Like the tank, the aircraft was a weapons system that was introduced in the First World War and proved decisive in the Second. Aircraft had an unprecedented level of mobility, but only within their combat radius of a friendly base. Much of the strategy of the Pacific War was directed towards capturing new bases from which air power could be projected ever deeper into enemy territory.
The aircraft of the Second World War were almost exclusively metal-skinned piston monoplanes. A few fabric-covered biplanes saw service early in the war, and jet aircraft were introduced towards its end, but none of the latter saw service in the Pacific. Metal construction meant greater structural strength, while piston engines evolved to near their practical technological limit, yielding speeds of better than 400 miles per hour. Firepower also increased, from the dual 0.30 machine guns of the biplane fighters of the First World War to eight 0.50 machine guns or four 20mm cannon on the most heavily armed fighters of the Second World War. Bomb loads increased to 20 tons on the B-29 Superfortress, which also had a range of over 3000 miles.
Aircraft could carry out a variety of missions, but no single
aircraft design was effective at all missions. Most aircraft fell into
one of four broad categories, though these had significant overlap.
Reconnaissance Aircraft. The original air mission, reconnaissance is the collection of intelligence by direct observation. While all aircraft were capable of eyeballing the area in which they operated, some aircraft were specifically designed for this role.
Fighters. The introduction of reconnaissance aircraft in the First World War naturally led to the development of fighter aircraft to gain control of the air or deny control of the air to the enemy.
Bombers. Because of their mobility, aircraft could rapidly concentrate firepower at crucial points. In addition, aircraft had a shock value similar to that of tanks. Bomber aircraft were optimized to deliver firepower against surface targets.
Transport. Although
transport by air was the most expensive way to move men, equipment and
supplies, it was also the fastest and most flexible. Transport aircraft
were particularly important in areas lacking normal infrastructure,
including many areas of the Far East and Pacific.
The aircraft specifications given in this encyclopedia have the following meanings.
Crew. The crew of a combat aircraft varied from a single pilot in most fighter aircraft to 13 in the B-17 Flying Fortress. Light bombers typically had a crew of two, consisting of a pilot and radio operator/rear gunner. Some kinds of light bombers, including most torpedo planes, could carry an additional observer or gunner. Medium and heavy bombers typically had two qualified pilots, a navigator, a bombardier, a flight engineer, and a variable number of additional gunners. The non-pilot specialists usually manned a gun when under attack.
Dimensions. These
are the wingspan, length, and
height. The dimensions are particularly important for carrier
aircraft, which must be able to fit onto the elevators and
under the overhead of the hangar deck. The dimensions also determined
how many aircraft could fit onto a carrier flight deck for a deckload
strike. Some carrier aircraft had folding wings to save space.
Wing area. In general, a greater wing area means better low-speed maneuverability and lower takeoff and landing speeds, but at the cost of a reduction in maximum speed. The usual comparison figure is the wing loading, which is the ratio of weight to wing area.
Weight. Usually the empty and fully loaded weights are given. The heavier the aircraft, the more lift was required to keep it in the air. More lift was achieved either by increasing the wing area or by increasing the cruising speed. A light load usually increased an aircraft's range.
Maximum Speed. This specifies the maximum speed the aircraft could achieve in level flight, and the altitude at which this speed was reached. At lower altitudes, the denser air produces more drag, while at higher altitudes, the engine efficiency begins to suffer in the thinner air. Most aircraft of the Second World War had engines equipped with some kind of supercharger to compensate for the thinner air at altitude. Those few that did not had poor high-altitude performance, sometimes to such an extent that their best speed came at sea level.
Cruising speed. This is the speed at which the aircraft achieved its optimal range.
Landing speed. This is approximately equal to the stall speed at sea level. The greater the landing speed, the longer the runway required.
Climb rate. This is a measure of how quickly the
aircraft could gain altitude. It is an important performance
specification
for fighter aircraft. Since climb rate dropped as altitude increased,
we give an average climb rate from sea level to normal operational
altitude.
Service ceiling. This is the altitude at which the rate of climb drops below 100 feet per minute. It marks the maximum practical altitude at which the aircraft can operate.
Power plant. This indicates how many engines the aircraft has, and of what type. Almost all aircraft that saw combat during the Pacific War were equipped with either radial or inline piston engines. Radial engines were air-cooled, which made them less susceptible to combat damage and allowed them to produce more power per unit weight. On the other hand, inline engines had a much smaller cross-section, which usually reduced drag enough to compensate for their greater weight.
Armament. This varied greatly between different aircraft types, but usually consisted of some number of machine guns or cannon. These were either fixed to the airframe, so that they were aimed by pointing the entire aircraft, or they were mounted in flexible mounts or turrets, where they were aimed by gunners. Rifle caliber (0.30 or 7.7mm) machine guns were often used early in the war, but gave way to 0.50 caliber (12.7mm) weapons or cannon that packed more punch. Cannon fired an exploding shell, usually 20mm but sometimes as large as 40mm, which could do a great deal of damage; but cannon also had a lower rate of fire, so that 0.50 caliber machine guns remained competitive with cannon almost to the end of the war.
Some Allied strafing aircraft carried a single 75mm gun. These were useless in aerial combat but could be effective against ground targets.
Bomb load.
This describes the stores that could be
mounted on the aircraft's hard points or in its bomb bay. These stores
included bombs, rockets, and torpedoes,
but also fuel drop tanks for
extending
the aircraft's range or airborne radar
pods.
Range. The range of an aircraft is the maximum distance it can fly before it must land to refuel. It differs from the combat radius, which is the maximum distance from its base that an aircraft can successfully perform its mission. The rule of thumb is that combat radius is about one-third of total range. This means that the aircraft expends one-third of its fuel reaching the target, up to one-third of its fuel maneuvering near the target, and one-third to return home. Aircraft occasionally operated at close to half their range, but this put them at a serious disadvantage because there was no fuel reserve for combat maneuvers.
Fuel. The maximum amount of fuel carried internally by the aircraft. Where more than one figure is given, these specify different internal storage locations, such as wing or fuselage tanks. Fuel capacity of drop tanks is listed under bomb load.
Capacity. For
transport aircraft, this lists the number of passengers or weight of
cargo the aircraft could carry.
Production. This summarizes how many of the aircraft were produced, and over what time period. In the case of Allied aircraft, a large fraction of production went to Europe rather than the Pacific. The fraction of production reaching the Pacific varied from less than 20% for the A-26 to essentially 100% for the B-29 and some of the Navy models.
Variants. Most aircraft models were refined and improved over the course of their production run, so that more than one variant saw combat. In addition, some aircraft models were modified to fill specialized roles. For example, certain variants of the A-20 were produced with transparent noses for a bombardier, so that they could serve as bombing lead ships in Europe.
References
The Pacific War Online Encyclopedia (c) 2007-2008 by Kent G. Budge. Index