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VMF-215 BOMBER SQUADRON TRAINING

DIVE BOMBING - BRIEF OVERVIEW

Contents
     Dive Bombing - Historical Notes 
     Dive Bombing - The Art

Dive Bombing – Historical Notes
           
The theoretical basis for dive-bombing is simple enough, that it would come to different minds in different places and at different times. It would
probably be unjustified to look for the "inventor" of dive-bombing.

In normal (horizontal) bombing the released bomb has a horizontal, forward speed vector given to it by the movement of the aircraft. To this a
vertical acceleration is added, caused by the pull of gravity, which causes to bomb to fall. The combination of the two, results in a parabolic
curve, which is distorted by the drag of the bomb and the wind. The basic idea of dive-bombing is to make the speed vector of the aircraft
coincide with the direction of gravity -- vertical -- so that the trajectory of the bomb becomes a straight line instead of a complicated curve. This
greatly reduces the problems of bomb aiming. Because the bomb is usually released from lower altitude and at higher speeds, the effects of the
wind are also minimized.

There are of course also disadvantages. A vertical or near-vertical dive results in a rapid build-up of speed, and airbrakes are needed to reduce
the terminal dive velocity of the aircraft to acceptable limits. At the end of the dive, after the release of bombs, a sharp pullout is necessary to
keep the aircraft in the air, and this puts considerable stress on the aircraft. These requirements usually meant that dive-bombers had to be
heavy, robust aircraft, with an unimpressive performance in level flight. Dive-bombing also required highly specialized, intensively trained crews.
These pilots not only had the technical problems of judging the diving angle correctly -- the natural tendency is to overestimate it -- aiming their
bombs correctly, dropping them and then pulling out at the correct time. They also had to resist the mental and physical stress of a fast dive and
a sharp pull-out maneuver.

The technique was first used during Word War I. The first officially acknowledged dive-bombing attack seems to have been made by Lieutenant
Harry Brown of the RFC (Royal Flying Corps) who sank a munitions barge in 1917. After the end of the war the RAF (Royal Air Force) conducted
research and experiments, but finally decided that the method was too dangerous and halted its development. Instead, the British chose to
concentrate their efforts on the creation of a strategic bombardment force. The FAA (Fleet Air Arm) kept the idea alive, but the development on
its aircraft was seriously hampered by the RAF control over all aircraft, including shipboard aircraft.

The development of dive-bombing continued in the USA. The USMC (US Marine Corps) practiced dive-bombing, although seldom at angles of
more than 45 degrees, during operations in Haiti in 1919. A more refined form of the technique, influenced strongly by aviators who had flown in
Europe during W.W.I, was used during the US intervention in Nicaragua in 1927. During these years, the USMC pilots also included spectacular
dive-bombing demonstrations in their air show routines. The USN (US Navy) adopted dive-bombing as doctrine, not to provide ground units with
tactical air support (as had been the goal of the USMC) but as an effective method to hit enemy ships - relatively small, moving targets. The
aircraft used during these years were developments of the Curtiss Hawk family of fighter biplanes, the F6C and BF2C. The name of `Helldiver'
was attached to these aircraft, although this would not become officially the name of an American aircraft until the Curtiss SB2C was introduced,
during W.W.II.

In Germany, forbidden by the treaty of Versailles to develop military aircraft (a regulation which was often infringed upon, with the occasional help
of the Russia, Japan, Sweden, the USA and other countries), the military leadership had to concentrate more on the theory of their application.
Theorists developed the concept of a new style of mobile warfare, fought by Panzer divisions which combined tanks with motorized infantry and
artillery, and intensively supported by attack aircraft. After Hitler came to power in 1933, work began to convert the theoretical concept into a real
force. Ernst Udet, the head of the aircraft development program of the Reichsluftwaffe, was very impressed with the demonstrations he saw in
the USA in 1933. (Not because the concept of dive-bombing was new to Udet, for the development of German dive-bombers was already
underway.) After he had flown the Curtiss Hawk, he bought two, which he demonstrated in Germany. This helped to advance the case of the
dive-bomber in Germany.

Dive Bombing – The Art

In the war in the Pacific, dive-bombing was a deadly art that required as much raw nerve as it did sheer flying ability. For attacking moving
targets, such as ships, it was much more accurate than high-level bombing, but it was also much riskier.

