B17 BOMBING TUTORIAL
Part One: The Norden 

The B17 carrying bombs may be compared with a gun platform. But it is an unstable platform that never stays in one place,  moving rapidly in 3 dimensions and about 3 axis.

During the bomb's trip to earth 3 forces act upon it.

While hanging in its rack it is the forward motion of the plane, and when released, it has that same forward speed. In a vacuum it would continue to move at the same speed in the same direction as the B17. It would in fact be directly under the plane at the moment of impact.

Gravity the 2nd force, affects the bomb from the moment of release. Its effect is easily calculated in terms of speed or distance fallen at any instant after release. Gravity works straight down, the bomb's initial velocity works horizontally. By combining the two we get the fundamental problem of a bombsight: How far DOWN and how far FORWARD will the bomb be after a certain amount of TIME?

The 3rd force is air resistance acting to resist the other two forces. Air resistance acts more on horizontal motion than gravity: a bomb falls in an ever steepening path. If the bombs are made consistently, it is only necessary to time the fall from all altitudes in tests.   Example: a B17 drops a bomb at 200mph. The actual time of fall from 1000' is 8 secs. But in that time it loses enough horizontal velocity to make it travel 67' short of 2,350' it would have gone at 200mph. This lag is called TRAIL. This lag was measured for various speeds and altitudes to create tables for bombardiers.

But there are other factors involved. One is wind speed. Suppose the wind is a constant 30mph on the nose. The B17 going 200 mph will move 2,350' through the air in that 8 seconds. But the air block will move 350' in the opposite direction. Instead of traveling 2,350' over the ground, it will travel only 2,000, and the bomb will lag that 67' further, for a distance of only 1,933'. This horizontal distance moved by the bomb is called RANGE. If the wind is on the tail, the effect is opposite: the RANGE now being 2,633' while the B17 travels 2,700' over the ground. Data is therefor based on true airspeed and time of fall, while the Norden must work on groundspeed. This is the basic function of a bombsight: a ground speed meter.

But there are still more variations.

Consider a 30mph wind blowing across the flightpath. The B17 must "crab" by heading along the airpath, rather than pointing directly at the target. (Among sailors it would be said to be following the "apparent wind"). It makes good that path with respect to the air, and the bomb still lags the same amount. However, during that time the block of air has moved to the right over the ground, and here is the problem: the bomb does not fall along the flightpath of the plane. At no time after release, in fact, is it along that line. Yet this "cross-trail" can be determined as a function of trail & drift angle. In the Norden this factor is compensated automatically as a result of the other entered data. The wind is determined from the difference between airspeed and ground covered, as well as from observations of trees on the edges of woods, and from waves at bends of rivers.

The last major factor is that the B17 itself is not stable. It is free to move in 3 directions & rotate about 3 axis. Changes in the reference of 3-4 degrees is normal, and 10-15 not unusual. One degree equals apx 17 mils. 1 mil covers 25' on the ground when sighting from 25,000'. An oscillation of 3 degrees then would cause an error of 1,275'. A 3 degree error in direction maintained for 40 secs produces an error of 750' at the release point. And 25,000' below, the bomb impacts, after about 42 seconds, 1,500 to the side of the target. Thus the reason to design in stability over maneuverability. Innovations in electric rotors for gyroscopes also minimized this problem.

To know the moment to release the bombs, the Norden must know: the length of time to fall from the altitude; the horizontal speed with respect to the target, and then multiply that speed by the time of fall, resulting in the horizontal distance. The trail (lag) is subtracted from that, and the Norden produces a Range Angle: the angle formed between the line of sight to target and a vertical line from the B17 to the ground. This is the Norden: an automatic speed and distance calculator which interprets its findings in the form of an angle.

What does this have to do with the Norden in Swotl? Not much, but it's useful background info to appreciate just how much the Bombadier is doing while we shoot the guns & swear at the Jerry's.

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B17 BOMBING TUTORIAL
Part two: The Swotl Norden 

After flying many, many missions to research and practice targeting, I can now share with you the ability to take out even small builings with one bomb from altitudes up to 29,000 ft!  Here's how.

