The sky is blue, the sea is blue, the white clouds are green, the sun is shining, it is a good weather, and it is also a good time for the countries of the Balkan Peninsula to start combat operations. The navy of the Five Powers Coalition cruised back and forth in the Mediterranean, and with the roaring sound of artillery, the Greek navy cowered in the harbor and did not dare to meet it head-on.

Minervena, located 150 kilometers south of Sarajevo, became the forward position of the German, British, French, Italian, and American forces in mid-May, and as the war progressed, it became the only large rear of Yugoslavia.

Ten days ago, the Greek army was attacking and advancing northward, because it did not listen to Eric's advice.

As a result, the forces of the Five Powers were sent together to blockade the city at sea and on land, and the Greek invading army was attacked on both sides and was finally forced to be trapped in the isolated city of Sarajevo in the north.

Over the past few days, the Greek army, which had rushed to the aid of Albania, organized several counterattacks, but they were all blocked by the coalition forces south of Podgorica.

The negotiation agreement with Berlin was not reached, and the Greek army, which had been besieged for many days, was forced to make a desperate gamble, forming a number of death squads to desperately launch a counter-charge against the coalition positions, but the battlefield was like a knife cut off, and as soon as it broke through a gap, it was immediately blocked by the influx of coalition troops.

Outside Sarajevo, the coalition and the Greek army formed a game of cat and mouse, most of the time, the coalition artillery fire was like an eye, directly poured into the Greek position, red flames and white smoke screens in the air to draw bullet marks, accompanied by the sound of "boom", dull explosions continued one after another, and the casualties on the Greek positions were very heavy.

The Greek army, which lacked artillery and other heavy weapons, faced with the tight encirclement of the coalition forces, obviously could only take the initiative to attack by fighting bayonets, in order to find an opportunity to break through, but the coalition forces repeatedly avoided the edge of the Greek army, deliberately opened the hole to let the Greek army drill, and then used mortars to gather and annihilate.

The fortifications occupied by the coalition forces were relatively rudimentary, but after the heavy setbacks of the Greek army, they could no longer organize a decent charge, and they were helpless in the face of the provocation of the five-nation coalition forces.

The situation in the sky was not optimistic, and the occasional fighter plane sent from Macedonia was also hunted and hunted by the German air wing, and often never returned, but became a joke.

The base camps of the two armies are more than 100 kilometers apart, and each side wants to insert a knife in the command organ of the other side, because the fighting has continued for many days, the suburbs of Sarajevo have become a no-man's land, the city and the outside of the city are scorched, many corpses have stinked because they are not buried in time, and the plague is quietly spreading.

During this period, the two sides competed openly and covertly, using infiltration and counter-infiltration to contest each other, but neither had effective reconnaissance measures, and neither could determine the location of the central organs of the other side.

In the face of this war, which did not need immediate results, the coalition forces only regarded it as a live-fire exercise, and the live target was the Greek army on the opposite side. The fighter squadron led by Lieutenant Colonel Ernst Udet of the German First Air Force is on the northern coast of the Mediterranean, more than 200 kilometers south of Sarajevo, and the primary radar developed by the Eric company is also being tested in actual combat.

In order to reduce noise, high-power generators are set up on the other side of the mountain, but the temporary base is very well hidden. The sound of the soldier on duty through the headset of the device can only serve as an early warning, but it cannot accurately judge the number, type, distance and direction of attack of enemy aircraft.

At about 9 o'clock in the morning, Lieutenant Colonel Ernst Udet received a report from the watchman that the enemy plane had been discovered, but he did not rush to order the fighters to take off, but asked the squadrons to prepare for battle and use the mountain as a cover to standby.

"There is no shadow of the enemy plane in sight yet, let them fly closer." Ernst Udet was calm, because this happened every day, and his experience taught him that it was more effective to let the Greek fighter plane appear and then direct the BF-10 to take off and attack the enemy from behind.

A few minutes later, two black dots appeared in the distant sky from north to south, and apparently, in order to avoid the coalition anti-aircraft artillery group, the Greek fighter plane flew very high.