Flying at an altitude as high as 12,000 feet to avoid enemy detection, a dive-bomber pilot would pick out a target. Then, he would open his dive
flaps so that his diving speed would be about 250 MPH, and push the stick forward so that his aircraft would plunge toward the target at a 70 to
75 degree angle. The direction of the dive determined the trajectory of the bomb so the pilot kept the nose of the dive-bomber right on the target,
preferably the stern of the ship.
  
For a harrowing 35 to 40 seconds, the aircraft would dive while anti-aircraft fire burst around it. The pilot would keep his eye on his bomb-sight
telescope and move the ailerons to adjust for wind or any movement of the target. Frequently, pilots would zig-zag during the first part of the dive
to make the plane a more difficult target for enemy fighters and antiaircraft fire. At around 2,000 to 1,500 feet, the pilot would release the bomb.
Since a bomb takes less than three seconds to hit a target from 1,000 feet, the aircraft would be in danger of being blown up by its own bomb if
it dived any lower.
  
The pilot would then quickly pull the nose up, subjecting himself to a large amount of centrifugal force - usually from 5 to 6 Gs. If he was lucky and
anti-aircraft fire or a fighter cover didn't get him, he would then hear the unmistakable sound of his bomb exploding on the target.

Source Info

Dive Bombing - Historical Notes

Dive Bombing - The Art

ESCORT AND INTERCEPTOR TACTICS - Neil Mouneimne (published by Micropose)

One of the most aggravating tasks for a pilot is babysitting duty. As a fighter pilot, it's your natural instinct to pursue the enemy and shoot him down. The problem is that you have to fly as if an invisible tether connects you to the bomber formation at all times. Dogfighting is a luxury that you can rarely afford. If you start to mix it up with another fighter, you'll drift away and below the bombers. Eventually you'll be so far below and away from the formation that you are effectively out of the game for quite some time. Even if both sides are evenly matched, leaving the bombers takes the risk that a second squadron of interceptors could appear on the scene and stomp on your charges while you putter away with an overheated engine down below, helplessly trying to get back into the battle.

Babysitting your big friends
Your strategy in this situation depends a lot on what you're trying to accomplish and your own strengths and weaknesses. When you reach the enemy fighter cover, there will be at most one head-on or side pass, then the interceptors will end up in a relatively dispersed sphere about a mile behind the bombers, frequently followed by your fellow pilots. Out of that morass back there fighters will emerge in ones and twos to make rear attacks against the bombers. Essentially you have to decide between taking some kind of trail position or an "orbiting" one. 
To get into the trail position, fly about three to four thousand feet behind the bombers, cruising at their speed or slightly faster. Use the cockpit views aggressively to spot interceptors working their way past you. As each one sails by, you should have a nice stable shot opportunity. Fly into the target with just a little deflection unless you're really close. By doing this, you are putting the target in profile, exposing more of the interceptor's surface area to your guns. Keep your wingman close by where he can cover your tail if someone tries to latch on. Inevitably, you'll creep closer and closer to the bomber formation and eventually reach the point where you run the risk of being hit by nervous tailgunners trying to fend off the interceptors. At this point, you should climb up and turn about 90 degrees off to one side, increase your separation for a bit, then turn back into the battle and start the process all over again. Trailing gives you the greatest chance to really cover the bombers, but it has three drawbacks. You're vulnerable to fighters that may attack you instead. Some fighters will make fast attack runs and thus be extremely difficult to catch. Finally, you run a real risk of having stray rounds hit your own bombers. The key to the whole thing is to limit the exposure time where the bombers are within the weapons parameters of the interceptors.
An orbiting escort means that you fly at a normal cruising speed, tracing a wide zigzag pattern behind the bombers' flight path. The idea is to keep station a constant distance behind the bombers without slowing down. Each time you pass across the formation's flight path, look over your shoulder in the direction of the bombers. Any fighters visible over the lip of your seat or rear bulkhead are probably preparing to make an attack run. If you've maintained a sensible heading and rear separation, then you should be in a good position to turn back into the fray to make your attack. If safety is critical and you are handy with deflection shooting, use a slash attack. If you need a better shot, fly to a point behind your quarry, pull high at a distance of about 3000 feet out to trade speed for altitude, then roll over to face him and pull hard. If you time it right, the target should be spread-eagled in your sights, and it should take little effort to score a kill. Watch out for Bf 110s or other heavy fighters that have tailgunners, though. 
Some important tricks. If you just can't get the right lineup and range for a good shot at an interceptor about to strike, switch your weapons to your minimum setting (usually half your machine guns) and fire a burst or two right over the top of the enemy's canopy. If you get close enough, they'll lose their nerve and break off the attack at a cost of a few bullets. Remember that whether you win or lose a mission depends on how many bombers reach the target, so don't worry about shooting down every single interceptor. Just buy the bombers enough time to make their run, then let them fend for themselves while you get back to regular dogfighting. Now if the bombers you're escorting are less vulnerable than average, you can afford the luxury of picking your shots more carefully and even flying much further from the formation to go after interceptors more aggressively. 
How to hack away at the box
Bomber formations—particularly heavy bombers—are tough. There's no question about it. If you just go barreling into a fight with them, you'll find yourself in a smoking hole in the ground nearly every time. The trick to taking on bombers is to exploit your advantages. While you can't waste a lot of time on the defensive, your speed gives you the luxury of picking when and how to engage, while your guns are far more powerful and accurate than any single defensive gun mount. Don't just automatically tell your flight(s) to attack—pick the right time first! Maneuver the flight or squadron into a good position and only then give the order to engage. While the manual recommends attacking from the front, don't bother. Instead, position your flight behind and above the bombers first. You'll find that your mates are much more effective if you set them up carefully before unleashing them.

