One Hundred Years of U.S. Navy Air Power (37 page)

The USS
Saratoga
(CV-3), recovering her aircraft, June 1935
.

REEVES' CARRIER REVOLUTION

The U.S. Navy of that era was very fortunate in that it tested its ideas on the game floor of the Naval War College, that is, not only at sea (more generally, the War College acted as the Navy's think tank). Although such experimentation might seem the obvious way to develop new technology, the U.S. Navy seems to have been unusual in emphasizing it. The ships and aircraft involved could adopt whatever characteristics seemed relevant to future warfare. Officers could see what the aircraft of the future (rather than existing relatively primitive ones) might contribute to a naval battle. The games showed how important it was to mass aircraft (and also to launch them quickly, as a carrier might easily be put out of action by enemy attack). Captain (later Admiral) Harris Laning encouraged games involving large numbers of aircraft, far beyond what the existing carrier
Langley
could support, and emphasized the need to put the enemy's carriers out of action at the outset. Captain (later Admiral) Joseph M. Reeves took this lesson with him when he assumed command of the aircraft of the Battle Force, which at the time meant mainly the few assigned to
Langley
.
¹³
He had attended the War College in 1923–1924, became head of its tactics department in 1924, and on 1 June 1925 was assigned to the Bureau of Aeronautics. A few days later he went to Pensacola for the aviation observer's course, which would fit him to command an air unit. Once graduated, he was assigned in September 1925 to command Battle Fleet Aircraft Squadrons as senior officer aboard the prototype carrier,
Langley
. Reeves saw
Langley
as the essential school in which U.S. naval air doctrine would be created. She first went to sea, with Reeves aboard, in December 1925.

It was assumed that the aircraft capacity of any one carrier was limited because the Royal Navy, the most experienced carrier navy by far, had reached that conclusion after trials in 1918. Just as aircraft landing ashore would taxi off the runway before the next aircraft landed, the British stowed their aircraft in the carrier's hangar upon landing. That made for lengthy intervals between landings. It also meant that a ship's aircraft capacity was set by her hangar capacity, which in early carriers was very limited. Hence the British insistence on a large total carrier tonnage at Washington in 1921.

Coming from the War College, Reeves understood that he had to pack more air power into the small
Langley
. He found that airplanes did not need the whole deck on which to land. Instead of being stowed below upon landing, they could simply be wheeled forward, protected from landing aircraft by a wire barrier. In this way aircraft could be taken on board much more quickly.
¹⁴
Once all were aboard, they could be moved aft and be massed at the after end of the flight deck. They could take off again, en masse, to attack. In contrast to the British, in this view the hangar was mainly a workshop; many aircraft would spend very little time under cover. By March 1926 it was understood that an American carrier deck should be divided into
three areas, all working simultaneously: a landing-on area aft, equipped with arresting gear; a rearming and servicing area roughly amidships, to prepare a follow-on strike; and a launch area forward. It became clear that launching tempo depended on landing tempo; if the landing interval was too long, aircraft would run out of fuel. Reeves therefore pressed his pilots to fly more precisely so that landings would be much quicker and much safer, with innovations like a circular formation feeding aircraft continuously into the landing area and like the division of the flight deck (aircraft handling) crew into teams with distinctively colored uniforms. As aircraft performance improved, it became impossible to operate the flight deck continuously. Instead, carriers spotted all or most of their strike aircraft aft, launched them, and spotted them forward (in front of the barrier) when they returned. After all had landed, they were all re-spotted back aft for a new strike. This change probably occurred in the mid-1930s.

The use of one end of the ship for landing, the other for taking off, and the area between for parking and servicing, encouraged BuAer to suggest in 1926 that future carriers should be truly double-ended, for greater flexibility, with arresting gear and catapults at both ends. The
Yorktown
s of the late 1930s had arrester wires at both ends, with four barriers between them, but they had only a limited ability to sustain high speed running astern. In theory this made it possible for the ship to launch fighters or scouts even when the bow was full of strike aircraft just recovered and not yet re-spotted. Similarly, scouts might be recovered over the bow when the usual landing area was full of aircraft spotted for a strike. The World War II
Essex
class did have the ability to sustain high astern speed. A few surviving photographs show
Essex
-class carriers recovering aircraft over their bows, running astern. Another means of launching when most aircraft were spotted forward was a hangar deck catapult firing athwartships, a feature of the
Ranger
and later designs (though not installed on board many of these ships).

Langley
ultimately operated about four times as many airplanes as she had before Reeves arrived. From a ship design point of view, Reeves' innovation meant that carrier operating capacity depended on the size of the flight deck and the length of deck airplanes needed to take off, rather than on the capacity of the hangar. It took some years for that to become obvious, because at first the assumption was that aircraft would be placed on the flight deck only when they were about to fly, or had landed. Probably the U.S. Navy took time to realize that aircraft could survive prolonged exposure there (it helped that the U.S. Navy operated mainly in temperate climates). Neither the British nor the Japanese (who began their naval air arm with British tutelage) ever understood this use of the flight deck, to the extent that even many decades later a senior British warship designer asked this author how it was that American carriers packed in so many more aircraft with less hangar space than did British carriers. The radical difference in operating practice was why numbers of
aircraft at the Battle of Midway were fairly equal, even though the Japanese had six carriers to the U.S. Navy's three.