The German temporary airbase had only one improvised runway, which was usually covered by tree branches, and all of them, including the fighters, were camouflaged and cleaned only when the fighters needed to take to the air. At this time, the base of the Ernst Udet brigade was facing east, so the Greek planes were well concealed in the dazzling sun.

The Newburgh 28 biplane fighter was a World War I aircraft that France originally aided Greece, because the French were not optimistic about this aircraft, so the production was not large, in the final analysis, the performance was not very good, and even the machine gun coordinator was not installed.

After being taught several times by the Luftwaffe BF-10, the Greek Air Force gradually learned to be obedient, and in addition to conducting battlefield reconnaissance and tactical strikes against enemy ground forces, it generally avoided frontal entanglements with German fighters as much as possible.

Ernst Oudt was not Germany's top ace pilot, shooting down 39 enemy planes in 11th place. But William Keitel was optimistic about his composure and was a commander with great potential.

The number one holder in the number of enemy aircraft shot down by Germany in air combat was Richthofen, with 86 aircraft killed, and no one has yet topped it, and this figure was not set by flying an advanced monoplane fighter such as the BF-10. Second place went to Oswald Polk with 82 flights very close to Richthofen. In third place went Max Inmaiman, who shot down 79 enemy aircraft. Since then, with the end of the First World War, their record has not been surpassed.

Udet could have shined in the ranks of the Federal Air Force, but he was overshadowed by these surviving ace pilots of air combat, and although his uninhibited personality was like an untamable horse, Commander William Keitel liked his unyielding blood, so he placed him in the elite of air combat to continue to polish it.

"Two Newburgh Type 28s are on cruise flights." Udet followed with a telescope. The two planes are about 1,000 meters apart from the ground, and it is difficult to distinguish the type of aircraft by looking at it with the naked eye. Greece is not yet in a position to produce the aircraft itself, and the existing stock is not large, and with one is one less.

The Newburgh biplane fighter was still very recognizable in the Balkan Peninsula at this time, because at present, the large enterprises that can produce fighters are developing German monoplane fighters, and only the Newburgh 28 is still the same. Udet cocked the walkie-talkie and gave an order to the pilots who were already preparing to take off: "01, 03 pay attention, immediately taxi into the air, bite the enemy plane." ”

The two BF-10 fighters of the first squadron 01 and 03 immediately taxied to the runway, and with the roar of the piercing engines, the two planes rushed into the clouds one after another.

Newburgh 28 soon realized that it had been followed, made a climbing feint in the air, then turned sideways and dived northeast to avoid it.

In Udet's eyes, the Newburgh 28 is not worth going out himself, even if he gets the record of shooting down these two backward fighters, he doesn't feel any glory, after all, the German army uses the BF-10, and bullying the Newburgh 28 is too pediatric. Udet is a veteran pilot who has been honed many times by Toth, with superb tactical literacy and some arrogance.

The two fighters 01 and 03 quickly made corresponding movements and continued to bite the two Newburgh 28 tightly. The four fighters roared in the sky, like four flying rocs, constantly fighting.

Udet watched the cat-and-mouse game with a telescope, and said to the attendant next to him with a smile: "This is a great opportunity for military training, and it can't be finished until it is absolutely necessary." ”

"01, 03 Please note, lower the flight altitude, continue to track the flight, and do not overtake." Udet has already seen this air battle as a peacetime training.

After responding in the air, the four fighters flew high and low, shuttling through the white clouds, like an overall formation.

Udet never gave the order to open fire, and the flight attitude of the two BF-10 fighters kept changing with the Newburgh-28 operation. If you persist like this, even if the BF-10 does not fire, there is a risk that the Newburgh-28 will collapse due to too much resistance, after all, this is only a body reinforced with steel cables.

In contrast, the Newburgh 28 did not climb fast and was much slower to evade, and since it was bitten by German fighters, it had not been able to find a way out of it, so it had to keep bombing oil, sometimes diving, sometimes returning.

At this time, the sun is already heating up, and the temperature in the cabin of Newburgh warms up quickly due to the interaction between the engine and the natural environment.