Summary: GAO discussed U.S. aviation safety and noted that: (1) the Federal Aviation Administration (FAA) and the airlines have done a good job of fulfilling their safety roles; (2) FAA uses near mid-air collisions and operational errors to measure the safety of the air traffic control system, but has no method for measuring the safety of airline operation and maintenance; and (3) FAA could use the frequency and severity of airline noncompliance with safety regulations as a safety indicator. GAO found that: (1) deregulation has resulted in lower fares, reduced aircraft maintenance, lower flight crew salaries, and increased air traffic; (2) the controller work force has not fully recovered from the 1981 strike and subsequent firing of over 11,000 controllers; (3) delays in airport surveillance radars and in implementing the advanced automation system resulted in delayed controller productivity gains; and (4) although FAA increased the size of its inspector work force, established minimum inspection standards, and affirmed that inspections are a high priority, its inspections and follow-up activities remain insufficient to identify all major safety problems.