like the Aero L-29 or the Aero L-39 until the fall of Communism in 1989 and even beyond as the type was still in active service in 1992. However, it was retired shortly after and replaced by the L-39 and the Pilatus PC-9. 
• Chechen Republic of Ichkeria: The Chechen National Guard Aviation had at least one MiG-15UTI that received the Chechen roundel. However it was destroyed on the ground during the first hours of the Chechen War in 1994. 
• Finland: In 1954 the MiG-15 was offered to Finland by the USSR, but the Finnish Air Force wasn't interested in the type, however, some years later, in 1962, as they needed an intermediate trainer before completing the transition to the MiG-21F-13, four MiG-15UTIs were ordered. In spite the UTI's good flying characteristics, the UTI didn't handle very well on ground and, as it didn't meet the demands of the Finnish Air Force, it wasn't used very much. It served until 7th February 1977 when it's last flight with the Finnish Colours took place.
• Romania: The Air Force of the People's Republic of Romania imported a total of 60 both Aero CS-102 (the Czechoslovak license-built MiG-15UTI) and MiG-15UTIs from 1953 until 1960. Given to the UTIs good flying characteristics and robustness, they were in service until 1992 making it, with more than 40 years, one of the most longeve aircraft to ever serve in the Romanian Air Force.

Sources:

1. https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-15

2. https://en.wikipedia.org/wiki/Armenian_Air_Force

3. https://en.wikipedia.org/wiki/Bulgarian_Air_Force

4. https://en.wikipedia.org/wiki/Chechen_National_Guard

5. https://en.wikipedia.org/wiki/First_Chechen_War

6. https://www.ilmailumuseot.fi/tuotteet.html?id=20171/255089

7. http://www.aripi-argintii.ro/aparatdezbor.php?p=24 (translated) 

Mikoyan-Gurevich MiG-15bis, Prototypes and rare versions

In this post we're covering many sub-variants, prototypes and dedicated versions of the Mikoyan-Gurevich MiG-15bis (excluding the MiG-15UTI which will have its series of own posts.
The MiG-15Pbis was a variant with just six exemplars built that featured a Torij radar mounted in a radome placed in the nose. It was armed with just the 37mm N-37 cannon to fit the radar equipment, just six of them were built with the first one being completed and flown on 23rd April 1949. It was built by the Moscow Aircraft Factory Number 155, in Moscow from converting a regular MiG-15bis. The remaining 5 were built by Kuybyshev Aircraft Factory Number 1 "Stalin", located at the Russian city of Kuybyshev in 1951. All six of them were used to train pilots in the usage of aircraft-mounted aerial-radars.
The MiG-15Rbis was a reconnaissance variant of the regular MiG-15bis. Three-hundred and sixty-four of them were manufactured by the Gorky Aircraft Factory Number 21, at Gorky, in Russia from 1951 to 1952. To incorporate the reconnaissance gear which consisted on a single AFA-BA/40 daytime camera, one gun was removed so it was armed with just the N-37 cannon and a single N-23 23mm cannon. It had a range of 1045km (649,33 milles) without external fuel tanks and it's worth mentioning that it differed from the Czechoslovakian version as this one was based on the MiG-15bis and the Czechoslovakian version was based on the regular MiG-15. It served with the VVS (Soviet Air Force), the Bulgarian People's Air Force (which, as we couldn't find a pic, the drawing should be considered as speculative) and the Cuban Air Force (which we also couldn't find a pic, so the drawing should be considered as speculative) performing low-level recon missions.
The MiG-15Sbis was a variant with integrated fuel tanks added into the wings in order to achieve a greater range. It had a range of 1200km (745.64 milles), it was produced in 1951 by the Saratov Aircraft Factory Number 22 in Saratov, Russia, which produced all 45 of them. It was armed like a regular MiG-15bis and only saw brief service with the VVS.
The MiG-15bis(ISh) was a ground-support variant. Only 4 of them were manufactured plus other 12 which were converted from the MiG-15bis. All of them were produced or converted by the Research Institute of Air Force for Aircraft Operations and Repairs in 1958. As it was intended for ground-support duties, it had an additional underwing hardpoint to carry a wide arrangement of bombs and/or air-to-ground rockets, apart of the traditional N-37 and NR-23 guns.
The MiG-15bisR was a recon variant locally produced in Czechoslovakia at the town of Kbely by Letecké opravny Kbely n.p.. Seventy-six of them were converted from regular MiG-15bis (or its Czechoslovak licensed version built by Aero) during a production period starting in 1960 until 1963.
As in its Russian counterpart, in order to fit the photographical equipment, it was underarmed with just one NR-23 gun.
Lastly, we have the MiG-15bisSB which was a ground-attack version also built and converted by Letecké opravny Kbely n.p. from either regular MiG-15bis or MiG-15bisR aircraft. Production started as late as 1968 and lasted until 1978 having manufactured 72 machines plus an unknown number of conversions. It featured hardpoints to carry a set of ground-attack rockets (most notably the LR-130 and the LR-55 rocket launcher) and up to six OFAB-100 bombs.
Most of them served with the Czechoslovak Air Force during the 1960s and the 1970s and, apparently, some of them were exported to Iraq where they served in the Iraqi Air Force, however, as we couldn't find any photo or pic whatsoever of the MiG-15bisSB under Iraqi colours, the pic should be taken as speculative.

