Supercharging a Pressure Cabin Airplane

Abstract

Before introducing the speakers that have been scheduled to read papers in this session, your attention will be invited to a brief general survey of the problem under discussion. To begin with, the title of this session might well be changed so that it would fit more exactly the precise ends toward which the attention of this group is for the moment directed. Instead of referring to High Altitude Flight, it might be closer to practical aims if the expression High Level Operation were used. Under the loose category of High Altitude Flights are included all the dashes to high altitude that have hitherto been made for records, for science, for glory, or as a necessary part of a military program. The predominant dimension of these interesting and colorful flights has been vertical—''up and, almost immediately, The predominant circumstances have been discomfort and danger. High Level Operation can best be described as the addition of useful horizontal dimensions to the limited vertical movement involved in previous high altitude flying. Conversely, it might be described as the addition of a greater vertical dimension to the limits bounding present commercial and military operations. Altitude flights of the past have been carried out in special airplanes or balloons, by specially selected and prepared individuals and under circumstances of great—almost unbearable—discomfort and of tremendous risk. All of this work has been valuable and intensely interesting both from a scientific and a human standpoint. But it has been adventure in the purest sense—the exploration of the unknown and mysterious by picked individuals in special and intriguing equipment. This group is to consider the technical aspects of actually carrying out every day operation at high levels; levels not hitherto visited excepting by the stratosphere and sub-stratosphere explorers on their way up or down. The position of the Army Air Corps in this matter must be made clear inasmuch as a large part of the material to be presented at this session comes from the Materiel Division. The Air Corps is exploring the situation—not expounding or urging on any one else a new development. The work that has been done is part of the program to look into and examine all possible expansions of mobility—which, after all, in one form or another, is the stock in trade. Therefore, the question as to whether commercial carriers should go to high levels is one for these carriers to decide from their three well-known and familiar standpoints: safety, economy, and effectiveness. The Army has developed one method of operating at high levels, over long distances and at increased speeds, with a minimum of discomfort to passengers or of strain on the crew, but at the expense of a certain increase in weight and cost of the aircraft. The Air Corps feels that the experimental program carried out at the Materiel Division with the help of John E. Younger of the University of California and of the Lockheed Aircraft