A special Federal Aviation Administration investigative team, formed in June after two in-flight emergencies on Republic Airlines, discovered a pattern among Republic crews of sloppy discipline, poor coordination and "near total noncompliance" with fuel planning procedures, according to the team's report.

By all accounts, Republic acted quickly to correct those major safety problems, but the findings underline the broader question of why day-to-day FAA surveillance did not discover them.

There has been growing concern among some aviation experts that Reagan administration cuts in FAA inspector ranks are a threat to the industry's outstanding safety record.

The concern is heightened by the fact that new airlines are popping up and old ones are being buffeted by financial turbulence in the competitive shakeout following deregulation of the industry.

"We have not and will not deregulate safety," said Rep. Norman Y. Mineta (D-Calif.), who has scheduled hearings next month on FAA airline inspections after learning the administration plans even more cuts in the next budget round.

Mineta is chairman of the aviation subcomittee of the House Public Works and Transportation Committee.

In April, a Republic flight from Minneapolis to Phoenix carrying 145 persons lost power in both engines and descended perilously close to mountain peaks near Bryce Canyon, Utah, before the crew restarted the engines and landed in Las Vegas. The fuel feed had not been switched from one tank to another, something that should have been done before the first tank ran dry.

In May, a Republic jetliner from Fresno to Phoenix with 86 persons aboard lost one engine and almost ran out of fuel before the crew made an emergency landing at a convenient Air Force base.

The fuel-planning incidents that sparked the extraordinary FAA probe "were not isolated events," the FAA found, according to a report obtained by The Washington Post under the Freedom of Information Act.

"Investigation and interviews determined that there were several other incidents" concerning fuel problems that were caught before they became emergencies, the report said.

As a result of the investigation, Republic has made major changes in management structure, in flight manuals and in crew training programs, according to FAA and Republic officials.

"I have taken the actions I think need to be taken to make sure there is not a repetition of this," Republic President Dan May said.

George W. MacArthur, flight standards manager for the FAA's Great Lakes Region, which is responsible for Minneapolis-based Republic, initiated the special investigation after the second incident. The FAA recommended 21 points to Republic and all but one--unrelated to in-flight safety--have been met, MacArthur said.

Although Republic remains under "continuing special surveillance," MacArthur said he is "very definitely" satisfied that Republic has a safe operation today.

"It looks like the fixes are in," he said. "There is more discipline; there have been some firings and a reorganization."

Republic is one of many U.S. carriers with financial problems. Republic employes recently agreed to a 15 percent pay cut to help the airline through the cash-short winter months.

May said in an interview that there is "no question" that publicity surrounding the two fuel incidents hurt Republic's business. "Everybody had the fear that these are the results of the company's financial condition and somewhere there the company tried to cut corners," May said. "It's absolutely not true."

Republic is a child of deregulation, approved by Congress in 1978. The law made mergers easy, and Republic was created July 1, 1979, when Southern Airlines was merged into North Central. In October, 1980, Republic purchased Hughes Airwest.

Thus, in less than a year, three small regional airlines with different crew training histories, different management philosophies and different flight procedures were joined to become the nation's ninth largest airline. Republic is now a coast-to-coast operation, serving 150 cities and making about 2,800 takeoffs and landings a day.

Republic officials blame many of the crew coordination problems on that rapid integration.

"We had a very good safety record and our general procedure had been to treat pilots as professionals and expect them to perform well, and they did," said May, who came from North Central. " . . . We have come to the conclusion that with an airline as big as we have today we will have to closely monitor cockpit procedures . . . ."

The FAA came to the same conclusion. "The overriding observation within the operations area," its report said, "was the failure of the check-airman program to ensure that the highest professional standards are adhered to."

Check airmen are airline employes delegated by the FAA to certify that pilots and copilots are properly trained and retrained. Much of FAA's safety regulation--in the operation of airlines and manufacture of planes--is by delegation to company employes.

If that were not the case, the FAA would be an enormous bureaucracy of investigators, something administrations of both political parties have rejected over the years. But if company-employed check airmen do not crack the whip, the FAA system breaks down.

FAA's inspectors watch over airlines primarily through spot checks of paperwork and flights. In 1980, the FAA was authorized 640 airline inspectors; in fiscal 1983 just concluded, the authorized number was 534, and the actual number employed in those jobs was 451, according to Walter S. Luffsey, the FAA's associate administrator for aviation standards.

Luffsey said that decrease is partially offset by improved productivity and the fact that a new trend-finding FAA computer will spot airline safety problems and ease inspector workload when it becomes operational late next year.

However, Luffsey said, FAA inspectors were flying in airline cockpits only 10 percent as often in fiscal 1983 as they did in 1980. "My deterrent effort goes down the drain if you release those numbers," he said.

The FAA's MacArthur was asked if budget and personnel cuts had affected his ability to do his job at the Great Lakes Region. There was a long pause.

"We've changed some of our ways of operating," he said. Another pause. "You've put a difficult question on me. I do like my job."

Mineta echoed worries expressed privately by several FAA inspectors interviewed in the field. "Our concern is that fewer ramp checks, fewer inflight checks, less surveillance and less inspectors means less FAA 'presence' in the industry," he said.

The report about Republic's operation is an unusually strong document for FAA writers. It contains one pungent sentence after another describing problems. For example:

* "The majority of crews drew an imaginary line down the center of the cockpit, and each pilot operated his side as he wished. There was little or no coordination on the use of the navigation radios and flight directors, whether enroute or on final approach."

* Checklists, a key to safe aircraft operation, were completed from memory and in some cases, "checklist steps were read but, in fact, not accomplished."

* Six crews encountered weather problems with FAA inspectors on board. "When asked the criteria for using anti-ice, only one crew replied correctly."

* "A breakdown in cockpit management and company check-and-balance systems allowed a potentially catastrophic incident to occur repeatedly within a relatively short period of time."

The inspectors also found that conserving fuel--a major cost factor in airline operations--had become of enormous concern to flight crews. FAA inspectors said that, on most flights they observed from the cockpit, the Republic crews used a fuel-saving flight technique in approaching airports instead of the so-called "stabilized approach" which safety experts recommend.

"When questioned about this," the report said, " . . . three pilots stated that company-employed check pilots 'would raise hell' due to the excessive fuel consumption" of a stabilized approach.

A stabilized approach involves gradual descent to the runway with wing surfaces extended and engines operating at high power. Fuel can be saved by making a higher-angle approach and coasting to the runway surface.

Gramer Foster, Republic's vice president for flight operations, said in an interview, "The feedback on stabilized approach sounds like someone trying to make a weak excuse for having been tabbed. It's been our policy that airplanes will be flown with stabilized approaches."