2–4 March 1943) achieving considerable success with skip-bombing.
Italy had a unified air force (like the RAF), although the Royal Italian Navy retained ship-based floatplanes and seaplanes. Air unification probably prevented the navy from building the carriers it wanted during the inter-war period (it finally received permission during the Second World War, after the Royal Navy demonstrated the value of carriers).
Air Attack
Before the advent of guided weapons, an aircraft delivering an attack was, in effect, the gun launching a projectile. The pilot gave the projectile both direction and forward velocity. Accuracy depended both on how well he aimed and on how well the projectile (bomb, torpedo, later rocket) followed through. The pilot’s need to steady up on course in order to aim was the main opportunity afforded the anti-aircraft defence, since until then the pilot was more or less free to manoeuvre. Conversely, anti-aircraft fire could ruin a pilot’s aim by forcing him to manoeuvre instead of steadying on course. The only exception to the straight run was that, like its sea-launched counterpart, an aerial torpedo could, at least in theory, be set to turn (angle) after launch. This possibility seems to have been realised only by the British, the Germans, and probably the Italians.
Prior to the Second World War it was accepted that a fleet in harbour might well be subject to night attack – as at Taranto in November 1940 – but it seems to have been assumed that ships at sea would be too difficult to locate. That was not at all true on a moonlit night, as wakes could be very visible. They were often phosphorescent, too. Night attacks on moving ships at sea, which were first mounted by the Italians in the Mediterranean in 1940, changed the situation considerably. Airborne radar much simplified night attack, although blind attacks were not possible until the advent of centimetric radar, which was limited to the Allies. Night also limited fighter defence. Even in 1945 the US Navy operated special ‘night carriers’, the other carriers being limited to day aircraft. Ships’ guns were the main night fleet air defence, and they were limited by the development of radar-controlled blind fire. As late as 1945 US doctrine for night convoy air defence was to make smoke and not to fire unless attacked, because muzzle flashes would become aiming points for the enemy.
For the inter-war US Navy, the single most important aviation development was the discovery of just how many aircraft the two huge carriers Lexington and Saratoga could operate. Exercises at the Naval War College showed that numbers of aircraft were paramount, and when he became Commander of Air Squadrons of the Battle Fleet (which then had the single small experimental carrier Langley) Captain Joseph M Reeves, Jr. asked his pilots how they could operate more aircraft. They discovered that instead of striking aircraft below as they landed – as in the Royal Navy – they could have them moved forward, protected from landing aircraft by a wire barrier. That made for a much shorter interval between landings. The shorter interval supported a much larger carrier air group. This was an inherently dangerous procedure, but it worked, and it gave the US Navy considerable numerical advantages over the Royal Navy and the Imperial Japanese Navy (which followed British operating practice). Unlike the British and the Japanese, the US Navy equated aircraft capacity to the size of the flight deck, which determined how many aircraft could be parked forward during landing, or how many could be spotted aft before take-off (leaving enough of a deck run to take off). Huge US carrier air groups made the balance of air forces at Midway much closer than the ratio of carrier numbers (four to three) might otherwise suggest. Its numerical advantage in turn made the US Navy more conscious of the value of carrier fighters, because it could have both a large fighter complement and a large striking force, even of massive torpedo bombers. Once it also had radar, the fighters made an enormous difference in fleet air defence. The US operating practice did have its drawbacks, however. With the deck loaded aft for a strike, it might be difficult to recover scouts. With aircraft filling the foredeck, it might be difficult to launch them. Arresting wires were rigged at the bow as well as the stern. The carrier would steam astern to recover aircraft: Essex class carriers were designed to steam astern at 20kts on a sustained basis. To launch aircraft when the deck was full, they were given hangar-deck catapults. Neither solution was particularly happy, and the US Navy was fortunate that it learned how to operate multi-carrier Task Groups, whose extra decks were a better solution. Conversely, the Royal Navy accepted many compromises, even in aircraft performance, because it assumed that its ships could accommodate so few aircraft. When it wanted more aircraft per carrier, it adopted double hangars, with their limited head-room (which made post-war modernisation of some wartime-built ships impossible). Saratoga is shown recovering her T4M torpedo bombers in the early 1930s. Unlike later US carriers up to 1945, she had a British-style closed hangar. That in turn made gasoline vapour explosions more devastating – and one such explosion doomed her sister-ship Lexington (the Japanese closed-hangar Taiho suffered a similar fate). Later US carriers had open hangar decks, which made it possible to warm up engines on them; that in turn made for faster launching of aircraft which had to be held below because they did not fit the parking area on the flight deck (whose size was set by the required take-off run).
The one ship-killing air weapon used during the First World War was the air-dropped torpedo, first employed by the Royal Navy and intended for mass use against the German High Seas Fleet had the war continued. This US Navy torpedo bomber has just dropped its weapon off Pensacola, 28 April 1920 – and it has porpoised. In 1922 the shore-based Torpedo and Bombing Squadron of the Atlantic Fleet successfully attacked the battleship Arkansas when she was steaming at full speed 70 miles from Norfolk. They made at least seven hits on her, and a miss hit the battleship North Dakota. This exercise demonstrated that air-launched torpedoes could be made to run straight, apparently an issue at the time.
It took time for navies to develop effective air-launched torpedoes and the tactics which went with them. Even then, the torpedo was by far the heaviest bomb load navies contemplated, and until the advent of engines in the 1000 and 1500hp class in the 1930s, torpedo bombers were invariably heavy and slow. The first production US Navy torpedo bomber, the T4M-1 of 1928, had a maximum speed of 114mph and required 14.1 minutes to climb to 5000ft. The Depression precluded replacement of the T4M, or even an upgrade with the new R-1820 engine, as proposed in 1931. The T4M could carry a torpedo or 1500lbs of bombs, and that became the standard for the next torpedo bomber, the Douglas Devastator. Given the combination of heavy bombing and torpedo attack in one aircraft, the inter-war US Navy assumed that carrier air strikes would mix the two types of attack, which would be combined with dive bombing by other aircraft. These T4Ms are shown on board the carrier Saratoga.
Reconnaissance was always the first step in an air attack: the sea is broad, and even a large convoy or fleet is only a small speck on it. Attackers with heavy loads had insufficient endurance for any kind of search. Instead, reconnaissance aircraft or ‘snoopers’, often cued by other intelligence, found the target and homed the attackers.8 Destroying a snooper might prevent an attack altogether. Since ships could generally be seen and shadowed from well beyond anti-aircraft gun range, it took fighters to deal with snoopers.9
Torpedo bombing
During the First World War, torpedo attack was the only form of air attack which actually sank moving ships at sea. It was practiced by both the British and the Germans, and in 1918 the British planned a mass torpedo attack against the German High Seas Fleet in harbour, to be mounted from aircraft carriers. The war ended before the plan could be executed.
To be effective a torpedo had to be relatively massive. Until the Second World War, engines suitable for carrier aircraft were not powerful enough to give a large enough aircraft an impressive performance. In the early 1930s the US Navy nearly abandoned the torpedo as an air weapon, reversing
