THE information given in this paper was obtained principally from trip icing logs and test flights conducted on a major transport system. A copy of a trip icing log is included to show the type of information obtained from normally scheduled flights.
The different types of ice formed are explained and the general effect upon the performance on the airplane for each type of ice is stated.
Airplane ice accumulations are divided into two major classes: (1) Those producing a loss of flight performance and (2) those which serve as an annoyance to the crew. The main portion of the paper deals with these two classes, explaining when, how, and why they are of importance. Numerous pictures are shown depicting the various conditions which were found to exist in scheduled airline operations and the shortcomings of the present anti-icing equipment is explained.
Consideration is given to ice accumulations on the wings, empennage, propeller, pitot mast, radio loops, windshield, and so on. It is hoped that a dissemination of these actual airline operating conditions and experiences will result in further improvements to airline anti-icing equipment. It is also hoped that instrumentation means will be developed whereby ice accumulations can be better analyzed and reported.