It may have been key that Reeves was not a pilot (he had trained as an observer); he understood what naval aviation could provide to the fleet, but he was not viscerally aware of just how dangerous carrier operation could be. To a pilot, it must have seemed unnatural to land an airplane into a mass of parked aircraft, relying on arresting gear and a barrier to keep from crashing into them. The British based their own estimates of carrier capacity (and their operating practices) on pilots' views, because from 1 April 1918 on, their naval aircraft were operated by the new Royal Air Force. It is striking that the U.S. Navy often discussed—and accepted—the dangers of carrier operation, to the point that films of the classic era of carrier aviation seem incomplete without numerous crashes, many of them fatal. A memoir of interwar British carrier aviation was titled
It's Really Quite Safe, You Know
. American observers were surprised by how casual British carrier landings seemed. U.S. landings were highly disciplined because they had to be so precise to engage the arresting gear in the right place (for many years the Royal Navy did not even use arresting gear). About 1930 the Royal Navy finally realized that it could operate a lot more aircraft by adopting U.S.-style deck parking. Nothing happened, because by that time the British Air Ministry feared that total British aircraft numbers would be limited by a future disarmament treaty; it did not want the Royal Navy to consume too much of that limited pie.

Reeves' operating technique shaped U.S. carrier aircraft. Carriers had catapults, but they were not considered very effective, so aircraft generally rolled down the flight deck to take off. Carrier capacity was determined by how far aircraft had to roll, because when the carrier launched all her aircraft for a strike the first airplane had to start out from just ahead of a mass of aircraft parked on the after part of the flight deck. Generally the requirement was that the airplane be able to take off in four hundred feet in the twenty-knot wind the ship could generate. It turned out to be quite acceptable until the end of World War II. Among other things, it meant that a ship with a relatively short deck could operate modern carrier aircraft as long as she was assigned a small enough air group that they left the necessary four hundred feet of deck. That became very important during World War II.

Given U.S. operating practice, carrier deck capacity could be set either by the required landing area plus the spotting area used by aircraft once they landed, or by spotting area plus the takeoff space needed by the first airplane. Between 1930 and 1939 takeoff run increased by 93 percent—but average carrier deck length increased by only 7 percent. Higher aircraft performance required higher wing loading, which in turn increased the takeoff run—which was one reason catapults became increasingly important during World War II. They were disliked because they greatly increased the interval between launches, but without catapults the need to match
increasingly powerful land-based aircraft would make it more and more difficult to operate enough aircraft on a carrier; ultimately airplanes might need the whole flight deck merely to take off. That is what happened as jets entered service; they became usable only as powerful enough catapults entered service.

Landing space depended on the airplane's stall speed, which rose by about 13.5 percent in 1930–1939. High lift devices were applied from 1935 on, and this reduced stall speed and enabled a slower approach speed. To the landing area had to be added the run-out of the arresting wire, which absorbed the energy of the landing airplane (in 1939 this distance was 40 to 100 feet). The overall length devoted to landing was about 315 feet, including the run-out. If this length were not increased as landing speed increased, then the rate of barrier crashes would rise; the rate for 1937 was 1.11 per 1,000, cut to 0.96 in 1938 but increased to 1.23 in 1939. Since carriers could not grow to keep pace with the higher performance airplanes introduced during and after World War II, it was not surprising that crashes became more common—that the existing form of flight deck was perceived as more and more dangerous. The number of aircraft that could park on deck depended on the area per airplane, which until 1936 fell as biplanes became more compact, with higher wing loading, but then grew as monoplanes entered service.
¹⁵

If a carrier (like
Ranger
) had too small a deck, she could not spot all of her aircraft on deck. Some aircraft had to go into the hangar after landing. U.S. hangar design practice (open hangars) made that more acceptable, as these aircraft could warm up for flight while still in the hangar, then be brought up onto the flight deck ready for launch, after the aircraft already there had been launched (
Lexington
and
Saratoga
struck a few aircraft below deck as they landed, but could not warm them up in their closed hangars; in 1940 plans were under way to improve their ventilation). By 1940 this argument applied to the new
Essex
class, which would almost certainly have to operate multiple generations of higher and higher performance airplanes. If the aircraft operating cycle once again depended on elevators, their speed and location became crucial. The forty-five-second operating cycle in the
Yorktown
s might be too slow, since carriers enjoyed a sixteen-second minimum launch interval. On the other hand, feeding one hangar airplane for every two on deck would make up for the elevator cycle. It turned out that elevator speed could not be increased significantly. Nor could many more elevators be provided in the right places. For example, particularly given the argument that planes from the flight-deck spot should be mixed with those brought up from below, it was essential that at least some elevators obstruct the flight deck to the minimum possible extent. Similarly, the elevators should be brought toward the middle of the ship so as to limit their effect on launching and recovery, and so that two elevators might be usable for either (i.e., both had to be clear of both deck parks). The position amidships (lengthwise) was particularly valuable because it would be just forward of the landing area and just abaft the
launch area (if that were possible, given lengthening takeoff runs). It was also preferable, for handling in the hangars, not to place any elevators near the ends of the hangars. Typically U.S. carriers had their hangars divided into thirds by fire curtains, so they had one elevator per hangar bay. In 1940 the U.S. Navy was experimenting with a solution to the elevator problem, a deck-edge device that rose and fell away from the traffic on the flight deck. A simple elevator was tested in USS
Wasp
, and a much larger one was designed into the
Essex
class. The elevator design in the
Essex
class was based on that of the stage of Radio City at Rockefeller Center in New York, which could be raised and lowered as needed.