Page:CAB Accident Report, Pennsylvania-Central Airlines Flight 142 (1945).pdf/8

 "instrument clearance" by the Airway Traffic Control Center of the Civil Aeronautics Administration in accordance with their practice of approving requested altitudes solely on the basis of other known traffic and without responsibility for terrain clearance, weather conditions, etc. These other factors are covered in the Civil Air Regulations and in the company's operations manual which is submitted to and reviewed by the Adminstrator. The pilot presumably was thoroughly familiar with all these required procedures. - 8 -