The merits of the two primary kinds of heavy bombing have been so clearly demonstrated during the past weeks by operations in western Europe and in the Pacific that observers of the air war in London are attempting to form conclusions.
Battle bombing, as it might be called, in which heavy bombers fight their way through to their objectives by day, has been used against both the Germans and the Japanese. Undercover bombing, by which aircraft evade the enemy defenses through the use of darkness or cloud, has also been used.
Military opinion from the first has been divided on the merits of the two methods. In the Royal Air Force there has always been a majority view among senior officers that heavy bombing by the battle method is uneconomic.
In 1936, when the Air Staff was engaged on the specifications which eventually gave rise to the Lancaster, the Halifax and the Stirling, there were vague hopes that the development of the power-operated gun turret would allow the heavy bomber to fight its way through fighter screens. But there was always the intention to turn to night bombing should the assault losses prove too high.
Losses did prove too high. When the Lancaster came into service it was first sent out on a daylight raid on Augsburg, a distance of 500 miles. This was in April, 1942, and of the 12 Lancasters that set out only five got back, though on this mission they were, of course, by reason of their low-flying tactics, exposed to all types of ground antiaircraft weapons.
It would appear that from that time on the Royal Air Force turned to undercover bombing for its heavy planes. When the United States Army Air Forces expressed its intention of coming to Europe to do battle bombing, some Royal Air Force officers advised against it.
They said that the whole of air war history showed that the heavy bomber must suffer uneconomic losses if it tries to fight its way through interceptor screens in full daylight.
There is the fundamental division of professional opinion. On one side there is the view that the heavy bomber cannot fight through but must keep under cover; on the other side there is the view that improved armor and armament should enable it to do so.
I think that we have reached the point where a choice may be made between these two views. I think that the war communiques reaching London during the past two months, taken with earlier experience, permit the statement that assault attacks by heavy bombers against a well-equipped enemy are militarily uneconomic. I would say that the heavy bomber, to be fully effective, must work under cover.
Although the German air force has been hit hard and repeatedly by the air forces of the United States, Russia and Britain, it is necessary today to provide every heavy bomber formation that goes out to hit Germany in full daylight with an escort of fighters at least as numerous as itself.
Sometimes one and one-half fighters go out for every one heavy bomber. Only on the rarest occasions is there fewer than one fighter for every bomber. When they operate against battered Germany and the battered German air force the heavy bombers must have strong escorts if they are not using the cover of darkness or cloud.
Only in the Pacific is an exception to this rule to be found. There the Superfortresses are attacking Japan without fighter escort. But I believe that the reason for their success is technical rather than tactical,
We may say, therefore, that the courageous experiment with unescorted heavy bombers, made by the United States Army Air Forces and particularly by the Eighth, from England, has failed. We have returned to heavily escorted or under cover bombing.
In London the American experiment was watched with intense admiration and interest. If the Fortresses had proved that they could fight their way through to their objectives in full daylight without fighter escort they would have changed the fundamental pattern of air war.
In full daylight their bombing could be more accurate than the RAF night bombing, even when this was aided by the pyrotechnic markers laid by the Pathfinders. But the fighting was grim. At one time the massed .50-caliber guns looked as if they were going to beat the Mauser cannon of the Messerschmitt Me-109s but it turned out otherwise. The fighter escorts had to be brought in to hold off the enemy interceptors
It must be remembered that the heavy bomber, going out in full daylight, even when it has a fighter escort, must devote a larger part of its useful load to guns and ammunition than the under cover bomber. That is one reason the RAF heavies carry bigger bomb loads than the comparable American heavies.
We may set out what has been learned about heavy bombing, and has been confirmed by the latest operations over Germany, as follows:
In manpower, fuel consumed, ammunition used and organizational demands the under cover bomber is superior against a well-equipped enemy to the full daylight fighting heavy bomber which I have called a "battle bomber."
The Superfortress is succeeding against, Japan because it is technically ahead of Japanese equipment. When a new aircraft comes out it may for a time be able ta break the "rules" of air war by virtue of its technical superiority.
As jet and rocket fighters come into service in greater numbers the heavy bombers will need cover or yet stronger escorts. It is time that those who plan technical development gave up the illusion of the self-defending heavy bomber. Self-defense is sometimes possible for a light bomber
But even here escort is sometimes needed. When the force of Mosquitos under the late Group Capt P C Pickard (of the film "Target for Tonight" ) made their jail-breaking attack at Amiens on the morning of February 18, 1944, to release 100 French patriots who had been condemned to death by the Germans, they had a fighter escort.
If these views are right, heavy bombing will tend increasingly to be done under cover of clouds and darkness. Full daylight bombing will become the responsibility of the light, high-performance bombers and fighter-bombers.
It follows that new instrument developments will exert a powerful influence upon the weight and effectiveness of the attack. Great progress has been made in instrumentation for heavy bombers bath in the United States Army Air Farces and in the RAF.
It can be said, however, that we are near the time when an aircraft working entirely on instruments will be able to find a Japanese battleship in mid-Pacific, bomb it by instruments, and return without ever getting a direct visual sight on the target.
Generally speaking the finding of a target is still largely dependent upon that age-old device, the magnetic compass, and the only advance on this is the new American flux gate compass. This, although still fundamentally magnetic, does not use an ordinary magnetic element.
Most other developments depend upon associating a gyroscope with an ordinary magnetic element and this has been the line of progress of the Royal Air Force. The gyroscope has been experimented with by British workers since 1917 (at one of the Royal Flying Corps research stations) with the object of causing it to stabilize and to iron out the errors of the ordinary magnetic needle.
Once the turning and acceleration errors of the magnetic needle can be eliminated, it can be linked up with the automatic pilot, with bomb sights and with other equipment. It becomes useful in blind bombing or bombing in bad visibility.
When it is worked in with radar aids it can transform the whole picture of under cover bombing. In short, it would seem that the future of the heavy bomber lies largely with automatic and semiautomatic navigation and control.
Perhaps it was reasoning of this kind that led the enemy to devote so much effort to V-1 and V-2. But although his reasoning was right, his timing seems to have been wrong. He began to use his flying bomb before the heavy bomber, working in full daylight but with strong escort, had had its say.
Enjoying a marked production superiority over the enemy, the Allies have been right in paying so much attention to the heavy bomber. To them the heavy bomber has been of great service. It is only when one takes what it has done as a basis for trying to forecast future developments that one sees it is approaching the limits of its powers in some fields. In the future it must work increasingly in clouds and darkness, while the daylight precision work must be transferred to ultra-high performance medium and light bombers. And even they may have to call on fighter escorts to penetrate screens of jet and rocket fighters.
This article was originally published in the March, 1945, issue of Flying magazine, vol 36, no 4, pp 52, 148, 150.
The PDF of this article includes a photo of a formation of B-17Gs and B-24s at altitude.
Photo credited to AAF.