The commuter airline pilot realized he had big trouble immediately after takeoff. He could not lower the nose and was in immediate danger of crashing. So he turned around and hollered to some young passengers, "Want to see the takeoff? Run up here!" They did.

With the passengers' weight shifted to the front of the plane, Puerto Rico International Airlines (Prinair) pilot was able to land. The problem was that too much baggage had been loaded in the rear of the plane.

The incident happened in August 1977, according to testimony last week at a National Transportation Safety Board hearing in San Juan. It is one of many incidents involving improperly loaded planes and other problems that underline basic questions about commuter airline safety and the Federal Aviation Administration's willingness and ability to police the burgeoning commuter industry.

In this age of airline deregulation, many persons who fly for work or play are likely to find themselves aboard a commuter airliner. Big-name airlines such as United and American, and smaller ones like Ozark and Piedmont, are pulling out of small and medium-sized cities, leaving commuter lines to fill the gaps.

Many of the commuter airlines are well run and have excellent safety records. Nonetheless, the standard of safety expected of commuters was not as high before deregulation as that expected of major airlines. Congress ordered the Federal Aviation Administration to beef up commuter safety, and new regulations are taking effect this year as commuter traffic increases.

Using statistics that the commuter airline industry thinks are most fair -- accidents per 100,000 takeoffs -- the accident rate for commuter airlines is three times that of their bigger brothers. Using other perfectly valid numbers it is easy to show that commuter accidents occur seven times as often.

Not all incidents aboard commuter flights have happy endings. For example:

On July 24, a Prinair flight took off from St. Croix, Virgin Islands, suddenly pitched upward, then fell to the runway. It was found to be more than 1,000 pounds overweight, and the center of gravity -- the airborne fulcrum on which the airplane must balance -- was 11 inches aft of tolerance because of improperly stowed baggage. Eight persons died.

On March 1, a Universal Airways flight took off from Gulfport-Biloxi Regional Airport in Gulfport, Miss., climbed to about 100 feet, turned sharply right and crashed, killing all eight persons on board. The safety board said the pilot failed to react properly to an emergency that started when the nose baggage door flew open and was hit by a propeller.

On March 10, a Swift Aire Lines flight ditched in Santa Monica Bay shortly after leaving Los Angeles International Airport. Three persons were killed. The safety board said the crew accidentally shut down the good engine after the other engine malfunctioned.

In the first seven months of this year, 48 persons have been killed in 10 accidents involving commuter aircraft. In 1978, five accidents in the same period killed 22 persons.

The safety board's investigations have found instances of improper maintenance, poor pilot training and lax supervision in the most unforgiving form of transportation.

Safety board chairman James B. King said in an interview that "the problem is the commuter accidents we are seeing now are no different from the ones we saw seven or eight years ago. They involve weight and balance questions, maintenance and training.

"We want to create a climate in which safety becomes a very important part of the operation."

King's job is to prod and complain -- the safety board has no regulatory powers. The responsibility for commuter airline safety rests with the FAA.

What has the FAA been doing? It is in the process of imposing tougher regulations on commuter airlines.

The new rules are supposed to insure "to the maximum feasible extent" the level of safety provided by the big airlines. They emphasize the upgrading of training and maintenance, establish minimum management criteria for commuter airline operators and impose more paperwork. Most commuter airlines will be under those new regulations by the end of this year.

"I am confident," FAA Administratior Langhorne M. Bond said in a recent letter to interested parties, "that commuter safety will improve substantially" because of the regulations and stepped-up surveillance.

There are more than 200 commuter airlines flying regular schedules in the United States. They bear such names as Astro Airways Corp., Cochise Airlines and Trans Mountain Air Ltd.

These airlines fly about 1,200 aircraft and have been carrying increasing numbers of people during the last decade. They project a 19 percent rate of growth this year, from 10.1 million passengers in 1978 to more than 12 million.

That growth is encouraged by deregulation, which permits both commuter and major airlines to add or subtract cities from their routes with a minimum of governmental hassle.

The financial pressures on small operators to cut corners to survive stronger competition are regarded as real and disturbing.

On May 30, while the aviation community's attention was riveted on the Chicago DC10 crash that killed 273 persons five days earlier, a Downeast Airlines flight crashed just short of the airport in Rockland, Maine, killing 17. The pilot was making an instrument approach in foggy weather.

Downeast Airlines President Robert L. Stenger was asked at a safety board hearing:

"When an aircraft . . . has to fly to an alternate airport on account of weather, is that an extra expense to the company?"

"Definitely . . . ," he replied.

Several questions later, Stenger was asked if it was Downeast's philosophy that the pilot had the final authority to cancel a flight because of weather.

Stenger replied: "That is the philosophy, yes. But if he -- that's his prerogative. If he wants to cancel the flight due to his discretion, then as far as I'm concerned it better be a legitimate reason, not just because he wants to do it. And [if] everyone else is willing to fly, and other companies are still flying, and he decides not to, then I don't feel that he's using his best judgment to his fullest capacity, either."

The new FAA regulations, according to a number of commuter operators contacted, probably will improve commuter airline safety.

"I would say it is a significant increase [in safety] with the requirement for formality in the [training and maintenance] systems," said Ted Bell, director of operations for Commuter Airlines, which flies between Washington National and Binghamton, N.Y., among other places.

Richard X. Knipe, president of Mall Airways, which connects Albany to New York City area airports, said, "I think we're probably more safe. We have more people. I had to hire a director of maintenance and an operations manager," jobs he did himself before the regulations. "I'm paying them more money than I am myself," he added.

The other central question is whether the FAA is doing a decent job of enforcing its new regulations. The answer to that will not be known for a while, but all the commuter operators contacted said they had seen more FAA people in recent months than they ever wanted to.

The FAA is seeking to add 190 inspectors next year just to help with the extra load imposed by the commuter airlines.

Rep. John J. Burton (D-Calif.), chairman of the House Government Operations transportation subcommittee and a critic of the FAA's Bond, asked him at a recewnt hearing why more people were needed now when none were needed a year earlier.

"I changed my mind," Bond said.