The Process Behind an RAF Nighttime Air Raid on Nazi Germany

By the end of World War Two, the British RAF had developed a well-practiced routine for air raids against the Third Reich.

RAF Lancasters on a nighttime raid photo from WikiCommons

For the first years of the war, the only way that Allied forces could reach Germany was by air. These raids, however, were limited both by the relatively short range and small payloads of the RAF’s available bombers and by British policy restricting air strikes to specific pinpoint military targets.

By late 1943, however, the situation had changed. The Avro Lancaster heavy bomber, capable of delivering seven tons of bombs to nearly all of Europe, became available, and the head of RAF’s Bomber Command, Sir Arthur “Bomber” Harris, had lobbied for an official British policy of “area bombing”, in which entire cities were to be the target. By 1944, there were some 700 military airfields in the UK, and the British RAF was using Lancasters to attack German cities almost nightly while the American AAF was using B-17s and B-24s to bomb the Nazis by day. This round-the-clock bombardment continued for the rest of the war, pounding all of Germany’s major cities to rubble.

RAF Lancaster photo from WikiCommons

A typical late-war RAF night-bombing mission actually began long before the bombers ever took off. Already in 1942 a list of target cities had been drawn up, which were to be systematically bombed. It was Bomber Command who decided which cities would be struck on each night.

Just prior to a planned raid, often that very morning, unarmed reconnaissance aircraft would dash over the targeted city to take fresh photos. These would then be examined by specialists to find any new enemy anti-aircraft positions or other defenses, and then used by planners to draw up orders for the mission. This would culminate in the designation of one or more APs, or “Aiming Points”—the spots at which the incoming bombers would drop their loads. Most often the AP was near a landmark that would show up prominently on the rather primitive radar screens of the day—a lake, a bend in a river, or a confluence where two rivers came together. The British H2S radar sets of the time worked best if they could focus on features that gave a high-contrast radar echo, such as water.

Since the RAF flew its missions at night, the bomber crews could not see each other, and, with as many as a thousand heavy bombers converging on one target in the dark, there was serious hazard of mid-air collisions. To prevent this, each squadron would be assigned a carefully-calculated flight path, at a speed, timing, and altitude which would put all of them over the target within a 20-30 minute span but keep them far enough from each other to avoid accidents. This also allowed the required fuel load to be calculated for each squadron, while the range and the nature of the target to be hit determined the bomb load which each Lancaster would deliver, whether incendiaries, high-explosives, or a mix of both. Some bombs would be fused to detonate on impact, while others would be delayed for hours or sometimes days, to cause as much disruption as possible. This part of the detailed planning fell to the Air Group Operations Officers.

Once this was done, specific orders, known as “Form B”, would be issued to each Squadron Commander in the Group, arriving early in the morning. These were first passed on to the ground crews and armorers so that the Lancasters could be loaded and fueled according to the specific instructions ordered. And, although the exact target was still secret and was presumably known only to the higher officers, the plane’s ordered loadout gave a pretty good indication of roughly where they were going—whether it was a short “milk run” over Occupied France or a much more dangerous long haul to Germany.

So, by the time the aircrews were briefed later that morning, they already had a pretty good guess where they were going. For most of them, they had already flown several bombing missions. Some crews, of course, were new and were making their first combat flight—they were replacing other crews who had just been shot down. In the RAF, a Lancaster crew’s tour of duty was 30 missions. About two-thirds, however, didn’t make it that far. On any given mission, a squadron of 18 Lancasters (plus 2 spares) could expect to lose 1 or 2 aircraft and their 7-man crews.

The briefing came in several stages. A large map on the wall was marked with a red ribbon which indicated the route the squadron would take to the target and back. A meteorologist gave information about the weather to be expected on the way out, over the target, and on the way back. Of particular importance were the predicted wind speeds and direction (vital for both navigation and bomb aiming) and cloud cover over the target. An intelligence officer then gave information about expected enemy resistance and the locations of AA guns and fighter bases. Finally, a Flying Control Officer passed on detailed instructions about the planned flight path, including the precise “Time of Takeoff” for each airplane. It was crucial that each Lancaster stick to its specified route and schedule, since this both guarded against collisions in the dark and insured that a concentrated strike over the target could overwhelm the enemy’s defenses.