The Norden Bombsight as modeled in Swotl is very accurate. Unlike the problems of the real life Bombadiers, you do not have to calculate speed over the ground or wind drift. The bombsight works by using a mirror to reflect the view from forward of the flight path, verticaly into the sighting mechanism. This angle of view (AV) is expressed in degrees. 90 degrees would be looking straight down, while 15 degrees is be well forward of the current position. From this we can learn the following:

1: The lower the degree, the greater the AV, the longer the countdown time, and the greater the induced error in targeting. 

2: The higher the degree, the closer the target is, the shorter the countdown time, and the lower the induced error.

Most errors in trying to learn bombing are caused by the variable use of the magnification factor. The reason has to do with the change in the area of view in the sight. For instance, you fly a mission and your bombs were late, so you release next time with one of the concentric rings as your trigger point. But what magnification are you using? If you are setting the timer when the smllest ring passes the target, that position will be different if you change the magnification. At 10x the ring may be 100 yds away from the point under the center pip, while at 25x it may be only 10'. This tells us:

As you zoom in & out, only the point under the center pip remains in the same position.

Consistency, and always using the center pip as your targeting point is the key. If your bombs are early, or late, use the pip as your reference when you drop before, on, or after the target. Here is what I consistently score with:

Altitude  Speed  Engine  Mag  Angle  Time     
23,000    160     53%    15x   50    :42   
23,000    160     53%    15x   60    :17   
25,000    160     53%    15x   50    :47    
25,000    160     53%    15x   60    :20   
27,000    155     52%    20x   50    :52   
27,000    155     52%    20x   60    :23   
29,000    155     52%    25x   50    :60   
29,000    155     52%    25x   60    :28   

I hit "s" for the timer as soon as the pip touches the leading edge of the target. If taking out a small builing with one bomb, I delay an instant, until the pip is ON the wall of the leading edge. It's THAT precise. 

On the last test, 29K' @ 25x/60 degrees, the small building FILLED the sight. I had ample time to set the timer when the Pip was in the middle of the panel angling from the wall to  roof. And that's exactly where the single bomb hit.

Rules: Always use the pip as your reference.
       Use the highest angle possible.
       If your time is over :60, come back and set it again.
       Be conscious of the magnification power you're using.

If the fighting is thick and I get a moment free, I'll set the timer, even if it's long. That way, if I don't get back, I'll still drop. If I get free, then I'll reset for greater acurracy. As you gain experience, you may well adjust the angle to give you a shorter countdown. This will be easy, just watch the mag factor!


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B17 BOMBER TUTORIAL
Part Three: Targets and Tactics

There are four distinct phases of a bomber mission: the Approach to the Initial Point; the Bomb Run; the Escape; the Flight Home. But the mission centers around this: The sole purpose of a bomber is to drop it's bombs on the target.
Planning then, begins with the bomb run. Your job is to destroy as many buildings at the target as possible. How will you align your flight group? How many planes will you use? From what angle will you approach?

To begin, consider: the layout of the target; number of available bombers; and expected opposition.   This table lists the target types, number & size of buildings, and the orientation that lines up the most buildings - under the flight path of 1 bomber only. I draw here partly from CGW 5/92.

  TARGET            LGE MED SM  OTHER   ORIENTATION
Ball Bearing Fact.   2   2               N-S (2L 1M) 
Research Site        3   1   1           W-E (3L)
Aircraft Factory     2   1   5           W-E (3S 2L)
Oil Refinery         1   1      8 tanks  W-E (3T 1L)
A/C Engine Fact.     3   3               N-S (3M)
Munitions Factory    2   1   2           NwSe (2L)
Rail Center          4   4   1           NwSe (2L1M)
Airfield                     1 2 hangars W-E (2H)
                               4 towers
Airfield                     3 2 hangars W-E (2H)
                               4 towers  N-S (3S)
V-1 Site             3   3   1   1 ramp  NwSe (1M2S)
V-2 Site             1   2   3   1 pad   NwSe (1M2S)