As with escort missions, interception missions make you face the decision about whether to take part in slashing or trailing attacks. Well-done slashing attacks make it almost impossible for escort fighters to effectively go after you, but they require good accuracy and a tremendous amount of self-discipline. Trailing attacks are much easier, guaranteed to allow you to rack up more kills, but you are extremely vulnerable to escort fighters. 
To pull off a slashing attack, position yourself a couple thousand feet above the bombers and a little under a mile off to one side. As you dive in, pick a target, predict its fight patch, and put your nose a bit ahead while keeping the target in sight. Once the timing looks right, fire a burst, adjust your aim if necessary, and fire again. The problem is that it's really tempting to keep up the attack until you see the target go down in flames or at least lose an engine. That's a luxury you can't afford. Even if you miss completely, you have to break off the attack around 1500 feet away and take up station at the same altitude, but the opposite side of the formation from where you started. This method of attack isn't the safest possible attack, but it's the best compromise as far as avoiding escorts and still giving yourself plenty of good shot opportunities. 
Let's say that you've tried slashing again and again, but either it's not lethal enough or you can't resist the temptation to press home the attack. That's understandable. Time to switch to a trailing attack. To pull this off, you'll need to keep the escorts off of your back. If you're squadron leader, commit half of the fighters under your command to engage the escorts. If you're just a peon, then keep your wingman close like you would in a trailing escort mission. Your attack begins 3000 feet away. Line up on the bomber at the edge of the rearmost formation—this bomber is generally the safest to attack. However, if you approach a little low and the formations are tight, you might see two or three bombers forming one continuous target in your gunsights. If that grouping is part of the same formation, go for it. Don't fire yet, but make sure that you're as neatly lined up as possible and make sure to reduce your closure rate as you approach 2000 feet.
There are three easy magic numbers to remember—2000 feet,1500 feet, and 1000 feet (or 600m, 450m, and 300m). At 2000 feet, you are close enough to score easy hits, but far enough away that the gunners are basically ineffective. Hold formation right here, adjust your aim a little bit to compensate for bullet drop, and take one short burst after another. It's tempting to really lean into the guns, but long bursts only cause jams and waste ammo—it's not worth it. Now if the formation you're trailing is flying really slow, it may be necessary to drop flaps to keep your nose on the target or you'll have to put up with the fact that you'll continually be creeping forward. As you creep to 1500 feet, you're in the heart of your effective guns envelope, although you'll certainly take some hits over time. At 1000 feet, your effectiveness goes up a little, but you're just making yourself an easy target. At this point, you should dive away, but turn at first so that the wings present a knife-edge profile to the gunners, thus presenting a smaller target area.

One last point. Remember to mask your cockpit from gunfire whenever possible! You have a little protection around most every side of the plane, but if you present your glass cockpit to a bunch of angry ball turret gunners at close range, they'll shred your skull for sure.

NOTES from Capt. Djevel

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