RAF briefing photo from WikiCommons

The RAF had, by 1944, two electronic systems which helped navigate bombers to their targets. The first of these was codenamed “Gee”, which worked by comparing the radio signals from two fixed separate sources and calculating the difference in the time it took to reach the aircraft. Originally developed as a way to land aircraft at night, it was extended into a navigational beacon with a range of around 250 miles. The other system was codenamed “Oboe”. In this setup, a radio signal was sent out from a fixed station and immediately returned by a transponder in the bomber, and comparing the time difference between the signals allowed the plane’s position to be calculated.

The RAF began sending specialized aircraft equipped with Gee or Oboe, known as “Pathfinders” (often a Mosquito light bomber) ahead of the main bomber force to locate and mark the target. The Pathfinders would drop green route marker flares along the way and a circle of red flares known as “TIs” (“Target Indicators”) around the AP. The incoming bombers would then aim their own loads at the center of the TIs. Long missions such as Berlin, however, were outside of the range of the British Gee and Oboe, so the Pathfinders would then depend on their H2S radar sets to find the target and mark it.

The flight crews arrived at their Lancaster about an hour before their scheduled takeoff time, to go through a series of preflight inspections and checklists. By this time the plane would already have been fueled and armed. 

From the moment of engines start, the Lancaster crew operated in strict radio silence (though crew members could talk to each other via the aircraft’s intercom). Any radio transmission might be intercepted by the Germans and give away information about the size and composition of the bomber force. 

Accidents on takeoff were not uncommon. If a pilot strayed from the paved taxiway, he risked getting his wheels bogged in the mud and blocking the taxiway for everyone behind him. An engine failure on takeoff usually meant a fiery crash with seven tons of bombs and full gas tanks. About twelve percent of RAF casualties came from accidents.

After takeoff, it took about 40 minutes to reach cruising altitude of 20,000 feet. The flight to Germany could be as long as 3.5 hours. This was done in radio silence, and for much of it the Lancasters were also out of range of British radar, making it impossible for the home base to track them.

It was, of course, easy for the Nazi radars to track them. One countermeasure for this was “Window”, which consisted of thousands of thin strips of aluminum foil that floated in the air and reflected German radar waves, blotting out the signal. 

The biggest danger to the Lancasters were the Nazi night-fighters. Junkers Ju-88s, Focke-Wulf FW-190s, and Messerschmitt Bf-110s were equipped with airborne radar sets and modified gun mounts, enabling them to track and intercept the bombers in the dark. To try to fool them, the British bomber groups often took convoluted paths to their targets, hoping to throw the night-fighters off-track.

Ju-88 night fighter photo from WikiCommons

As the bombers got close to their target, though, the fighters would peel away, and the anti-aircraft fire (known as “flak”) would take over. This was also a dangerous time for the bombers. Most German cities were heavily defended, and during this portion of the bomb run the Lancasters had to fly a straight and steady course to insure bombing accuracy. It made them sitting ducks for the flak gunners. The bombardier sat in the nose of the plane and shouted directions to the pilot: “Right. Left, left. Steaaaady.”

Once the bombs were gone, the Lancaster was suddenly seven tons lighter, which meant it could fly higher and faster as it turned for the most direct route home. But the crew was not out of danger yet. The night-fighters were still waiting for a chance to strike again at the bombers as they once again ran the gauntlet. Planes that had been damaged by flak and who had fallen behind, often trailing flames, were easy targets for the fighters.

When the squadrons finally reached their home fields, they were not yet safe. Landing in the dark, especially if the plane was damaged, presented its own difficulties and accidents, and on long missions the bombers would often be required to land in thick morning fog. Some of them would be forced to land at another airfield. And some of them would not come back at all—they had been shot down over Germany, had crashed in France, or had been forced to ditch somewhere in the North Sea.

Upon safely reaching the ground, the crews, who had been crammed into their stations for as long as seven hours, were given a cup of tea (fortified with a healthy dose of rum) and led to the debriefing huts. Here they were asked to describe everything that had happened, in detail: how well the equipment worked, any mechanical troubles with the plane, the tactics used by the German fighters … any information that might be in any way useful. 

Shot-up Lancaster photo from WikiCommons

It was only after the debriefing that the exhausted airmen were finally able to curl up in their bunks and sleep.

In a few hours they would be woken for another briefing, and another mission.

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