Bulgarian Aviation in World War II

In August 1940, Bulgaria presented territorial claims to Romania, demanding the return of the southern part of the Dobruja plateau, lost as a result of the defeat in the Second Balkan War in 1913. At the suggestion of Germany and Italy, the issue of territorial claims by Bulgaria and Hungary against Romania was submitted to a special International Arbitration Court in Vienna. As a result of this court’s decision, Bulgaria received the demanded territories back on September 7, 1940.

In the autumn of 1940, Hitler decided to attack Greece, which was already at war with Italy. England sent its troops to aid Greece, and British bombers, based at Greek airfields, could, if necessary, strike the Ploiești oilfields in Romania from there, which were one of the main fuel sources for the Third Reich’s war machine. However, Greece was too far from Germany’s borders, and therefore it was first necessary to secure the support of a number of Eastern European states that would allow German troops to pass through their territory.

In November 1940, unable to withstand intense German pressure, Hungary, Slovakia, and Romania joined the tripartite military-political pact “Rome-Berlin-Tokyo.” Only Bulgarian Tsar Boris III was still deliberating whether to do the same. Despite Bulgaria’s still unclear position, Hitler issued an order on December 13, 1940, to develop a plan for the invasion of Greece, codenamed Operation “Marita.”

Its plan stipulated that the 12th Field Army, supported by the 8th Air Corps, should begin an offensive against Greece from Bulgarian territory. In the winter of 1940-41, a special group of Luftwaffe advisors was sent to Bulgaria, whose main task was to organize the preparation of Bulgarian airfields for receiving German aircraft. Simultaneously, the construction of a network of new airfields began in Bulgaria, the total number of which was to reach fifty. Meanwhile, Wehrmacht units, which began concentrating on the Romanian-Bulgarian border, became a very serious argument for Tsar Boris III, and on March 1, 1941, Bulgarian representatives signed documents in Vienna to join the “Rome-Berlin-Tokyo” pact.

Despite Bulgaria becoming an ally of the Third Reich and providing its territory for the deployment of German troops and aviation, it did not itself participate in the invasion of Greece and Yugoslavia, which began on the morning of April 6, 1941. Although Yugoslav and British aircraft carried out several raids on Bulgarian border towns, causing strong panic among the local population, Bulgaria did not take any retaliatory steps, and its army remained in place.

After Wehrmacht units occupied Greece and Yugoslavia, Bulgaria received back its former territories in Macedonia and Northern Greece as a “thank you” for assisting the Third Reich. Additionally, the Luftwaffe then transferred eleven captured Yugoslav Do-17Kb-l bombers to Bulgarian aviation, which had been manufactured under German license at the Kraljevo aircraft factory, 122 km south of Belgrade.

In total, from September 1940 to April 1941, Bulgaria, without participating in combat operations, increased its territory by 50% and its population by a third. A “Greater Bulgaria” once again emerged, stretching from the Black Sea to the Aegean Sea.

Bulgaria’s Early Involvement and Anti-Submarine Operations (1940-1942)

Despite Bulgaria maintaining an extremely cautious stance, in 1941, it ultimately could not avoid participation in combat operations. The day before the attack on the Soviet Union, the military attaché at the German embassy in Sofia appealed to the Bulgarian air force headquarters with a request to deploy Bulgarian aircraft to protect German sea communications in the Aegean Sea. As a result, by order of the chief of staff of the Bulgarian air force, a special mixed group was created based on aircraft and crews from the 5th Bomber Regiment, consisting of a staff and two squadrons, equipped with nine Do-17s and six Avia B-71s.

On June 23, Bulgarian bombers were relocated to the former Greek airfield of Kavala on the Aegean Sea coast, where the 443rd Bulgarian Reconnaissance Squadron had been stationed since May 5. Together with crews of German reconnaissance seaplanes, Bulgarian pilots searched for British submarines along the routes of German convoys north of Crete. It should be noted that at that time Bulgaria was not yet at war with England (it declared war on England and the USA only on December 13, 1941). In total, from June 23, 1941, to January 3, 1942, Bulgarian bombers conducted 304 patrol flights over the Aegean Sea, but only in two of them did they have visual contact with enemy submarines.

Because sympathies for Russia, which had liberated them from centuries of Ottoman rule, were strong among Bulgarians, Germany never insisted on the participation of Bulgarian army units in combat operations on the Eastern Front. Despite being an ally of the Third Reich, Bulgaria nevertheless did not declare war on the Soviet Union, and diplomatic relations between the two countries, established in July 1934, continued. However, after the start of hostilities on the Eastern Front, Stalin, clearly displeased with Bulgaria’s position, ordered the initiation of a real submarine war against it.

By August 10, 1941, four combat positions for Black Sea Fleet submarines were located in Bulgarian territorial waters: No. 12 off Cape Kaliakra, No. 13 between Varna and Cape Emine, and No. 14 in the area of Tsarevo (now Michurin). On October 11, the number of combat positions for Soviet submarines off the Bulgarian coast was increased to five. Now, position No. 20 was north of Cape Kaliakra, position No. 21 in the Varna area, No. 22 in the Cape Emine area, No. 23 in the Burgas area, and No. 24 was located south of Burgas.

The peak of activity in this undeclared war occurred from July to October 1941. Black Sea Fleet submarines conducted reconnaissance, landed sabotage and reconnaissance groups, attacked ships, including those of neutral countries (especially Turkish ones), and laid minefields in Bulgarian waters. The Bulgarian transport “Shipka” hit one of these mines and sank. Additionally, on September 9, the submarine L-4 sank the Bulgarian schooner “Uspekh” with artillery fire.

On July 31, the German command was forced to involve Bulgarian aviation in providing anti-submarine defense for its sea convoys, which passed through Bulgarian territorial waters from Romanian ports to the Bosphorus Strait and back. Specifically for this task, on August 4, 1941, a “Composite Squadron” (сборно войсково ято) was formed, initially equipped with nine Letov S-328 aircraft. The first flight of five aircraft was based at Balchik airfield, 31 km northeast of Varna, and the four aircraft of the second flight were stationed at Sarafovo airfield, 10 km northeast of Burgas. In mid-October, the squadron received three more S-328s and was transformed into a “Composite Group” (сборен вой-скови орляк) with two squadrons of six aircraft each.

