So there are plenty of entertainment media derived narratives and portrayals of WWII bombing raids. I combed through the previous questions and while some answered small parts, I'm looking for a more comprehensive overview.
The best way for me to communicate my inquiry would be to explain my understanding of a typical raid, and then have the inconsistencies and errors highlighted and pointed out, I hope that's alright.
To my understanding:
-Allied planners would gather intelligence about targets of importance from numerous sources, including reports from ground forces, intelligence agents, etc.
-A plan would be drawn up, including primary and secondary targets, and orders dispatched to multiple units, at multiple air bases.
-On the given day, weather reports over the targets would be gathered via intelligence networks seizing local reports.
-Multiple units embark at different times, bombers and escorts.
-These units would meet at predesignated rallying points.
-Several planes would be designated bomb leaders they would be responsible for navigating, and other planes in their unit would fly in formation.
-From the other side, air partols or radar or even ground forces, would detect incoming allied aircraft and report locations, heading and speed as best they could, or intelligence would get a hold of allied plans.
-Military intel would determine possible targets and send out an alert, anti aircraft crews would be put on alert, and fighter units dispatched from multiple bases.
-Units would break at given points to engage separate targets, sometimes in multiple cities.
-Enemy fixed wing planes would attack bomber formations head on to limit the amount of fire taken (I don't know about British aircraft, but American forces had more rear firing guns than forward, until the B-17G) They would then attempt to strip off the escorts with scouts and while drawn away other fighter units would dive from above at high speed making multiple passes at the bombers.
-The axis fighters would disengage before ground fire would be encountered.
-Bombers would enter the flak field, escorts would drop back to avoid casualties.
-Bomber pilots switch control of the aircraft to bombardiers they fly straight and level until bomb lead had drawn a bead on the target, bomb lead releases payload at given mark. Other bombers release their payloads, and set course for their landing destination. Fighters rejoin the group and escort to given point over friendly territory.
I guess my questions from start to finish would be:
-How were strategic targets determined?
-How were orders distributed?
-How were rallying point determined?
-Is the concept of bomb leaders accurate, or would all planes navigate individually? Was there doctrine for other planes/crews to be designated to take over if the lead bomber were disabled, or would this have been improvised?
-How much warning in terms of time could be expected from time of detection of a raid and the actual units being in range of ground anti-air units?
-Would ground anti-air crews be on alert at all times in locations with high value targets, or would they be called upon by incident?
-How accurate is it to state that enemy fighters would disengage before their friendly ground fire was encountered
-How accurate is it to state that bombers did not take evasive action once bombardiers were in control, and if this was a doctrine, how strictly was is obeyed?
-Was it typical for planners to have units land from where they took off, or was it common to plan for units to land at airfields other than those they took off from to be repaired/refueled and then have them return to where they were stationed?
-At what point would fighter escorts break from the group (presuming the raid occurred after the incorporation of long range escorts).
-How typical was it for a raid to target multiple cities?
-How typical was it for a raid to target a single city?
I understand that the topic is nuanced and a bit esoteric, and that due to differences in doctrine in British, American, German and Italian militaries, as well as the varied aircraft used, that generalizations won't apply to every raid.
As a final question, related to that, would it be fair to state that due to these inconsistencies and the varied targets attacked that each raid was completely unique with no two being truly comparable?
My apologies if my inquiries are exhaustive, I was really hoping to have a comprehensive overview of the topic.
Let me know if I've violated any rules, I don't think that I did, but I'm happy to make changes necessary to make this post compliant.
Your overall understanding is fairly accurate. One little detail I would add in is about the escorts, namely that they would be responsible for different legs of the mission. In other words, FG 1 would escort the bombers from the coast to waypoint A and then break off to go home, strafing targets of opportunity along the way (during the latter half of the war, anyway); FG 2 would escort from waypoint A to waypoint B. You get the idea. The purpose of this was to make sure that the bombers always had fresh escorts with them. If a dogfight broke out before they reached waypoint A, many of the escorts would be low on ammo or out altogehter. Then what good are they if they don't have any ammo? Additionally, the fighters would fly a zig-zag pattern above the bomber stream usually. This would allow them to 1) maintain an altitude advantage over incoming fighters; 2) maintain their speed (those movie clips you see where the fighters are tucked into formation right next to the bombers are bullshit). But this zig-zag pattern also means that for every mile the bomber stream flies, the fighters are flying 2 or 3 miles. So they need rotate FGs in and out for fuel concerns as well.
