Lazarov Laz-14

 

During the 1950s it was clear that piston-engined aircraft were a thing of the past and the jet engine was the future.

At that decade, the Bulgarian aviation industry was already been cut off and made dependant of the Soviet. Most of Bulgarian aeronautical industry was reconverted to manufacture cars, electric pumps or even bee hives.

However, in Sofia, at the State Polytechnic there was still an faculty of Aeronautical Engineering and the people working there didn't want their work, carried over for more than 30 years, to fall into oblivion so ingloriously. They think that the dismantling of the Bulgarian aeronautical industry was a gross mistake and that the government should reactivate it.

Among that people was prof. Tsvetan Lazarov, dean of the faculty of Aeronautical Engineering. The father of designs like the DAR-6, DAR-6A, DAR-9, DAR-10 , Laz-7 , Laz-7M and Laz-12 thought about the future of the Bulgarian aeronautical industry and tried to revive it in the following years. So, in order to keep pace with the technological advances of the world aeronautical industry, specially regarding trainer aircraft, he started a project for a jet-powered trainer that could be used both by air forces and even flying clubs.

The copies of the designs that survived the Cold War, labelled as Laz-14, are dated 26th June 1958, meaning that work on the project began much earlier. 

Initial sketches were clearly inspired by the Czechoslovak Aero L-29 which was designed by Karel Tomasz and Zdenek Rublich, both colleagues of Lazarov. However, unlike the L-29 which flew for the first time in 1959 and was one of the main jet trainer aircraft of the Warsaw Pact and other countries, the Laz-14 couldn't pass the design stage. 

Laz-14 was designed as a two-seater, single-engined jet trainer for primary training and pilot training support. As it was expected to be armed too, it could've also performed some sort of ground support missions.

It was going to be made entirely out of metal, with trapezoidal-shaped low-wings with two spars and a strongly developed central section. Air intakes were to be located at the roots of the wings. It was also equipped with a tricycle retractable landing gear which retracted into the fuselage. The wings were to be equipped with ailerons with axial compensations and flaps for take-off and landing. They had spindle-shaped fairings at both ends to reduce inductive drag.

The power section of the fuselage was a steel pipe truss. It was going to be equipped with a fully-glazed cockpit with two seat arranged in a tandem configuration, with the student  sitting at the front and the instructor at the rear.

Lazarov wanted the Laz-14 to be powered by the French Turbomeca Marboré engine which could yield a thrust power of 400-480 kgf and was already powering some successful trainer aircraft like the Fouga Magister or the Morane-Saulnier Ms.760 Paris. However, considering the political situation of the time, it was more likely to be powered by the Czechoslovak Motorlet M-701, which powered the aforementioned Aero L-29. Anyway, the engine was going to be placed in the centre of the fuselage to avoid the loss of thrust power in the extension tube.

Tail planes' design were traditional. Elevator and rudders had aerodynamic compensation and trim tabs were going to be controlled from the cockpit. The horizontal stabilizer was going to have the ability of deviating 3 degrees up or down to facilitate aerobatics with either one or two pilots.

According to calculations, the Laz-14 was going to be extremely light, 700 kg (1.543 lbs) empty (for comparison, the mass of an empty L-29 is 2.280 kg - 5.026 lbs). Apparently, considering the expected numbers there is little doubt that, if the aircraft had been made, it would've been successful among Bulgarian pilots, as it would've fully met the requirements of the time.

Source:

http://www.airwar.ru/enc/other/laz14.html (translated and adapted)

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-9

 

Professor Tsvetan Lazarov, one of the best aircraft designers of Bulgaria, lived through difficult times. The new world order that came after World War 2 was setting up across the world and there was a war going on in the Korean Peninsula. At the same time, the Bulgarian Air Force was heavily cut and purged politically after the war, leaving it short on flight and technical staff. This situation required a large number of pilots, navigators and aircraft technicians to be trained in a short period of time. As pilots and navigators must receive comprehensive and solid combat training, the Lazarov Laz-7 was employed, much to Lazarov's dismay, as a multi-purpose heavier-than-intended aircraft that went from the initial 947 kg (2088 lbs) of the prototype to the 1145 kg (2524 lbs) of the production version, worsening flight characteristics. 