The group received specific combat assignments from a Kriegsmarine representative in Varna. Initially, Bulgarian pilots had two tasks: to search for Soviet submarines along the convoy routes and to warn ships of their appearance, and to attack submarines detected within Bulgarian territorial waters with bombs and machine-gun fire. Later, these tasks were supplemented with mine and minefield detection at the entrances to Varna and Burgas ports, covering Bulgarian ships during mine-laying operations, rescue operations, and aerial photography.

In the first months, one aircraft, armed only with machine guns, continuously patrolled over the guarded convoy, while several standby aircraft with two to six 20-kg bombs remained on the ground. Upon detecting the enemy, the patrol aircraft’s crew signaled the convoy and called for standby aircraft, simultaneously firing at the submarine with machine guns. The effectiveness of such tactics proved very low, and later S-328s began patrolling with bombs already attached. For safety, if bombs could not be used during a sortie, they were simply dropped into the sea before landing.

Five instances of combat contact between Bulgarian aircraft and Soviet submarines were documented in the summer-autumn of 1941. On August 16, at 13:45, a patrolling S-328, escorting the Bulgarian vessel “Tsar Ferdinand” and the Romanian “Cavarna,” detected a submarine between the mouth of the Kamchiya River and Cape Emine. The crew fired at it with a machine gun, and a called-in standby aircraft dropped four bombs. Then, three more S-328s arrived in the area, dropping eight bombs. However, no signs of damage to the submarine were found on the sea surface. It is assumed that the Shch-211 of Captain-Lieutenant Devyatko, which had landed an illegal group led by Tsvyatko Radoy-Nov near the Kamchiya estuary, was attacked. Probably, this same submarine then attempted to attack an air-guarded convoy off Cape Emine on August 30. The aircraft’s actions were identical to the first case, and the result was the same.

On September 21, an aerial patrol in the Shabla-Varna area detected a submarine attempting to attack a convoy of two Romanian transports and five Bulgarian escort ships. A standby S-328, as well as one German and one Romanian aircraft, were called to the area. However, by the time they reached the convoy, the submarine had already managed to escape.

On September 29, an S-328 crew escorted a convoy of three Italian tankers on the Varna-Burgas route. Bulgarian pilots did not notice the submarine that managed to torpedo the tanker “Superga.” The torpedoes hit the stern of the vessel, and it quickly sank. According to Soviet sources, this was the same Shch-211. (On November 16, 1941, it hit a mine off Cape Shabler and perished with its entire crew. In total, in 1941, the Black Sea Fleet lost 8 submarines, three of them in Bulgarian waters. On November 12, the S-34 hit a mine off Cape Emine, and on December 6, in the Varna area, Bulgarian patrol ships sank the Shch-204.)

On October 15, a single transport ship was sailing along the Varna-Shabla route, escorted by four Bulgarian warships and one S-328 patrol aircraft. At 10:55, a submarine moving towards the ships at periscope depth was detected from the aircraft. This time, the S-328 carried six 20-kg bombs, two of which were dropped during the first attack. Bulgarian pilots recorded a hit on the submarine’s hull, after which it quickly dived. The crew dropped the remaining bombs, but the submarine’s further fate remained unknown. In total, from August 6 to the end of 1941, Bulgarian S-328s conducted 68 combat sorties, including 41 for anti-submarine convoy escort, ensuring the passage of 73 transport vessels.

At the initiative of the German command, fighters from the 6th Fighter Regiment were also involved in the air cover of convoys sailing along the Bulgarian Black Sea coast from October 10. For this purpose, the 682nd Squadron under Lieutenant Krystio Atanasov was transferred to Balchik airfield, and the 692nd Squadron of Lieutenant Dimitar Lazarev was sent to Sarafovo airfield. Both squadrons were equipped with German Bf-109E fighters. In the autumn of 1941, fifteen Bulgarian pilots were sent to Germany for flight training as attack aircraft pilots. First, they completed an initial course at the 1st Elementary Dive-Bomber Aviation School (Sturzkampffliegervorschule 1) at Bad Aibling airfield, 44 km southeast of Munich, and then arrived at the 1st Dive-Bomber Aviation School, located at Wertheim airfield, 82 km northeast of Mannheim. The head of the aviation school at that time was Major Hubertus Hitschhold, who on July 21, 1940, was awarded the Knight’s Cross for his successful leadership of I./StG2 during combat operations in Belgium, Holland, and France.

After completing their training in Germany, Bulgarian pilots were sent to Italy, where they were to undergo a practical training course. However, the Bulgarian command did not allow them to be involved in actions against Allied ships in the Mediterranean Sea, as the Italians desired, and so the Bulgarian pilots were soon recalled and sent to Graf Ignatievo airfield, approximately 25 km north of Plovdiv, where the 2nd Assault Air Regiment was subsequently formed.

In the winter of 1941-42, Germany transferred nine Bf-109E-7s to Bulgarian aviation, but then the supply of German aircraft completely ceased. This was apparently primarily due to Bulgaria’s non-participation in combat operations, which at that time were taking place far from its territory. However, the events of June 12, 1942, showed that the military situation in Europe was beginning to change fundamentally.

Air Defense Against the Allies (1942-1944)

On the evening of June 11, 13 B-24D bombers from the HALPRO group took off from Fayid airfield in Egypt. Throughout the night, the “Liberators” flew individually across the Mediterranean Sea and, after flying over Turkish and Bulgarian territory, reached Romania early on June 12 and attacked the oilfields in the Ploiești area. For the Bulgarian air force command, the appearance of American strategic bombers over the country came as a complete surprise, and therefore it was unable to organize their interception.

