A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy and limit the exposure to and effectiveness of anti-aircraft fire. This type of aircraft was most heavily used before and during World War II; its use fell into decline shortly afterwards.
Dive bombers were widely used to attack high value targets such as ships and bridges. This also had the advantage of attacking ships at a weak spot; armour was the heaviest near the waterline and thin or nonexistent on the deck. In addition, dive bombing allowed relatively small airplanes carrying limited bombload to inflict disproportionately heavy damage.
On the minus side, optimizing an airplane for near-vertical dives came at the expense of performance. In addition, a dive bomber was extremely vulnerable to ground fire as it dived towards its target. Dive brakes were employed on many designs. These created drag which slowed the aircraft somewhat in order to increase accuracy. These were almost exclusive to dive bombers, though the air brakes fitted to modern aircraft are often of a similar design.
As planes grew in strength and load capability, the technique became more valuable. By the early 1930s, the technique was clearly favored in tactical doctrine, notably against targets that would otherwise be too small to hit with level bombers. While the USAAC concentrated on mass attacks by very large bombers, the U.S. Navy ordered the first custom dive bomber aircraft, the Curtiss F8C Hell-Diver biplane (not to be confused with the SB2C Helldiver).
Generally, dive bombing was a technique preferred by naval air forces. Their aircraft often had to operate from small airfields or ships, which limited their size. They, in turn, had to attack small, often moving targets, such as ships. The combination of small bombload and need for accuracy made dive bombing techniques more attractive than other alternatives.
For its day, the Stuka was the most advanced dive bomber in the world. Using it as "aerial artillery" solved a major problem in the concept of Blitzkrieg—how to attack dug-in defensive positions. Normally this would require slow-moving artillery to be used, making the fast moving armored forces wait for it to catch up.
This was proven to great effect during the invasion of Poland and the Low Countries. In one particular example, the British Expeditionary Force set up strong defensive positions on the west bank of the Oire River just front of the rapidly advancing German armor. Attacks by Stukas quickly broke the defense, and combat engineers were able to force a crossing long before the artillery arrived.
The Stuka soon grew outdated, and repeated efforts to replace it with a newer and more capable plane all failed. By the start of the Battle of Britain it was already hopelessly outclassed, and suffered at the hands of the RAF.
The most famous example of successful naval dive-bombing attacks took place in the Battle of Midway in June 1942 when American Dauntlesses scored fatal hits on three separate first-line Japanese aircraft carriers within a six minute timespan.
Today, smart bombs are used for precision bombing. Bombs can be dropped many miles from the target at high altitudes, placing the aircraft at little risk. The bomb then guides itself onto the target through a number of means. These include laser designation, onboard GPS, radar, infrared, television guidance, and inertial wind-correction. Bombsights continue to supply several "toss bombing" modes, a sort of reverse dive bombing when an aircraft releases its bomb while steeply pulling up from low level. Shallow, 45 degree or less dive bombing attacks are still used to deliver unguided bombs when they are employed.