In order to express his concerns about the usage of the aircraft, Prof. Lazarov wrote a letter to the Bulgarian Air Force Command, Metalchem Industrial Association (manufacturers of the Laz-7) and other institutions involved in the manufacturing process of the Laz-7. In this letter, dated at 10th October 1950 he stated that it was unacceptable the further degradation of the flight characteristics of the Laz-7 and suggested to keep the Laz-7 for the initial basic pilot training and have a new aircraft type (namely Lazarov Laz-9) as the multi-purpose airplane to assume those roles not intended for the Laz-7. For this purpose he described the design of the Laz-9 further in the letter.

The Laz-9 was designed around the German Argus As.410 engine, which yielded up to 450 hp of power, due to the fact that many of them were left over in Bulgaria, some of them even unused. The Laz-9 was going to feature a larger, strengthened and expanded fuselage reminiscent of the Laz-7 with a metallic tail unit and trapezoidal wing with TsAGI (Moscow's Central Aerohydrodynamic Institute) designed flaps. Undercarriage was designed as retractable, similar to that of the Yakovlev Yak-9.

Thanks to the more powerful powerplant, the Laz-9 was expected to take additional equipment and even carrying heavier weapons, allowing the optimal performance of additional combat tasks. It was intended to be armed with a single 13 mm (0.5 in) machine gun mounted on the engine, plus two additional 7,92 mm (0,3 in) lighter machine guns placed in the wings. It was designed to carry a payload of up to 400 kg (882 lbs) of underwing bombs, in, either 8 x 50 kg or 4 x 100 kg configuration. 

Apparently Lazarov's letter was ignored, as the Bulgarian Communist regime had already decided to dismantle the Bulgarian aviation industry, following orders from Moscow and the project never went beyond the design stage. 

Sources:

http://www.airwar.ru/enc/other/laz9.html (translated and adapted)

Breguet 14. French Users. Part six.

 

After the Great War, the Breguet 14 was kept in active service until mid 1920s, the type being employed in various French colonial campaigns, such as Syria, Morocco or even Indochina.

An ad-hoc variant, called Breguet 14 AE and registered as F-AEEZ was designed specifically to be used in the French colonies. It flew for the first time in 1920. 

The Aéronautique Navale (French Naval Air Arm created back in 1912) had around 100 Breguet 14 in service in the year 1922. The reconnaissance units assigned to the Aviation d'Escadre were equipped with the Breguet 14A.2, while other Breguet 14s were assigned to training units at Saint-Cyr, Rochefort, Hourtin and Sidi-Ahmed. Although they were not assigned to the Béarn (France's first aircraft carrier), they served as trainers for the carrier-designed Levasseur PL.4 recon-bomber that served aboard the Béarn. 

During the early 1920s the Breguet 14 was gradually being replaced by more modern types in metropolitan France. Some units replaced the type with the Potez 15, but most of them received the Breguet 19. 

By 1926 there were still 376 Breguet 14A.2, 340 B.2s and 95 Tbis Ambulance still in service with the Aéronautique Militaire based in mainland France. By the late 1920s, however, they were already replaced by either Breguet 19, Potez 15 or Potez 25.

The Breguet 14 saw also service in Morocco. Apparently the whole 37e Régiment Aérienne Observation  (RAO - Aerial Observation Regiment), composed by ten escadrilles, employed Breguet 14A.2s, B.2s and Tbis when deployed in the Moroccan region. Four escadrilles of the 37e RAO took part in the conquest of Ouezzane, in the context of the Rif War. During 1922 and 1923 all units of the 37e RAO were used in operations around the Moyen-Atlas border, with two ambulance escadrilles, equipped with both with Br.14Ss and Br.14Tbis evacuated up to 870 stretcher cases.

Escadrille 7, 8 and 10 saw action in 1924 to help deal with uprisings in Northern Morocco in support of French troops, outposts and forts in the context of the Rif War.

One of the escadrilles that took part in this campaign was the so called escadrille Chériffienne, which was an unit composed by American volunteers. This unit helped the Aéronautique Militaire in their war against the Rifian rebels and was attached to the Moroccan Royal Guard or Garde Chérifienne (hence the nickname and the symbol - the Moroccan Star - of the unit).
The escadrille Chérifienne was activated on 7th August 1925 and operated seven Breguet 14B.2 bombers and was assisted by a ground crew of 59 French men. They were based at the town of Beni Malek (Northern Morocco) and the unit took part in the bombardment of city of Chefchaouen on 17th September 1925 to drive Jebala people out of the war as the city was considered holy by that tribe. This unit was part of the French occupation forces in Morocco on 15th October 1925 and was disbanded on 15th November 1925.
By mid 1925 the insurrection in the northern region was stopped but it was revived later that same year. Again eight bombing/observation escadrilles plus two ambulance ones were deployed in action, all them equipped with the Breguet 14. Four additional Breguet 14 escadrilles were also deployed in the Southern Front which were complemented with six Breguet 14 autonomous escadrilles brought from Algeria and Tunisia, two escadrilles from the 11e RAO in France. Two units, escadrilles 5 and 6, were transferred from the south to the north to serve as temporal replacements. 