As the B-24Ds returned, Avia B-534 fighters from the 612th and 622nd Fighter Squadrons were scrambled. Both squadrons were part of the 1st Air Group of the 6th Fighter Regiment under the command of Colonel Vasil Valkov and were based at Vrazhdebna and Bozhurishte airfields near Sofia. However, Bulgarian pilots could do nothing, as their outdated biplanes could not even catch the heavy four-engine “Liberators”: the Avia B-534 fighter had a maximum speed of 415 km/h, while the B-24D bomber could reach a speed of 488 km/h.

Following the events of June 12, the German military air mission in Sofia demanded better coordination of defensive actions from the Bulgarian air force, while promising to expedite the delivery of modern fighters. However, the Reich Air Ministry in Berlin apparently had a somewhat different opinion, and therefore only in December 1942 decided to send 16 Bf-109G-2 fighters to Bulgaria. On January 6, 1943, Bulgarian War Minister Nikola Mihov met with Adolf Hitler, where the latter firmly promised to provide Bulgaria with modern weaponry.

The Wehrmacht High Command’s report on the results of the Bulgarian War Minister’s visit stated, among other things: “The anti-aircraft defense [of Bulgaria] is still very weak. Especially little has been done to protect the civilian population. Support is needed, particularly through the supply of anti-aircraft guns… The Bulgarian army and air force are currently prepared only for defense and are not suitable for attack… The needs of Bulgarian aviation will be presented separately by the air attaché to the Luftwaffe High Command…” However, in practice, nothing changed, and Germany was in no hurry to send modern aircraft to Bulgaria. In the winter of 1942-43, only 12 Ar-196 seaplanes arrived there, which were sent to the 161st Coastal Squadron, stationed on the Black Sea coast. In March 1943, Bulgarian aviation finally received the 16 Bf-109G-2s promised the previous December. Then, in the summer, 13 more such fighters arrived in Bulgaria.

After German troops occupied the territory of France, previously controlled by the Vichy government, on November 11, 1942, the Luftwaffe acquired a total of 1,876 French aircraft. Among them were 246 Dewoitine D.520 fighters and 37 Bloch 210 bombers, which were initially intended for transfer to Bulgarian aviation. But Bulgaria’s hopes for a substantial modernization of its air force were once again not destined to come true—most of these aircraft ended up in Luftwaffe flight schools, and some were transferred to the Italians. As a result, Bulgaria was left with only 96 D.520 fighters, and by August 1943, not a single one had yet been transferred to Bulgarian aviation.

In the summer of 1943, forty Bulgarian pilots arrived in France at Nancy airfield. The training and combat squadron JG107, under the command of Major Georg Meyer, was stationed there, where the Bulgarians underwent a re-training course on the D.520 fighter. Simultaneously, 63 Bulgarian technical personnel were sent to the 5th Luftwaffe Technical School (Fl.Tech.Schule 5) in Wichau.

At 07:00 on August 1, 1943, approximately 170 B-24D bombers took off from airfields in North Africa near Benghazi. Operation “Tidal Wave” began, aiming to raid Romanian oilfields in the Ploiești area. Around noon, blips from four groups of enemy aircraft appeared on the screen of the German FuG65 “Wurzburg-Riese” radar station, installed on Cherni-Vrykh mountain, 15 km south of Sofia. The Germans urgently transmitted information about the approaching bombers to the Bulgarian air force command.

To intercept the bombers, which were presumed to be heading for the Bulgarian capital, Avia B-534 fighters from the 612th and 622nd Squadrons of the 1st Air Group took off from Vrazhdebna and Bozhurishte airfields near Sofia, while ten Bf-109G-2s from the 3rd Air Group took off from Marnopole airfield near Karlovo, 118 km east of Sofia. When it became clear that the American “Liberators” were heading not for Sofia but northeast towards the Romanian border, the Bulgarian fighters could no longer catch them.

Approximately two hours later, reports began to arrive from ground observation posts about small groups of four-engine aircraft reappearing over Bulgaria. These were B-24s returning after the raid on Ploiești, and at 15:00, Bulgarian fighters took to the air again. For the pilots of the hopelessly outdated Avia B-534 biplanes, armed with four 7.92-mm machine guns, an encounter with the “Liberators,” each carrying ten 12.7-mm machine guns, was extremely risky, if not simply suicidal. The American bombers, stripped of bombs and most of their fuel, easily outran the Bulgarian biplanes. Only a few pilots from the 1st Air Group, diving from a high altitude, managed to get close and fire at the “Liberators.” One of the 98BG gunners later recalled: “I rubbed my eyes in amazement – what kind of war was this? World War I? It looked like a time warp. Suddenly these little biplanes appeared that looked generally like old Curtiss ‘Hawks.’ I was amazed to notice that they fired at us before disappearing again.”

Nevertheless, the Americans could not avoid losses over Bulgaria. A flight of Bf-109G-2s from the 3rd Group of the 6th Fighter Regiment, led by Lieutenant Stoyanov, intercepted a group of 18 B-24Ds between the towns of Ferdinand (now Montana) and Vratsa, located 78 km and 58 km north of Sofia, respectively. As a result, Stoyanov and Second Lieutenant Ivan Bonev each shot down one aircraft, which fell in the area of the villages of Kokartzhi and Karakash near Trun. Two more “Liberators” were damaged and, leaving behind smoky trails, broke formation.

The bombers were then attacked by a second pair of Bf-109G-2s from the 682nd Squadron of the 3rd Air Group, piloted by Second Lieutenants Hriste Krastev and Petar Bochev. Bochev shot down B-24D 41-24121 “Let er Rip” from the 93 BG, which crashed near Slivnitsa, 30 km northwest of Sofia. Only three members of its crew managed to parachute out and were subsequently captured. The crew members of B-24D 41-11840 “The Witch” from the 98 BG, shot down by Krastev, were luckier, and all survived. The aircraft fell in Serbian territory in the area of Vladishki Han, 35 km from the Bulgarian border. Six American airmen were captured, and four – co-pilot Daryl P. Epp, bombardier Major R. Gillette, radio operator Dalwe G. Husley, and tail gunner Walter D. Hardiek – managed to evade capture and join Yugoslav partisans. On August 7, Bulgarian Tsar Boris III personally presented officers’ medals “For Bravery” to Lieutenant Stoyanov and Second Lieutenant Bonev at his palace in Sofia.