Sources.
1. https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-15
2. https://forum.valka.cz/topic/view/196279
3. https://forum.valka.cz/topic/view/196286
4. https://forum.valka.cz/topic/view/60332
5. https://forum.valka.cz/topic/view/196285
6. https://forum.valka.cz/topic/view/53557
7. https://forum.valka.cz/topic/view/60333
8. https://forum.valka.cz/topic/view/196279

Mikoyan-Gurevich MiG-15bis, various European users

The Mikoyan-Gurevich MiG-15bis, which basically was an improved variant of the MiG-15, was introduced in 1950 and soon equipped the fighter force of many eastern bloc/Warsaw pact countries. Among those countries, there are the following:

• Bulgaria: After the end of the Korean war, where the MiG-15bis showed its capabilities, in 1955 the old propeller-driven Soviet-build fighters were replaced by MiG-15 and MiG-15bis entering the Bulgarian Air Force in the jet age, even if they had been already operating a very small number of Yakovlev Yak-17 fighters. They were gradually replaced by the MiG-17 during the next years.
• German Democratic Republic: When the Air Forces of the National People's Army was formed in 1956, they were initially equipped with the MiG-15bis which were replaced soon after with the introduction of the MiG-17F/PF and the MiG-15bis was soon relegated to advanced trainer duties.
• Hungarian People's Republic: Like other neighbouring countries of the eastern bloc or Warsaw Pact, until mid-1950s their Air Forces were equipped with World War II Soviet propeller aircrafts even if they received a small amount of Yakovlev Yak-23 as interim fighters. As that material had to be modernized, they received both MiG-15 and MiG-15bis which replaced every previous fighter type and were replaced by the more advanced MiG-17
• Socialist Republic of Romania: The Air Force of the Socialist Republic of Romania received their first jet aircrafts in 1951. They were an amount of Yakovlev Yak-17UTI trainers which were used to train pilots into the usage of jet aircraft. Soon after, in 1954, the Romanian Air Force received both the MiG-15 and MiG-15bis which replaced the old propeller-driven outdated fighters, which, in Romania, some of them were still Messerschmitt Bf.109G-6.

Sources:

1. https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-15

2. https://en.wikipedia.org/wiki/Bulgarian_Air_Force

3. https://en.wikipedia.org/wiki/Air_Forces_of_the_National_People%27s_Army

4. https://en.wikipedia.org/wiki/Hungarian_Air_Force

5. https://en.wikipedia.org/wiki/Romanian_Air_Force

Mikoyan-Gurevich MiG-15, Various European users

The Mikoyan-Gurevich MiG-15 was used by every European member of the Warsaw Pact. As both Poland and Czechoslovakia manufactured them separatedly, we will cover them in other post.

• Albania: Back when the Albanian Air Force was created in April 1951, they received some outdated Yakovlev Yak-9 and, on 15th May 1955, they received second-hand MiG-15 that had been used in the Korean War. They were replaced by the Mikoyan-Gurevich MiG-17.
• Bulgaria: When the Bulgarian People's Army Air Force was re-established just after the World War two, they were equipped with propeller driven Soviet aircrafts like the Ilyushin Il-2, Ilysuhin Il-10 or the Tupolev Tu-2. In 1954 they were withdrawn as, since 1951 they had been receiving jet aircrafts like the MiG-15 which remained in service until they were replaced by the MiG-17.
• East-Germany: In the beginning of 1953, one MiG-15 was delivered to the East-German KVP-Luft (Kasernierten Volkspolizei - Air Garrisoned Police) which was the predecessor of the East Germany Air Force. They flew under Soviet colours, but, shortly after, on 17th June, they were taken back by Soviet authorities.
• Hungary: Just like every surrounding countries, the MiG-15 was the first jet fighter to operate with the newly created Hungarian People's Air Force during the early 1950s. They were replaced by the MiG-17 during late 1950s. As we couldn't find graphical evidence of the regular MiG-15 in Hungarian colours, the drawing should be considered as speculative.
• Romania: The Air Force of the People's Republic of Romania received MiG-15 in 1952 which served alongside the MiG-15bis and the MiG-17 until 1958, when they were replaced. The drawing should be considered as speculative as graphical evidence of the regular MiG-15 under Romanian colours seems to be nearly impossible.
• USSR: The MiG-15 was the backbone of the Soviet Air Force. It was in service since its introduction in 1949 and served alongside the improved MiG-15bis with the main Soviet Air Force units. It was produced from 1949 until 1953 in various Soviet factories and a total number of 1344 exemplars were manufactured in Soviet soil only at factories in Saratov, Moscow, Novosibirsk, Komsomoslk-on-Amur and Kuybyshev. Most of them were gradually replaced by the MiG-17 when it was introduced in 1952.

Sources:

1. https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-15

2. https://en.wikipedia.org/wiki/Albanian_Air_Force

3. https://en.wikipedia.org/wiki/Bulgarian_Air_Force

4. https://en.wikipedia.org/wiki/Air_Forces_of_the_National_People%27s_Army

5. https://en.wikipedia.org/wiki/Hungarian_Air_Force

6. https://en.wikipedia.org/wiki/Romanian_Air_Force

7. https://forum.valka.cz/topic/view/53179

8. Salamander Books - The Complete Book of Fighters