In September 1925 two Br.14A.2 from the 32e RAO, based in Algeria, were also sent to Morocco. The units based in northern Morocco flew a total of 5.500 sorties from July 1925 to January 1926. During the spring 1926 the 37e RAO continued to support the occupying ground troops in the Rif. The Battle of Taza pocket saw intense action of the Br.14B.2s as a total of 12 tons of bombs were dropped allowing the French troops to retake the city. 

When the Moroccan campaign ended in June 1927 the 37e RAO was composed by ten escadrilles: 1e, based at Beni-Malek, 2e, based at Taza, 3e, based at Bou-Denib, 4e, based at Beni-Malek, 5e, based at Marrakech, 6e, based at Kasbah-Tadla, 7e and 8e, both based at Meknes, 9e, based at Assaka and 10e based at Fez. 

Most of those escadrilles were equipped with either the Br.14A.2, Br.14B.2, Br.14S or the Br.14Tbis. However, by the next year they were replaced by Breguet 19A.2s Br.19B.2s or the Breguet 26T (the transport variant of the Br.19).

 

Sources:

1st https://en.wikipedia.org/wiki/Bréguet_14

2nd Flying Machines Press  - French Aircraft of the First World War

3rd https://en.wikipedia.org/wiki/Escadrille_Cherifienne

4th https://en.wikipedia.org/wiki/Bombardment_of_Chefchaouen

Breguet 14. French Users. Part six.

 

The Breguet 14H was a floatplane variant of the Br.14 powered by a single Renault 12Fe engine yielding 320 hp of power. It was equipped with a large central float beneath the central fuselage plus two smaller floats under the lower wings. Two machines were made and served with the Aéronautique d'Indochine. As the profile is based in an old photo, the colours should be considered as speculative.

The Breguet 14T and 14Tbis were civilian variants of the Br.14. The 14T was a conversion of the basic Br.14 modified to carry two passengers in a cabin in front of the pilot's cockpit. Entrance door was on the starboard side. A development of this variant was the Br.18T which was an enlarged version of the 14T equipped with a 450 hp Renault 11Ja engine. In its enlarged cabin there was room for four passengers.

The Br.14Tbis was a hybrid variant of both the Br.14T and the Br.18T. It had a cabin for three passengers and was, by far the most widely used transport variant. 

After the war, both Br.14As and Br.14Bs were kept in France until the mid-1920s, being key part of the French occupation force in the Rhineland and would be also employed later in the Rif War. A total of 40 escadrilles were disbanded in 1919, with a major reorganization being made in 1920. 

The Br.14A, B and T variants and sub-variants saw widespread usage in the post-war French colonial campaigns. After the partitioning of the Ottoman Empire, France was granted the mandate of Syrian and Lebanon, where the French forces deployed there were tasked with fighting the various rebellious desert tribes. For this task two escadrilles were assigned, Escadrille 52 (ex BR 117) based at Rayak (Lebanon) and Escadrille 53 (ex BR 120) all of them under the command of General Lamothe. In this campaign the Br.14s were used in the reconnaissance, light bombing (carrying usually 12 ten kg (22 lbs) bombs) and ambulance roles. 

When the Great Syrian Revolt of 1925 took place all the escadrilles present in Syria, among them the two equipped with Br.14s, were employed against the rebels. They flew a total of 6.000 patrol sorties, 4.000 bombing runs. The Br.14s played a decisive part in the relief of the city of Jabal Djebel Druse where 7.000 French soldiers were besieged. From 26th July to 24th September 1925 the Aéronautique Militaire flew over 200 sorties dropping 12 tons of food and 54 sacks of mail over the besieged city in what is considered to be one of the first airlifts in history. 

Sources:

1st https://en.wikipedia.org/wiki/Bréguet_14

2nd Flying Machines Press  - French Aircraft of the First World War

Breguet 14. French Users. Part five.