On August 28, 1943, Boris III, whose figure had united all Bulgarians for many years, suddenly died. His underage son, Simeon II, became the new Tsar of Bulgaria, and three elected regents began to govern the country on his behalf. From this moment, a process of gradual erosion of the entire political system began in the country. However, this did not affect the strengthening of Bulgarian aviation. First, Reichsmarschall Göring announced that he would transfer 48 Bf-109Gs to Bulgaria as a gift, and then in September, a solemn ceremony took place at Karlovo airfield for the transfer of the first 48 D.520 fighters. In addition, in the autumn of 1943, the Bulgarians received 12 Ju-87R-2/R-4s, which they then named “Shchuka” (Pike).

Meanwhile, the war was approaching Bulgaria’s borders. On October 21, about 40 American aircraft appeared over Skopje, the center of Macedonia, and Bulgarian fighters managed to shoot down one P-38. On November 14, aircraft of the US 12th Air Force – 91 B-25s under the cover of 40 P-38s – carried out the first raid on Sofia. The air raid alarm was sounded late, and fighters of the 2nd and 3rd Air Groups could only attack them during their withdrawal. Second Lieutenant Mihail Grigorov shot down a P-38, which crashed in Macedonian territory near Debar, 90 km southwest of Skopje, while Lieutenant Nikolay Yordanov, Second Lieutenant Petar Bochev, and Sergeant Major Alexandr Petkovsky damaged one B-25 each. On the “Mitchell” attacked by Bochev, one engine caught fire, but the crew managed to extinguish the flames and reach their airfield. At the same time, the Bulgarians lost one fighter and its pilot, and two other aircraft, having sustained damage, made forced landings.

The next raid on Sofia took place a week later, on November 24, when out of 60 B-24D bombers from the US 15th Air Force, only 17 managed to reach their targets. This time, Bulgarian fighters were ready for the raid – 24 D.520s from the 2nd Air Group took off from Vrazhdebna airfield, and 16 Bf-109G-2s from the 3rd Air Group took off from Bozhurishte airfield.

Captain Chudomir Toplodolsky and Sergeant Major Hriste Tsankov shot down two “Liberators” over Macedonia, which crashed respectively near Strumica and west of Bogomila, 30 km southwest of Titov Veles. Toplodolsky then attacked and damaged another bomber in the area of the Bulgarian city of Dupnitsa. Two B-24Ds sustained heavy damage as a result of attacks by Lieutenant Stoyan Stoyanov and Second Lieutenant Mihail Grigorov, while Second Lieutenant Mihail Utsunov and Sergeant Major Nikola Kralichev damaged two P-38s. At the same time, the Bulgarians lost one fighter and three more made forced landings.

On December 10, 31 B-24Ds participated in the third raid on Sofia, again covered by P-38s. To meet them, 16 D.520s from the 1st Air Group took off from Karlovo airfield, six D.520s from the 2nd Air Group from Vrazhdebna airfield, and 17 Bf-109G-2s from the 3rd Air Group from Bozhurishte airfield. Lieutenant Assen Kovachev, Lieutenant Lyuben Kondakov, and Sergeant Major Petkovsky managed to damage three B-24Ds, while Captain Toplodolsky, Lieutenant Stoyanov, Second Lieutenant Utsunov, and Second Lieutenant Marin Tsvetkov damaged four P-38s. The Americans then claimed to have shot down eleven “Dewoitines,” losing only one “Lightning,” but in reality, the Bulgarians lost only one D.520 then. The last raid on Sofia in 1943 occurred on December 20. It involved 50 B-24s from the US 15th Air Force, escorted by 60 P-38s. 36 D.520s from the 1st and 2nd Air Groups and 20 Bf-109G-2s from the 3rd Air Group took to the air, meeting the enemy approximately 65 km southwest of Sofia.

On that day, in battles over Macedonia and Bulgaria, seven “Lightnings” were shot down—credited to Captain Toplodolsky, Lieutenants Nikolay Yordanov and Viktor Pavlov, Second Lieutenants Nikola Nachev and Georgi Kyumyurdzhiev, Officer Cadet Georgi Atanasov, and Sergeant Major Tsankov. In addition, Second Lieutenant Tsvetkov damaged another P-38.

The Americans also lost four B-24Ds, two of which were credited to Lieutenant Dimitar Spisarevsky. First, he shot down one with his onboard weapons, and then rammed a second “Liberator” with his Bf-109G-2. Both aircraft, engulfed in flames, crashed in the area of Pancherevo village, and Spisarevsky was killed. As a result of Second Lieutenant Stefan Marinopolsky’s attack, another aircraft exploded in the air and crashed west of the Serbian town of Bosilegrad, a few kilometers from the Bulgarian border. The fourth B-24D shot down was credited to Second Lieutenant Gencho Dimitrov. In addition, the same Dimitrov, Lieutenant Stoyanov, Second Lieutenant Nedelcho Bonchev, and Sergeant Major Petkovsky damaged five more “Liberators.”

The Americans claimed to have shot down 28 Bulgarian fighters on December 20. However, in reality, the Bulgarians, in addition to Lieutenant Spisarevsky’s Bf-109G-2, lost only one aircraft, which was shot down by a P-38 while attacking “Liberators,” and its pilot, Second Lieutenant Kyumyurdzhiev, was killed. In addition, two more Bulgarian fighters, having sustained damage, made forced landings.