As for your questions:
-Strategic targets were determined largely on a big picture to small picture basis. What do we have to do to win the war? What's the most important aspect of the German war machine? For a while, there wasn't a single unified vision or goal. What I mean is, when contrasted with the single mission goal of destroying the Luftwaffe in the runup to D-Day, the bombing campaign didn't really have a single overall objective. They had a bunch of objectives. There are several reasons for this, but the overall reasons is that their force size wasn't big enough to be a war winning machine, so they could only act as a sort of supplementary force to support existing objectives, they wouldn't have their own war-winning objectives by themselves.
But by D-Day, they had the resources to really be a force by themselves. So their overall objective was to destroy the Luftwaffe at any and all costs. When they decided on this single objective, their focus shifted from a smorgasbord of target types to singling out aircraft factories, airfields, and oil refineries. It certainly helped that they had Mustangs by this point that could go deep into Germany with them. But they basically gave the Luftwaffe the choice, fight and die in the air, or die on the ground without putting up a fight. So the Luftwaffe fought and died in the air.
After D-Day, with the overall destruction of the Luftwaffe, targets were determined by more immediate tactical concerns. They would take out marshaling yards that could send troops and equipment to the front lines; they would take out the factories that could make the equipment in the first place, etc.
-I'm not sure entirely what you're asking regarding the distribution of orders.
-Rally points were generally landmarks that were easily visible from the air and could very easily be found with minimal navigation.
-Bomb leaders were a very real thing. They did the overall navigation for the group, as the entire group was following the lead plane. The individual navigators in the other planes were also navigating, but it was more for their own benefit in case something happened to the leader or to them. Each group and formation had their own orders and hierarchy as to who would take over in case a lead plane was lost.
-The Germans had a fairly sophisticated radar system and could detect the bomber formation while they were still over the channel. Different targets meant different routes, so this is sort of a mission-by-mission type of scenario, but the Germans were certainly plotting every piece of information they could and alerting every individual they could at every turn. They would also be trying to anticipate potential targets the bomber stream might be heading towards, so if a target was deep in Germany, its possible those units could have had several hours to ready themselves.
-The Germans would have units on call at all times to man their flak guns. They wouldn't necessarily be sitting next to their guns 24/7, but they would have guys ready at a moment's notice to go there if needed.
-It's very accurate that the Germans coordinated their flak and fighters. The fighters would engage the bombers to and from the target. It was during these legs of the mission that the bombers could change course and altitude and make the flak gunner's aim useless.
But when the bombers reached the initial point (IP) and started their bomb run, they would have to fly straight and level and at a steady speed. This usually lasted around 10 minutes (give or take), and it gave the bombardier an opportunity to find the target and dial in the bombsight corrections. So while the bombers were straight and level and steady, the flak would open up. The flak guns had roughly 10 minutes where they knew exactly where the bombers would be and where to aim. It was during this time that the fighters would break off. They might head home or they might regroup and prepare to launch new attacks once the bombers were taking evasive actions after the bomb run.
-This was pretty much an absolute. The bomber had to be flying at constant settings on the bomb run so the bombardier could dial in the necessary corrections in to the bombsight to account for crosswinds, speed changes, etc. A bomb dropped with just slightly off measurements could have that bomb landing literally miles away from the target. Their whole reason for existing was to put the bombs on the target, so there was no deviation. They were totally committed on the bomb run.
-The escorts usually used the IP as the point when they would stay off to the side of the bomber stream. They returned once the flak died down, whenever that was. Remember, flak and fighters were usually mutually exclusive. So as long as there is flak there's very likely no fighters to worry about.
-This depends on what you mean by "raid." Were multiple cities hit on one day? Almost always. Remember that the Americans alone had, just in England, the 8th and 9th Air Forces. They had B-17s, B-24s, B-25s, B-26s, and A-20s. They were hitting targets all over the continent almost every chance they had.
If, however, you mean did one mission target multiple cities (as in, did one formation of planes go to multiples cities on one mission), then the answer is no. At least, I can't think of any instances of this happening to my knowledge. Mission were there and back. They weren't saving 3 bombs for city A and 4 bombs for city B. Every bit of ordnance was destined for city A. Unless it was clouded over and they couldn't find it. Then they would all go after city B. City C was a third option if city B didn't work out. Usually, after city C (or sometimes in lieu of it), the let the crews pick a target of opportunity based on what they saw on that mission.
I hope I answered your questions. If you have more or want clarification, go ahead and ask. I love this stuff.
Here's a video you might want to watch that should explain some stuff for you.
(My qualification for this answer: 12 years as a B-17 flight engineer, dozens of WWII vets interviewed by me, and three full bookcases of topical books read over a span of roughly 25 years studying this topic.)