J. Lynn Helms, the federal aviation chief who played a decisive role during the air traffic controllers strike in 1981 by advising the Reagan White House that air travel would continue safely if the president chose to crush the labor protest, died Dec. 11 at his home in Westport, Conn. He was 86.

He had cardiopulmonary failure and complications from pneumonia, said his daughter Carole Reichhelm.

Before taking over the Federal Aviation Administration at the start of the Reagan administration, Mr. Helms had built a reputation as a gutsy Navy test pilot and a savvy businessman. As president of Piper Aircraft in the 1970s, he had helped revive the company’s finances through cost-cutting and other measures after years of labor disputes.

In part because of that performance, then-Transportation Secretary Drew Lewis pulled Mr. Helms out of a comfortable retirement and put him at the head of the FAA, which was facing union turmoil of its own.

Although labor officials viewed Mr. Helms with suspicion, admirers praised his unrivaled expertise in flight. Mr. Helms was the first FAA head in years, The Washington Post once noted, who was capable of designing an airplane that flew.

By his own telling, Mr. Helms was not interested in the vagaries of politics and made an early declaration that the FAA would “stay out of the press as much as possible.”

Less than seven months into the job, he found the FAA at the center of national attention when the Professional Air Traffic Controllers Organization went on strike, calling for better compensation and a shorter work week. The move violated a law barring federal workers from striking.

Lewis asked Mr. Helms whether the FAA could ensure that air traffic control would function in the event of a mass firing. Mr. Helms said that it would. In August 1981, President Ronald Reagan began firing about 11,400 controllers who had walked off the job.

In addition to hiring new employees, Mr. Helms kept the FAA running by using more than 8,000 non-unionized workers, managers and members of the military.

While the strike was a defining early moment in the Reagan presidency, Mr. Helms was involved in highly sensitive matters. He helped push through Congress a $10 billion plan to modernize the air traffic control system and participated in international talks after the Soviet military shot down Korean Air Lines Flight 007 over the Sea of Japan in 1983 after the commercial plane flew into Soviet air space.

Mr. Helms left the FAA the next year amid unfavorable media coverage. The Wall Street Journal published an article in 1983 describing the bankruptcies of several business run by Mr. Helms and an associate. He continued to run some of them while at the FAA. The article reported that the government had lent or guaranteed several million dollars of defaulted debt.

Jonee Lynn Helms was born March 1, 1925, in DeQueen, Ark. He never used his first name, which was pronounced “Johnnie.”

After attending the University of Oklahoma, he served in the Navy in World War II. He later joined the Marine Corps and served in the Korean War. After leaving the military in 1956, he became an executive with a series of aviation companies.

Survivors include his wife of 65 years, Lorraine Bisgard Helms of Westport; three children, Loralyn Helms of West River, Md., Carole Reichhelm of Westport and Zackary Helms of Wilton, Conn.; a brother; and three grandchildren. His son Jon L. Helms II died in 1987.

Mr. Helms was a military and civilian test pilot as a younger man. “You can think your way out of most problems,” he once said. He recalled losing control of a jet at 52,000 feet. “Instead of panicking and ejecting,” he said, “I figured out what to do by 12,000 feet.”