The American bomber raids severely affected the morale of the Bulgarian civilian population. On the eve of Christmas, the German ambassador in Sofia, Adolf Heinz Beckerle, reported to the Reich Foreign Ministry in Berlin: “Foreign Minister Shimanov today asked me to come to him and explained the Bulgarian government’s concerns regarding further enemy air raids. After the last raid, it [the government] is very concerned that Bulgarian cities, and Sofia in particular, due to a lack of cellars and other shelters, are very vulnerable to air raids, and that the Bulgarian population does not have the same resilience as we Germans, and that new raids will have an unpleasant effect on the morale of Bulgarian society. Therefore, the Bulgarian government asks the German government to consider the possibility of sending one hundred German fighters to Sofia with corresponding ground personnel. In addition, it asks for the immediate delivery of 50 ‘Messerschmitt’ fighters. The only defense against enemy raids are their fighters, which indeed decisively attack the enemy, but which after each sortie become fewer and fewer. He [Shimanov] also drew my attention to how psychologically important it is if the Bulgarian people, thanks to the help of German aviation, do not feel defenseless against enemy air raids.”

This time, Germany took Bulgaria’s request seriously. The Luftwaffe sent one fighter group to defend Sofia, began retraining fifty Bulgarian pilots, and provided additional material assistance to Bulgarian aviation. During January-February 1944, it was supplied with 40 Bf-109G-6s, 25 Bf-109G-2s, 32 Ju-87D-3/D-5s, 10 FW-58s, 9 Bu-131s, and 5 Ar-96Bs. However, most of the new “Messerschmitts” arrived in Bulgaria after “Black Monday.” On Monday, January 10, 1944, Sofia was subjected to two raids. Around noon, 180 B-17s appeared over the city under powerful fighter cover, and in the evening it was attacked by 80 British bombers. As a result, 4100 buildings were destroyed in Sofia, 750 people were killed, and 710 were wounded. 70 Bulgarian and 30 German fighters participated in repelling the raids, managing to shoot down eight bombers and five P-38s.

Bulgarian pilots attacked the “Flying Fortresses” formation over the Vitosha mountain range. Lieutenant Zemen Dimitrov, Second Lieutenants Emil Balgaranov, Georgi Gochev, Ivan Ivanov, and Dimitar Batchvarov each shot down one bomber, while Second Lieutenants Emil Stoichev, Vladimir Alexandrov, and Sergeant Major Tsvyatko Zagorsky damaged three more B-17s. Simultaneously, in fierce battles with “Lightnings,” Bulgarian pilots achieved three more victories. Lieutenant Stoyanov attacked one of the P-38s twice at an altitude of 100-150 meters. Finally, he managed to score hits and, smoking, the “Lightning” crashed to the ground a few moments later. After a long “one-on-one” fight, Captain Toplodolsky managed to shoot down a second P-38, which fell near a small village close to Sofia. The third fighter was credited to Second Lieutenant Gencho Dimitrov.

In addition, Lieutenant Kovachev, Second Lieutenants Stoichev, Nikola Nachev, Petar Petrov, and Paniu Kraevsky, Sergeant Majors Stanush Stanushev, and Stefan Kontsov managed to damage seven more P-38s. The fighters attacked by Kovachev, Stoichev, Nachev, and Kraevsky caught fire, but the American pilots managed to extinguish the flames and reach their airfields. Later that evening, Lieutenant Vasil Shishkov, paired with Officer Cadet Stefan Iliev, shot down a four-engine British “Stirling” bomber, which crashed near Kladnitsa village near Radomir. The Americans claimed to have shot down at least 31 fighters on January 10, 1944, which was a clear absurdity, as Bulgarian aviation as a whole lost only 24 fighters in combat in 1943-44, and another 18 made forced landings after sustaining damage.

The January 10 raids had the most severe consequences for the Bulgarian capital. Approximately three hundred thousand residents left the city, schools were closed, government institutions ceased operations, and most officials also left the city. Even two weeks later, life in Sofia had still not returned to normal. On January 23, the German embassy reported to Berlin by telegram: “Recovery efforts are progressing extremely slowly. Water and electricity are still supplied only partially, the telephone is not working. Most shops are closed.”

Only in February did Sofia’s exhausted population finally feel that city life was beginning to normalize. However, on March 16, 17, and 29, the city was subjected to new raids, but the most powerful raid occurred on March 30. It involved 450 heavy bombers—American B-17s and B-24s, and British “Halifaxes”—escorted by 150 P-38s. As a result of the bombing, about two thousand fires were reported in Sofia. To repel the raid, the command of the 6th Fighter Regiment launched 73 aircraft: 28 D.520s led by the commander of the 1st Air Group, Lieutenant Bogdan Iliev, took off from Karlovo airfield; 6 D.520s and 19 Bf-109G-6s from the 2nd Air Group, led by Lieutenant Bonchev, took off from Vrazhdebna airfield; and 20 Bf-109G-6s, led by the commander of the 3rd Air Group, Lieutenant Stoyanov, took off from Bozhurishte airfield. In addition, four Avia B-534 trainers also took off and, surprisingly, managed to damage one “Liberator.”

Second Lieutenant Hristo Kostakiev shot down two B-17s at once. The aircraft exploded in the air, and their debris fell near Kosharevo village, close to Breznik, 35 km west of Sofia. Lieutenant Nedelcho Bonchev was credited with a “Flying Fortress” that crashed west of Pernik, 25 km southwest of the Bulgarian capital. Second Lieutenant Viktor Atanasov shot down the fourth bomber, which crashed and burned northwest of Kyustendil, 72 km southwest of Sofia. East of Kyustendil, the pair Second Lieutenant Emil Stoichev – Second Lieutenant Assen Gigov damaged one B-17. Then the same was done by the pair Captain Hristo Atanasov – Second Lieutenant Dimitar Sofirov. The pair Second Lieutenant Ivan Stefanov – Sergeant Major Tsvetan Gruev disabled two engines on another bomber, which, leaving its group’s formation, turned back. One bomber each was damaged by Captain Nikola Boshnakov, Lieutenants Lyuben Kondakov and Boris Damev, and Second Lieutenants Hristo Petrov, Marin Tsvetkov, and Mikhail Grigorov.