 

The Breguet 14 saw some sub-variants, like the Br.14 Ap.2 which was done for a 1917 specification calling for a high-altitude long-range reconnaissance aircraft. A single machine was fitted with an American made Liberty 12 engine rated at 400 hp. It was tested at Villacoublay, Seine-et-Oise department, and neither this, nor its competitor, the Hanriot Dupont 9, were selected by the Aéronautique Militaire. 
A similar arrangement was tested at McCook field, Ohio, on a Breguet Br.14B.2. Tests determined that the Liberty engine neither improved nor harm Br.14's performance, so it was considered as a valid alternative to Renault or Fiat engines, should the war continued beyond 1918. On the Br.14A.2 variant, however, the Liberty engine improved performance considerably over the Renault engine.

The Breguet 14A.2 was also tested with the Lorraine-Dietrich engine, as a single machine was fitted with a 285 hp Lorraine-Dietrich 8Bd. It was considered successful enough to warrant production, with some sub-versions having blunt cowling and underslung radiator.

The French bombing groups saw less activity during the month prior to the Battle of the Aisne. It was during this period that two principal innovations were introduced: Fighter groups began to develop effective escort tactics to help bomber reach their targets and diversionary raids were also introduced to draw German fighters away from the targets. Groupes de Bombardement (GB) 5, 6 and 9 moved to Foulloy, Somme department, where they were assigned to support 1re and 3e Armée. GB 3 was based at Fourneuil, in the Oise department and GB 4 at Villenueve-le-Roi, close to Paris. Between 16th and 27th May 1918 many fighter groups were assigned to escort the bombers. Although most of the raids performed using those tactics were successful, the Commander of the Aéronautique Militaire complained that the size of such big aerial armadas made them unwieldy. As we said, during this period diversionary raids were also introduced, and such attacks were made employing a small number of bombers against objectives well away from the primary targets. This drawn attention (and German fighters) away and were periodically repeated throughout the remainder of the war.

In the Battle of the Aisne, from 27th May to 4th June, the GBs concentrated their attacks on German supply lines and communications in an attempt to slow them down. However, the units had to be rebased various times because the quick-changing situation of the frontlines endangered many of the French airfields. The activity on the eastern part of this front increased in early June, where GBs 3, 4, 5, 6 and 9 bombed troop concentrations in the Ourcq valley.

During the Battles of Metz and Soissonais, which took place between 5th June to approximately 15th July, GBs 5, 6 and 9 supported ground troops, together with the Royal Air Force's 9th Brigade, and took part in the defence of those towns. 

During the next major engagement, the Battle of Champagne in late July, a new tactical innovation was introduced. The Br.14B.2s were escorted for the whole duration of their missions, by the Caudron R.11 escort fighters, which had both range and firepower to escort them, and were most of the time accompanied by the SPAD S.XIII fighter. The GBs were now fighting on the offensive, bombing retreating German troops. These kind of attacks took place during the following months at the Battles of Île de France, Santerre and St. Mihiel, where the GBs supported the American 1st Army. Thanks to those large formations, the bombers could attack German targets with relative easiness being the Luftstreitkräfte all but defeated. 

During the last year of the war, Breguet 14B.2s helped French and American armies to hold the initial German attacks first and to disrupt the German lines later, when counter-offensives began, making an important contribution to the final Allied victory in World War I.

In the recon and artillery cooperation role, some of the escadrilles that employed the A.2 during wartime were:

• BR 35: This escadrille, created from AR 35, replaced their Dorand AR.2 with Breguet 14A.2 in November 1917. It was attached to the 35e Corps d'Armée and was active in the 1re Armée sector. During the Battle of Picardie, it was based in many locations like La Ferté-sus-Jouarre (Seine-et-Marne department), Les Andelys (Eure department) and Fienvillers (Somme department). In May 1918 it took part in the Battle of Chemin-des-Dames and moved to Le Tergnier (Aisne department) afterwards. After the war it became the 5e Escadrille of the 2e Régiment Aérien d'Observation (RAO - Aerial Observation Regiment) in January 1920.
• BR 234: This unit, originally called SOP 234, transitioned from the Sopwith Strutter to the Br.14A.2 in May 1918. It was assigned to the 1re Armée and was based at Libermont, Oise department, when the war ended. After the war, when the Aéronautique Militaire was reorganized, it became the 2e Escadrille of the 1re Régiment Aérien d'Observation (RAO - Aerial Observation Regiment) in January 1920.
• BR 281: This escadrille was formed from SOP 281, which replaced their Sopwith Strutters with Breguet 14A.2s. It was assigned to the 17e Corps d'Armée (17th Army Corps) which operated in the American 1st Army Sector. The escadrille was based at Beauzée, Meuse department and was disbanded in April 1919. 

