The aerodromes are the headquarters of the different squadrons, each of which is specialized in some type of work. Military aviation divides itself into certain groups, requiring different types of machines and different training for pilot or observer. These groups are day-bombing, night-bombing, observation, photography, artillery fire-control, and chasse. I would like to tell you all about the different buses used, but of course one is not at liberty to do so. In general, bombing-machines are rather large two-seaters or three-seaters, designed to rise to great heights, where they are very fast, and capable of carrying heavy loads for long distances. They are, naturally, well armed, but depend (for safely carrying out their missions) principally on their speed at altitudes of eighteen thousand feet or more. Photography, observation, and artillery control machines, on the other hand, must be fast at lower altitudes, handy in a fight, and speedy climbers. They are, so far as I know, always two-seaters, and are really the most important of all aeroplanes. I believe that all the allied designers should work together to produce a single uniform type of two-seater--small, quick to maneuver, and very fast up to fifteen or sixteen thousand feet. Such machines, flying about their work in small groups, are truly formidable things for single-seater scouts to attack, as they are nearly as fast and handy, and have the enormous advantage of being able to shoot backward as well as forward. With light double-controls for the machine-gun man or observing officer (who would take a few lessons in emergency flying), they could not be brought down by killing the pilot--a most valuable feature.
The Boches have such machines,--particularly the Rumpler,--which are tough nuts to crack, even when outnumbered. Two of our boys had a running fight with a Rumpler recently, and dove at him alternately for thirty minutes over forty miles of country. Both were nearly brought down in the process--and they failed to bag the enemy machine, though at the last they did for the observer. This shows the great value of the fast two-place bus. I doubt if people at home are aware of the difficulties of designing a two-seater which one could pronounce, without hesitation, the best. It must have four major qualities: speed, climbing ability, diving speed, and handiness. The need of strength, or high factor of safety, goes without saying. Speed is simply a matter of power and head resistance, and is comparatively easy to attain alone; the rub comes in combining with it the requisite climbing power, and factor of safety. The Germans, in general, seem to believe in a very heavy, substantial motor, which cuts their climbing to a certain extent, but gives them a very fast dive. The Allies' machines, I should say, are slightly faster climbers, but cannot follow a diving Hun. And so it goes--to have one quality in perfection, another must be sacrificed.