The Federal Aviation Administration's medical examination procedures do not identify all airmen who are medically unfit. Additional medical screening techniques are available and should be required. Nineteen of 28 scheduled American passenger airlines require medical examinations which exceed Federal requirements and the International Civil Aviation Organization has published medical standards for airmen which exceed those of the FAA. More extensive medical screening is required of air traffic controllers and military pilots than of civilian pilots. Other sources of information are available which could further help to identify pilots medically unfit to fly. The FAA often is restricted from obtaining this information.