Since on March 30, during the raid on Sofia, the Allies lost eight bombers, this means that out of nine damaged aircraft, four could not make it back to their airfields and crashed somewhere outside Bulgarian territory. Second Lieutenant Gencho Dimitrov shot down a P-38, whose pilot, parachuting out, was captured. The second “Lightning,” shot down in the area of Plachkovitsa mountain, was credited to Lieutenant Bogdan Iliev. Although Lieutenant Vasil Shishkov was not credited with a victory that day, it was probably after his attack that the Americans lost a third “Lightning,” which crashed somewhere in the Pirin mountains northeast of Kyustendil. In addition, during the battle in the Dupnitsa-Radomir area, Sergeant Major Atanas Mateev managed to damage another P-38. At the same time, on March 30, the Bulgarians lost five fighters and two more made forced landings. Three pilots were killed, and one – Second Lieutenant Kassianov – was shot by Americans while parachuting down and sustained a serious injury.

On April 4, 1944, Second Lieutenant Petar Petrov from the 2nd Air Group distinguished himself. He shot down one B-24, which then crashed in the area of the Serbian city of Zajecar, 10 km from the Bulgarian border. Another “Liberator,” as a result of his attack, sustained heavy damage and, catching fire, left its group’s formation. On April 5, twenty Bf-109G-6s from the 3rd Air Group intercepted American bombers returning to Italy after a raid on the Ploiești oilfields, and Officer Cadet Veseliy Terziev managed to shoot down one of them. The crew managed to parachute out of the burning aircraft, which crashed in the Kule-Male area. In addition, Second Lieutenants Gencho Dimitrov and Mihail Banov damaged two P-38s. At the same time, the Bulgarians lost one “Messerschmitt.”

On April 17, 1944, at 11:35, air raid sirens sounded again in Sofia. 350 B-17s, flying in four “waves,” approached the city, escorted by 100 fighters. It was during the repulsion of this raid, which was the tenth raid on Sofia, that Bulgarian aviation suffered its heaviest losses since the beginning of the war. The first to take to the air were aircraft of the 2nd Air Group – 16 Bf-109G-6s and 7 D.520s – which immediately engaged in battle. However, it turned out that on that day, the escort fighters involved in the raid were not the familiar twin-engine P-38s but P-47s and P-51s, which the air observation service had initially mistaken for German fighters. As a result, when the Bulgarians realized their mistake, it was already too late, and the 2nd Air Group, caught by the unexpected appearance of “Mustangs,” immediately lost seven “Messerschmitts.”

During the battle, Second Lieutenant Nedelcho Stoyanov managed to shoot down a P-51, and the commander of the 2nd Air Group, Lieutenant Bonchev, rammed a B-17 in the Pernik area. A few moments later, the “Flying Fortress” exploded in the air, and its burning wreckage, along with the debris of the “Messerschmitt,” fell on Krapec village, while Bonchev himself survived, descending to the ground by parachute. By this time, Bf-109G-6s from the 3rd Air Group had also entered the battle, as well as four Avia B-135 training fighters. Captain Nikola Boshnakov, Lieutenant Assen Kovachev, Lieutenant Nikolay Yordanov, Second Lieutenant Vladimir Alexandrov, and Sergeant Major Dako Dakov managed to damage one B-17 each, but this could no longer change the overall situation. In total, on April 17, the Bulgarians lost nine fighters, with six pilots killed, and in addition, four more aircraft, having sustained damage, made forced landings. As of May 1, 1944, Bulgarian aviation comprised 500 aircraft and 13,500 personnel, including 250 aircraft and 5,400 personnel in combat units. The core of Bulgarian aviation’s combat power consisted of 145 Bf-109Gs, which bore the brunt of the air battles from May to August 1944. The “Messerschmitts” attacked Allied aircraft carrying out raids on Bulgarian cities, as well as those flying over Bulgarian territory en route from Italy to Romania and back.

On May 5, the pair Captain Marin Petrov-Lieutenant Zahari Planinsky, as well as Lieutenant Nikola Kolev, during an attack on a group of four-engine bombers, managed to heavily damage two aircraft. On each of them, two engines were knocked out, and the bombers left their combat formation. On May 18, Second Lieutenant Evgeniy Tonchev of the 682nd Squadron of the 3rd Air Group shot down a B-24D, which crashed in the area of the Serbian city of Prokuplje. Second Lieutenant Ivan Bonev, attacking another “Liberator,” managed to damage both of its right engines. The bomber was forced to leave its group’s formation and, after being “finished off” by Sergeant Major Dako Dakov, crashed to the ground in the Pristina area. On June 11, Second Lieutenants Marin Tsvetkov and Todor Rozev shot down two B-24s, which crashed respectively in the Gorna-Kreme area near Vratsa and near Koshare village close to Pernik. Second Lieutenant Ivan Bonev was credited with a P-38 that burned in the Sredne-gorne area, 65 km east of Sofia. However, Bonev himself was killed in the same battle when his Bf-109G-6 was in turn shot down by “Lightnings.”

On June 23, Bulgarian Bf-109G-6s intercepted B-17s and B-24s from the US 15th Air Force over Macedonia, returning to Italy after another raid on the Ploiești oil refineries and Giurgiu port on the Danube, 60 km south of Bucharest. Lieutenant Stoyan Stoyanov managed to shoot down one “Liberator,” which exploded in the air west of Skopje. As a result of attacks by Lieutenant Boris Damev, Second Lieutenant Evgeniy Tonchev, and Officer Cadet Toshko Hristov, three more bombers sustained heavy damage. Two B-24s, with one engine each on fire, were forced to leave their formation. In the area of Karlovo airfield, four Bulgarian “Messerschmitts” attacked B-17 42-5951 “Opissonya” from the 34IBS 97BG, which had previously been damaged over Romania. The bomber crew included: first pilot and commander Second Lieutenant Edwin Anderson, co-pilot Second Lieutenant William Simons, navigator First Lieutenant Robert Newsom, bombardier Second Lieutenant David Kingsley, flight engineer Sergeant John Meyer, radio operator Sergeant Lloyd Kane, tail gunner Sergeant Michael Sullivan, ball turret gunner Sergeant Stanley Kmiec, and waist gunners Sergeants Martin Hettinga and Harold James.

