The author outlines recent progress by the Engineering Division in the diversified problem of the development of all heavier-than-air equipment, including the 15 types of airplane at present believed necessary to fill Army-Air-Service requirements. The subject is discussed under the headings of the airplane proper, the powerplant, the armament and the equipment, inclusive of illustrations.The development of existing engines, especially the Liberty 12-cylinder type and the Wright 180 and 300-hp. units, is outlined and engine tests conducted with a view to improving engine performance are commented upon. The problems of armament development are stated and the work of equipment development is reported as having been confined largely to crash and leakproof tanks, parachutes, hangars, take-off mats and cameras. Work has been done also on navigation instruments and the use of radio fox navigation.