J. Lynn Helms, 86, who as head of the Federal Aviation Administration supported President Ronald Reagan's decision to fire more than 11,000 striking air traffic controllers and who subsequently helped restore the nation's crippled air traffic system, died Sunday after several bouts of pneumonia at his home in Westport, Conn.

Mr. Helms, a decorated pilot who left the Marine Corps as a lieutenant colonel in 1956, went on to a successful business career in aviation. In 1974, he became president and chief executive of Piper Aircraft and was credited with turning the company around financially before Reagan appointed him to lead the FAA.

When he assumed the post in April 1981, a confrontation with the Professional Air Traffic Controllers Organization, known as PATCO, was imminent. Mr. Helms negotiated a cooperation agreement with commercial airlines and helped secure assurance from the Pentagon that military air controllers would be available to step in.

Federal law prohibited federal employees such as the controllers to strike. But on Aug. 3, demanding higher pay and a shorter workweek because of the stressful nature of the job, nearly 13,000 walked out. Only about 10 percent returned to work after Reagan threatened dismissal of anyone who remained out after 48 hours.

- N.Y. Times News Service