While approaching Ploiești, the 97BG bombers were intercepted by approximately twenty Bf-109Gs and FW-190As. After shooting down two B-17s in a short period, the German fighters ceased attacks as the bombers entered the range of anti-aircraft batteries surrounding Ploiești. As the “Flying Fortresses” proceeded on their bombing run, Second Lieutenant Anderson’s aircraft took a direct hit from an anti-aircraft shell, disabling engine No. 1 on the left wing and leaving a 12-inch hole. A few seconds later, an explosion from a second anti-aircraft shell, detonating in close proximity to the tail section, damaged the tail fin and knocked out the bomber’s oxygen system. Despite this, Anderson and Newsom maintained the “Flying Fortress” on its bombing course until Kingsley released bombs on the planned target.

After the damaged bomber, turning on its return course, left the anti-aircraft fire zone, it attracted the attention of several “Messerschmitts.” During renewed attacks, the second engine on the left wing was damaged, trailing a plume of white smoke. Simultaneously, fragments from several 20-mm shells that exploded in the aircraft’s tail section severely wounded tail gunner Sergeant Sullivan in his right shoulder and arm. However, the most unpleasant thing was that the fragments had literally riddled his parachute, rendering it unusable.

Severely wounded Sullivan managed to crawl from the tail of the “Flying Fortress” to the central fuselage, where waist gunners Sergeants Hettinga and James tried to provide him with first aid. However, they soon realized they could not stop the bleeding and therefore called for help from Second Lieutenant Kingsley, who had special medical training. Applying a tourniquet and splint, Kingsley managed to stop the bleeding from Sullivan’s wounds. By this time, as a result of a new “Messerschmitt” attack, ball turret gunner Sergeant Kmiec also received a minor wound.

Flying southwest, the B-17 soon found itself over Bulgarian territory. It was losing altitude, so Second Lieutenant Anderson ordered the crew to jettison everything they could to lighten the aircraft as much as possible. Soon, a pair of P-51Ds appeared in the sky, and Anderson and his crew had hope for a successful completion of the sortie. However, their joy was short-lived, as the “Mustang” pilots reported that they had little fuel left and would not be able to escort the bomber to Italy. After some time, the “Flying Fortress” flew in close proximity to Karlovo airfield. At that moment, in Karlovo, in addition to Bulgarian fighters, a flight of German Bf-109G-6s was also stationed. Luftwaffe pilots had arrived there to help train Bulgarian fighter pilots. Upon receiving the report of the American bomber, Major Helmut Kuhle, who was in charge of the training, ordered four German and four Bulgarian “Messerschmitts” to take to the air.

The lone B-17, whose tail turret was also disabled, became easy prey for the fighters. When they caught up with the bomber, the Luftwaffe pilots gave the Bulgarians the right to finish it off themselves. As a result, four Bulgarian Bf-109G-6s, one after another, approaching from behind, fired at close range into the “Flying Fortress” virtually unopposed. Whole fragments of the skin began to detach from it, and two more crew members were wounded. A few seconds later, the bomber’s fate was sealed, and Anderson ordered his crew to abandon the aircraft.

Kingsley dragged the wounded Sergeant Sullivan to the open bomb bay. Since Sullivan’s parachute was damaged, Kingsley put his own on him and helped him jump from the falling B-17. A short time later, the bomber, along with Kingsley who remained on board, crashed to the ground. Second Lieutenant David Kingsley sacrificed his life to save a wounded crew member and was posthumously awarded the highest US military honor, the Medal of Honor. A Bulgarian family of three, resting in the vicinity of Karlovo that day, became an accidental victim of the “Flying Fortress” crash.

On June 24, Bulgarian pilots shot down four more bombers. The aircraft that crashed in the Samokov area, 42 km south of Sofia, was credited to Second Lieutenant Petar Petrov. Lieutenant Stoyan Stoyanov, Second Lieutenant Mihail Utsunov, and Officer Cadet Kiril Stoyanov jointly shot down a B-17, whose wreckage was also found in the Samokov area. Another aircraft, which crashed in the area of the Serbian city of Negotin, 10 km west of the junction of the borders of Bulgaria, Yugoslavia, and Romania, was shot down by the combined efforts of Lieutenant Damev, Second Lieutenant Tsvetkov, and Officer Cadet Yato Petkov. The fourth bomber, which crashed in the mountains in the area of Bogdan Peak, was credited to Sergeant Major Tsvyatko Zagorsky of the 3rd Air Group.

However, then 14 Bf-109G-6s from the 3rd Air Group were unexpectedly attacked by more than forty P-38s south of Samokov. As a result, two “Messerschmitts” were shot down, Sergeant Major Zagorsky was killed, and Second Lieutenant Todor Rozev managed to parachute out. Two more aircraft made forced landings in the Ihtiman area, located 47 km southeast of Sofia, and Second Lieutenant Hristo Krastev was severely wounded. On July 15, Second Lieutenant Hristo Kostakiev of the 3rd Air Group attacked a four-engine bomber. However, he did not manage to see its results, as his Bf-109G-6 was hit, and oil leaking from the damaged engine completely covered the cockpit canopy. Since no wreckage was found in the area indicated by Kostakiev, most likely the bomber suffered only minor damage.

On July 22, 1944, Bulgarian “Messerschmitts” shot down two four-engine bombers over Serbia. Second Lieutenant Petar Bochev was credited with an aircraft that crashed in the mountains near Babushnitza village, 49 km southeast of Nish. The other bomber, which crashed east of Kragujevac, was shot down by the combined efforts of Captain Chudomir Toplodolsky, Sergeant Major Nikola Kralichev, and Officer Cadet Dimitar Somov. In addition, Second Lieutenant Marin Tsvetkov damaged another bomber, which left its group’s formation and, losing altitude, turned towards Bosilegrad. On August 10, Captain Krystio Atanasov and Second Lieutenant Petar Bochev shot down a four-engine bomber in the area of Nishka Banya village, located 8 km southeast of Nish. Another aircraft, as a result of the attack by Second Lieutenant Petar Bochev’s and Sergeant Major Alexandr Petkovsky’s “Messerschmitts,” sustained heavy damage and left its formation. Probably, this aircraft was finished off by Sergeant Major Stefan Kontsov, who attacked the damaged bomber flying alone. The aircraft began to lose altitude and crashed on Bulgarian territory near Samokov.

