Frederick William Lanchester

“ The relation of the ordinary flight velocity to the mean velocity of the projectile is round about 12 to 1, and this gives the angle of lead necessary to aim in front of the objective from a fixed mounting. When firing from another aeroplane moving in the opposite direction, the angle of lead will be six to one more or less, a considerably greater allowance than is known in any other branch of gunnery. With the highest muzzle velocity and slow-moving aircraft the angle of lead under these conditions is about 1 in 15. ”

“ Beyond this the steel dart, to be effective, must be dropped from a height—a very considerable height—and so it is not possible to make a sudden descent for the purpose of bringing off an attack, as is the case when the bomb is the weapon chosen. For these reasons the author does not believe that the dart will have a very great vogue. Once the aeroplane has been satisfactorily adapted to the carrying of a machine-gun, it is quite clear that the steel dart, weighing, as it does, as much as the ordinary Service cartridge, must be regarded as a weapon of doubtful utility. ”

“ It may be said that whereas the hand-grenade, in common with the machine-gun, is only suitable for injuring personnel, the legitimate objective of the bomb is materiel. Thus the depots, magazines, arsenals, oil stores, etc., of the enemy cannot be effectively destroyed by gun-fire, at least from present-day aircraft ”

“ The determination of the vertical, or "plumb," is far less simple or certain than may at first sight appear, since any pendulum device is affected by acceleration just as much as by gravity, and the reading of a damped pendulum or a spirit-level gives the apparent plumb, which may be literally anywhere.
In the case of a machine "looping the loop," for example, the apparent plumb is, in fact, at one instant diametrically opposite to the true plumb, and during the whole evolution it "boxes the compass" in a vertical plane. ”

“ But it is probable that in all cases in which an attack is made upon buildings of permanent character, such as in the destruction of an arms or ammunition factory, or of a dockyard, the petrol bomb will be used to complete the job by firing the wreckage remaining after high explosives have done their work. ”

“ The angle of lead given by a pigeon-shot when the bird is flying fast across the line-of-sight is about 1 in 20, and even here the demand, under the stress of competition, is for higher and higher velocity. ”

“ For the fighting aeroplane there is no doubt that the gun will prove to be the most useful all-round weapon; however, several other means of offence have been suggested and to some extent have proved themselves of value. ”

“ We may take it that in the future any such points will be duly protected by the fighting aeroplanes of the enemy. Consequently the bomb-dropping machine will need to be also a fighting machine itself, with a capacity for rapid fire sufficient to enable it to hold its own with the enemy. ”

“ The penetration at this velocity should be equal to several inches of spruce planking. Steel darts are either allowed to fall out of a hopper or may be simply thrown out or "sown" by hand. They appear to be quite effective when they find their mark, but their discharge and direction are subject to the same limitations as to accuracy which apply to the throwing of the hand-grenade or bomb, with much greater uncertainty as due to air resistance. ”