Adlertag

Adlertag ("Eagle Day") was the first day of Unternehmen Adlerangriff ("Operation Eagle Attack"), an important operation by Nazi Germany's Luftwaffe (air force). This operation happened during the Battle of Britain after Britain refused peace talks with Germany. The goal was to destroy the British Royal Air Force (RAF) to make way for a possible invasion of Britain.

On July 16, 1940, Hitler ordered preparations for invading Britain, called Operation Sea Lion. But before that could happen, the Luftwaffe needed to control the skies by destroying the RAF. This would prevent the RAF from attacking the invasion ships or protecting the Royal Navy.

Adlertag took place on August 13, 1940. The German planes attacked, causing damage on the ground. However, because of poor planning and communication, they could not weaken the RAF enough to control the air. As a result, Operation Sea Lion was never carried out because the Luftwaffe could not gain the needed control of the skies.

Background

Strategic overview

Main articles: German occupation of Luxembourg in World War II, Battle of the Netherlands, Battle of Belgium, and Battle of France

After World War II began with Germany’s invasion of Poland, Britain and France declared war on Germany. For nine months, there was little fighting along the Western Front. In May 1940, Germany launched a surprise attack through the Low Countries, leading to the rapid defeat of France. The British army managed to escape from Dunkirk, but Germany controlled much of Western Europe.

With France defeated, Germany turned its attention to Britain. Adolf Hitler hoped Britain would agree to peace, but Prime Minister Winston Churchill refused. Germany began planning an invasion called Operation Sealion. Before invading, Germany’s air force, the Luftwaffe, needed to weaken Britain’s Royal Air Force (RAF). This plan was called Operation Eagle Attack (Adlerangriff). If the Luftwaffe could defeat the RAF, Germany believed an invasion might not even be needed.

Background: early battles

The Luftwaffe had lost many planes in the battles for Poland, Norway, and France, so it needed time to rebuild before attacking the RAF. In July and August 1940, Germany focused on attacking British ships in the English Channel and bombing coastal airfields and radar stations. These attacks did little damage to Britain’s air defenses.

On August 12, Germany launched its first major attack on RAF airfields inland. Targets included Hawkinge, Lympne, Manston, and several radar stations. The attacks caused some damage, but the British quickly repaired everything and were ready to fight again the next day. German planners thought they were having more impact than they actually were, which would affect their next move. By this time, the Luftwaffe had rebuilt its forces and was ready to launch a full-scale attack on the RAF the following day, Adlertag.

Luftwaffe preparations

Intelligence

Wrong information was a big reason why Adlertag did not work well. The British were starting to learn more about German plans than the Germans wanted them to. They could read some German messages easily, which helped them know what was coming. This helped the British understand where German planes were and what they were planning.

The leader of German air intelligence made several big mistakes. He thought the British had far fewer airfields than they really did. He also guessed that Britain could only make a few fighter planes each month, but they were actually making many more. He did not talk about how quickly the British could fix their planes or how well they were organized. Most importantly, he did not even mention the British radar system, which helped the British know when German planes were coming. Because of these mistakes, the German plans did not target the most important British defenses.

Targets and order of battle

Main articles: Organization of the Luftwaffe (1933–1945), RAF Fighter Command Order of Battle 1940, and Luftwaffe Order of Battle August 1940

The following targets were chosen for attack on 13 August 1940:

RAF operational command

Main article: Dowding system § Description

The British defence during this time relied on a clever system to track and direct their aircraft. This system was created by Air Chief Marshal Sir Hugh Dowding and was called the Dowding System. It used a technology known as Radio Direction Finding, or RDF, which acted like an early radar. This helped the British spot enemy planes coming from far away.

When enemy planes were detected, information was sent to a special room at RAF Bentley Priory. Here, people, including members of the Women's Auxiliary Air Force, would move markers on a map to show where the enemy planes were headed. This helped leaders decide how to respond quickly and effectively.

Battle

On the morning of August 13, the weather was bad, and the German commander postponed the raids. However, one group of planes called KG 2 did not get the message and took off anyway. They flew toward an airfield in Eastchurch on the Isle of Sheppey. Although they were supposed to wait for escort planes, KG 2 continued alone. The British radar misjudged their direction, so the British fighters were not ready to stop them. KG 2 claimed they destroyed ten British planes on the ground, but in fact, no British fighters were lost. The airfield was damaged, but it was back in use by evening.

Later that day, more German planes attacked airfields and ports in southern Britain. Some attacks were called off, but others went ahead. The Germans faced British fighters, and several German planes were shot down. The attacks caused some damage but were not as successful as the Germans hoped.

In the afternoon, more attacks began. Planes bombed targets such as Boscombe Down and Worthy Down. Some groups changed their targets because of clouds or strong British fighter defenses. One group bombed Southampton by mistake, damaging warehouses and a cold storage plant.

Other German planes attacked airfields near Southend and Rochester. Some failed to find their targets and dropped bombs at random. One attack on RAF Detling caused casualties among the ground staff, but it did not affect the main British fighter defenses.

More raids hit places like Heathrow Airport and the Short Brothers factory at Rochester. The factory suffered damage, but British fighters intercepted the German planes and shot some down.

That night, German planes continued their attacks. One group targeted a Spitfire factory in Birmingham but caused only minor damage. Another group attacked a factory in Belfast, destroying five planes. Other raids hit cities across Britain, causing some damage but not much overall.

Aftermath

The German air force kept attacking airfields in southeastern England. They focused on many airfields near London, but some attacks missed important bases. The plan to weaken British air defenses did not work.

Both sides reported shooting down more enemy planes than actually happened. The British said they shot down many German planes, but the real number was lower. The German air force also claimed to have destroyed many British planes, but their numbers were much too high.

Even though the first major attack, called Adlertag, failed, the German air force kept attacking. They tried many different strategies but could not defeat the British air force. The British were able to keep replacing pilots and planes. Later, the Germans changed their strategy to bombing cities, known as the Blitz, but this also failed to achieve their goals. The Battle of Britain was an important victory for the British, allowing them to later help launch attacks against Germany during the war.

Main article: Confirmation and overclaiming of aerial victories