John F. Dealy's resignation on Feb. 3 as president of Fairchild Industries after 14 eventful years with the $1 billion Montgomery County aerospace company was certainly sudden. It was not unfair, however, as Dealy measures fairness.

There is no visible trace of bitterness on Dealy's part now as he closes the Fairchild chapter of his life and prepares for a new assignment teaching senior and graduate students at Georgetown University.

He has cushioned his departure with a million-dollar settlement from Fairchild that confirms his credentials as a tough bargainer. Fairchild disclosed in its proxy statement last week that it has paid Dealy $500,000 in cash and will make five additional annual payments of $100,000 each beginning next year. Dealy received a base salary of $225,000 and total compensation of $366,212 last year under a contract that ran through August 1983.

Dealy and Fairchild both agreed not to discuss the reasons for his departure. Other sources say the central issue was whether Dealy would be chosen eventually to succeed Edward G. Uhl as chairman. Dealy says merely that "a combination of cuts and bruises over many years" was involved. "I drove the company very hard," he added.

But Dealy does say that emotionally, the departure has been eased by principles of his personal philosophy, one of which holds: "Life is unfair." A second: "Treat today as if it's the day you get fired."

His personal philosophy and the lessons learned in his rise to the top at Fairchild will be the basis of his post at Georgetown, where he will have the title "distinguished professor."

He begins this September with a course on business policy for seniors, and in January 1983, he will start the "capstone" course at Georgetown's graduate business administration program. Also in 1983, he will add a course on technology and business and will teach at Georgetown law school as well.

"I'm looking forward to working with students. There are things for me to learn," Dealy said. "In business, you learn certain ways of doing things, then you repeat the process over and over again. The intellectual environment at Georgetown will be a pleasant change." He also plans to be a management consultant to communications and technology companies in the Washington area.

Dealy was a 28-year-old lawyer when Fairchild hired him as general counsel and director of contracts in 1967. Despite his relative youth, Dealy had natural credentials--the job he left to join Fairchild was attorney-adviser to the secretary of the Air Force, handling procurement and program management assignments.

His re'sume' charts a meteoric rise in the company. In 1968, a year after he joined Fairchild, he was a vice president. By 1976, he was president. "When I came to Fairchild, it had a lot of problems," Dealy said. Its survival in the competition with giant aerospace companies was in doubt, and it was fighting desperately to come up with a major prime defense contract.

The "win" came with the selection of Fairchild in 1970 to build a prototype of the A10 close-combat support aircraft, which would become Fairchild's largest military program, adding more than $3 billion to sales in the 1970s. Dealy headed Fairchild's initial A10 campaign.

He also led a successful protest campaign by Fairchild to overturn the award of a major communications satellite contract to General Electric Co. and get the business itself. Fairchild won, thanks to a six-month, day-and-night push that involved a carefully orchestrated bid for press and political support. The program was the catalyst for Fairchild's satellite and spacecraft businesses, Dealy says.

In 1976, Fairchild's sales were $263 million, its profits $4.9 million and its employes, 7,800. By December 1981, sales had climbed to $1.3 billion, profits to $64 million, and its employes numbered 18,000. Its former base in military contracting had been expanded to include major commercial ventures, to provide protection against the ups and down of government contracting work.

Last year was one "mixed with success and disappointment," the company noted in its annual report. Fairchild suffered operating losses on three commercial aircraft projects after facing difficulties in meeting delivery schedules for sections of Boeing 757 aircraft and high development costs in its Merlin and Metro turboprop business aircraft.

These difficulties, however, did not produce a showdown between Dealy and Fairchild's board, sources said.

Uhl and Fairchild's directors apparently concluded that Dealy wasn't to be successor to Uhl, the chairman and chief executive officer who was president of Fairchild for 15 years until 1976. Uhl, vigorous and intensely involved in Fairchild's management, had determined to begin a final search for a successor, said one source close to the company.

When it became clear that Dealy wasn't the one, he and the company agreed to go their separate ways, said several sources close to the company.

As Dealy tells it, he spent his 14 years at Fairchild prepared for that day. A manager needs to treat each day as the last, Dealy said; otherwise, job security issues become paramount and start to color decisions.

"You aren't being paid $50,000 or $60,000 a year to say 'yes' to your boss," Dealy said.

If you believe that a job is a temporary thing, you don't live beyond your financial means, and you aren't so dependent on your job that you can't walk away from it, he said. "The result is, you end up serving your company better." Dealy and his family live in the same house they bought in 1971. There is a 1973 Oldsmobile in the garage along with a 1980 model.

The notion that life is essentially unfair came from a Jesuit high school Latin teacher who permitted the students to vote on whether there should be homework assignments over weekends, and the outcome was routinely disregarded by the teacher.

The point, Dealy says, was that the decision, arbitrary or not, was a reasonable extension of the teacher's authority. The students had a right to be treated reasonably--but no rights beyond that. To base a life on expectations of fair treatment is to surrender too much personal responsibility for what happens, he says.

There are many other things he wants to talk to the Georgetown students about.

* They will face an environment of great uncertainty and sudden changes, he said. "When I entered the business world, stable interest rates were a given. Metals and fuels were assumed to be readily available. Many of those givens are no longer that, but day-to-day uncertainties.

"Today, senior managers tend to regard these as evils that someone should correct instead of fundamental facts of life."

* The explosion of new information-processing equipment that promises to improve business decision-making can work the other way unless business managers learn to control and limit the amount of information they receive.

* You can't become a slave to your own strategy. Beginning in 1972, as the first step in a move into broadcast communications, Fairchild purchased several radio stations. It soon became apparent that the management style of the radio broadcasting executives was far from the temperament of Fairchild's executives, that the relationship between "idea" people and engineering people wasn't going to work.

The stations were sold and Fairchild's lesson from that "minor debacle" was to be much more careful in making acquisitions, to see that there is a natural bond between the merging companies, he says. As a company expands horizontally, there must be some common thread uniting the various enterprises, Dealy says, or else the parts are left to rise or fall on their own, without a significant contribution by top management.