One B17 can take out two large bldgs of a munitions factory, IF the bombs are properly spaced. Four B17's can destroy several refinery bldgs  - IF all four survive to drop their bombs.  V1 & V2 sites and the line of hangars at airfields, are relatively easy targets and the combat box formation is ideal. There is good coverage to the sides of the flight leader's bombs. But the buildings & tanks at a refinery can sustain greater damage from the wider "spread" of bombs a line abreast formation. The game, unfortunately, does not give us the ability to drop from a combat box to line abreast and then back. But line abreast is a relatively defensible formation. It provides greater protection from less than perfect rocket attacks. And the major guns, top, belly, nose, tail, all have clear fields of fire. The angle from which the B17's are in a line, is directly from the side - the most difficult of deflection shots. The cpu pilots, however, are not very good at closing up until the flight home. Generally, I find the Combat Box formation the best all around formation.


Now that you have determined the optimum direction of the bomb run for best bomb coverage, consider the immediate threat - ground fire. Coverage is usually uneven around a target. Flack guns have a 3 mile range. Often, it is less dangerous to fly directly over a flack battery, than to fly for a longer period in the range of several. If you must pass near a larger group, it is better to approach so that they are on the "downwind side" of the drop point. They won't affect you until after you've set the Norden, and after dropping, you can rapidly make changes in course and altitude to throw them off.


To Lead or Follow?

If you are the Group Leader you can alter your course to line your B17 up on the most bldgs and the others will add to the spread. If you are not the Leader you can still alter your course - but the others will not follow unless the Leader is shot down - in which case the others will quickly come to your course. But if this happens just before the drop point, they may not drop with you! 

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B17 BOMBING TUTORIAL
Part Four: Flying the Mission

Upon entering the cockpit turn on Autopilot, note course, altitude, engine %. Look closely at the airspeed dial. Be very specific about where the dial is. If you need to, Pause the game while you do this. If you take evasive action, or engine damage you want to be able to get back to the proper speed & course. 
Develop a routine for cycling thru the guns and arming them. A look at the map will give you the precise airspeed and alert you to any enemy that are out of visual range. 

As soon as possible, go to the bombardier station and elevate the bombsite to view the target, or horizon if there is a turn at the IP. 

Turn the camera on and then hit "v" for the Viewing Room. Here, click on the disk cache to increase the length of film. I like 200k. Exit back to the game. It's possible to do all this in under :30. 

The Threats to your B17 in descending order:
Rockets
Fighters
Flack

The cpu pilots will never take evasive action! They do not close ranks very often. Rockets are the greatest threat because they can be fired from outside gun range, travel very fast, and can damage w/o impact as a result of a close proximity burst. Thus, Cpu pilots are sitting ducks. It does not matter if their score is 25,000 or merely 25. Survival depends only on the skill of the attacker. You, however, can take evasive action. Rocket attacks usually come from the front or rear quadrants, rarely as a deflection. Closely watch A/C approaching from those angles! If you detect a smoke trail, watch for any movement to the sides or vertical. The more they change, the less likely it will hit you. Rocket trails with little motion are coming directly at you - prompt action is required! Jump to pilot, auto off, steep dive with possible turn. As soon as they pass, pull up swiftly and resume course. This is your only chance. 


Debriefing

By using the camera it is possible to carefully evaluate your bombing (and your wingmen's), review the attacks made on you, and do this from different views. This is a valuable tool. 

To master bombing, I urge you to play in the Campaign Battles. Most missions  are not as hard as Historical Missions.  And because you can select a different crew for each mission, there is not the same loss as in a Tour of Duty. So you screwed up and Shoo Fly is blown to pieces, that's OK because Sweet-16 can be your next ride.  The steady progression of a Campaign lends a sense of ongoing development that keeps the spirit up. You can experiment with plotting missions and formations. You can even play a round as a fighter, and try to protect the cpu pilots and see how they carry out your mission. 

Have fun! 
                      BOMB'S AWAY!!!!!!!!!!!!!!!

  