On August 17, Second Lieutenant Petar Bochev heavily damaged a four-engine bomber, which crashed near the Macedonian village of Jostovo next to Skopje. Six more bombers sustained damage and were forced to leave their unit’s combat formations as a result of attacks by Captain Atanasov, Lieutenant Damev, Second Lieutenants Marin Tsvetaev, Nikola Valchev, and Petar Manolev, as well as Officer Cadet Kiril Stoyanov. On August 26, 1944, Bulgarian fighters engaged Allied aircraft for the last time. Captain Atanasov, Second Lieutenant Petar Bochev, and Officer Cadet Nikola Takov jointly shot down a four-engine bomber, which crashed in Serbian territory near Vladishki Han. Lieutenant Stoyan Stoyanov was credited with a P-38 that crashed southeast of the Bulgarian village of Nefela in the Vratsa area. In addition, during the battle, Second Lieutenants Dimitar Sofirov and Georgi Georgiev, as well as Officer Cadet Kiril Stoyanov, managed to damage three more “Lightnings.”

In total, from May 18 to August 26, 1944, Bulgarian pilots shot down 15 four-engine bombers and four P-38s. At the same time, Bulgarian aviation’s combat losses during this period amounted to eight aircraft—four of them were shot down, and four made forced landings. On June 11, one of the Bulgarian pilots, who parachuted from a downed aircraft, was shot by Americans in the air. During 1943-44, Allied aviation conducted about 23,000 combat sorties over Bulgaria. 186 Bulgarian settlements were subjected to air strikes, on which 45,000 high-explosive and incendiary bombs were dropped. As a result of the bombings, 12,000 buildings were destroyed, 4,208 people were killed, and 4,744 were wounded. The Bulgarian anti-aircraft defense, and primarily the pilots of the 6th Fighter Aviation Regiment, shot down 65 Allied aircraft and damaged another 71. During combat sorties over Bulgaria, the Allies lost 585 pilots and crew members—329 people were captured, 187 died, and 69 died of wounds in hospitals. At the same time, Bulgarian aviation’s own losses amounted to 24 fighters, 18 more aircraft made forced landings, and 19 pilots were killed.

Switching Sides and Post-War Repressions (1944-1945)

On September 5, 1944, the Soviet Union declared war on Bulgaria, and on September 8, Soviet troops entered its territory. The Bulgarian army received orders not to resist, and Soviet troops quickly occupied the northeastern part of the country and its two main ports—Varna and Burgas. On the night of September 8-9, a military coup took place in Sofia. Units of the capital garrison, led by officers acting on orders from the newly created Fatherland Front, occupied all key city facilities and arrested the previous government. As a result, on September 9, a Fatherland Front government was formed in Bulgaria, headed by Kimon Georgiev, and on September 16, Soviet troops entered Sofia.

Already on September 10, 1944, the Fatherland Front government declared war on the Third Reich and its allies. The 1st, 2nd, and 4th Bulgarian armies, numbering about 500,000 personnel, began an offensive in Serbia in the direction of Nish, and in Macedonia, towards Skopje. The Allied command set them the task of blocking the retreat routes for German troops located in Greece. The actions of ground units were actively supported by Ju-87D-5s from the 1st Group of the 2nd Bomber Regiment and Do-17s from the 1st Group of the 5th Bomber Regiment. To ensure the necessary freedom of action, three Bf-109G-6s led by Lieutenant Boris Damev carried out a strafing attack on Nish airfield, destroying six German “Messerschmitts” on the ground at once.

Within a month, Bulgarian troops managed to occupy Macedonia and the southeastern regions of Serbia. As a result, Wehrmacht units, cut off in Greece, surrendered to the British. In total, during the battles in Serbia, Macedonia, and Greece, Bulgarian aviation aircraft conducted 3,744 combat sorties by December 12, 1944, during which 694 armored vehicles and automobiles, 25 artillery batteries, 23 locomotives, and 496 railway wagons were destroyed. In air battles and on the ground, Bulgarian pilots destroyed 25 Luftwaffe aircraft. At the same time, Bulgarian aviation lost 15 aircraft, 18 pilots, and crew members.

Subsequently, the 130,000-strong 1st Bulgarian Army was redeployed to Hungary and, from March 6 to 19, 1945, participated alongside Soviet troops in fierce battles in the Lake Balaton area, where German tank divisions attempted a counteroffensive. In April 1945, units of the 1st Bulgarian Army entered Austrian territory and met units of the British 8th Army in the Klagenfurt area. In total, in 1944-45, Bulgaria lost about 30,000 personnel in battles against the Third Reich and its allies.

After the communist-controlled Fatherland Front government came to power in Bulgaria, mass repressions began against officers of the former royal army and former royal officials. Many of them were simply killed immediately after September 9, 1944; thousands were arrested and sentenced to various terms of imprisonment, and 2,370 people were sentenced to death. In total, according to approximate estimates, about fifty thousand people became victims of political repression in Bulgaria.

The wave of repressions also swept through Bulgarian aviation. Immediately after the communists came to power, the following were killed: Colonel Todor Rogev, commander of the 2nd Assault Air Regiment Hristo Iliev, commander of the recently formed 4th Air Group of the 6th Fighter Regiment Captain Marin Petrov, Captain N. Videnov, Lieutenant Vasil Shishkov, and Second Lieutenant Shelev. In October 1944, the commander of the 6th Fighter Regiment, Colonel Vasil Valkov, was arrested. On March 13, 1945, he was sentenced to death and executed the same day. To this day, the fate of the commander of Bulgarian aviation, Major General Dimitar Ayranov, remains unclear. He was sentenced to life imprisonment, which was later commuted to five years in prison. Nevertheless, Ayranov never regained freedom; he simply disappeared without a trace.