• The Need for Reform
  • A Visionary Reforms the Airline Industry
• Cross-Country by Air and Rail
• Aviation Becomes Big Business
• The Air Mail "Scandal"
• The Triumph of Technology
  • The NACA and the Modern Airliner
  • Results: NACA Contributions
  • What Makes an Airliner "Modern"?
• The Creation of the Modern Airport
  • Yesterday's Airports of Tomorrow
• The Beginning of Air Traffic Control
• Early Pilot and Flight Attendant Uniforms
• What Was It Like to Fly?
• Who Flew?
• Pan American Airways
  • The China Clipper
  • Aircraft

Automatic Direction Finder

Developed by the Sperry Gyroscope Company, automatic direction finders (ADF) were first installed on aircraft in the mid-1930s.
Gift of Charles L. Neumann

Image number 2007-13184
Credit: Smithsonian Institution, National Air and Space Museum

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