Notes on Enemy Bombsights

AS little information has been published, the subject of bombsights is shrouded in mystery, and hence from time to time it is natural that the daily press should make amazing disclosures concerning the alleged performances of new types of bombsights; including an American one capable of dropping bombs into a barrel from the sub‐stratosphere. Such statements can be viewed in their proper perspective if the functions of a bombsight are understood. The state of the enemy ground defences dictate the requirements of a bombsight, since if no opposition is met it is possible to drop delayed action bombs from a low altitude without using a bombsight. As ground defence improves, it is necessary to bomb from a greater height, and so the need for a bombsight increases. It is also necessary to bomb from a great height if armour‐piercing bombs are used, so that they can attain their terminal velocity. Unfortunately, or fortunately, depending on one's position at bomb release, accurate bomb aiming is a complicated matter, and errors increase with height. Thus, as high altitude bombing becomes necessary, so the bombsight becomes more complicated, and as ground defences become more accurate the operational difficulties of the aircraft increase and make still further demands on the bombsight. Thus, as the war proceeds a steady evolution can be observed in the types of bombsight used, as will be seen from those described in this article. Anti‐aircraft gunsights have progressed from simple open ones to those incorporated in the predictor system, and in a like manner bombsights have made similar progress. As each sight has had a bearing on the design of the other, it is interesting to compare the requirements and operation of a bombsight with those required for an anti‐aircraft gunsight.