Sources:

1st https://en.wikipedia.org/wiki/Bréguet_14

2nd Flying Machines Press  - French Aircraft of the First World War

Breguet 14. French Users. Part four.

 

The Breguet 14S was an ambulance variant of the regular Br.14. The Frenchs pioneered the ambulance aircraft technology. It was originally made to supplement the ambulance version of the  ageing Voisin X, aircraft which was eventually replaced by the Br.14S. These Br.14 were designated as Br.14S (the letter "S" standing for Sanitaire). The initial versions were regular unarmed A.2s modified to just carry two stretcher cases in the rear fuselage, however, afterwards a dedicated ambulance version was produced using a modified version of the Br.14T transport variant. The first recorded usage of a Br.14S was in 1918 over the Aisne front, when four Br.14S were employed to evacuated wounded officers from the frontlines.
After the war, they were also employed in the French colonial campaigns of Morocco, Syria and Algeria and some of them were employed in the Rif War.

Back to the bomber variant, during 1918, the Br.14B.2 equipped every day bomber group of the Aéronautique Militaire (AM - French Military Aviation), namely, Groupes de Bombardement (GB) 3,4,5,6 and 9. Between January and March 1918 those units were active all along the frontlines. Groupe de Bombardement 3 was attached to the 3e Armée and was specialized in high altitude (above 5.000 m - 16.4042 ft) bombing and GB 4 attacked targets inside Germany, with attacks on Pechlebon, Rothwreil, Karlsruhe and Stuttgart. 
GB 5 was employed on a mixture of reconnaissance and attack missions over Châlons-en-Champagne, in the Marne department, GB 6 attacked railway stations all along the front and GB 9 was formed on 11th March 1918, just before the Battle of Picardie and was assigned to Escadre 12. 
During the Battle of Picardie and Flanders which took place from 21st March 1918 until 19th April 1918, all of the five Br.14-equipped escadrilles took part. GB 3, based at Maisonneuve, while the rest of the GBs were based at Villenueve-le-Roi, close to Paris. 
On 23rd March Breguet units began their attacks, with special attention being paid to attacks on troop convoys, train stations and German troops on the frontline. Normally, those targets were attacked with bombs, but the Battle of Picardie saw the first time widespread strafing of frontline troops. Additionally the Br.14s dropped modified 75 mm shells modified as anti-personnel weapons. The combined efforts of every GB was required in order to sustain the aerial offensive on this sector of the front. Other typical targets for the Br.14B.2 were troop concentrations on the rear guard, bridges and supply lines that could slow the German advance. By late March GB 5, 6 and 9 were rebased to Plessis-Belleville, in the Oise department and GBs 3 and 4 were rebased to Cramaille, in the Aisne department. During the first week of April, the front had stabilized enough, so the GBs could concentrate on resuming their typical attacks on railroads and airfields. 
Thanks to the raids on German airfields, which destroyed a significant amount of enemy aircraft, the French bombers encountered significantly less aerial opposition. This disruption caused on the Lüftstreitkrafte (Imperial German Air Corps) allowed the Br.14s to concentrate their attacks on command centers and supply dumps far behind enemy lines. 
As the Battle of Picardie kept on, an innovative tactic took also place. Various SPAD fighters were assigned to escort the bombers. However, many times the planned rendezvous between bombers and fighters didn't take place, so the Br.14B.2s often had to proceed unescorted. On 3rd April GB 3 and 4 were rebased to Beauvais, in the Oise department and GBs 5, 6 and 9 were moved on to Montagne. During this battle the Breguet escadrilles helped to slow down the German onslaught on Picardie and Flanders giving the Allied forces a time to recover.

In the reconnaissance role, there were also various Escadrilles that employed the Br.14A.2, some of those were:

• BR 227: This unit was created in October 1917 from C 227. It was under the command of Capitaine Poucher and was active in the 4e Armée's sector. It ended the war based at Rumont, Seine-et-Marne department, attached to the American 2nd Army. After the war, in January 1920, it became the 7e Escadrille of 4e Régiment Aérien d'Observation.
• BR 287: Formed from SOP 287 in June 1918. This unit was attached to the 52e division d'infanterie (52nd Infantry Division), and was based at Roucy, in the Aisne department, in the 5e Armée sector. It was disbanded shortly after the war, in December 1918.

Finally, some A.2 were also field-modified with the addition of photo cameras installed on the sides of the fuselage in the observer's cockpit.

Sources:

1st https://en.wikipedia.org/wiki/Bréguet_14

2nd Flying Machines Press  - French Aircraft of the First World War