Those who like their journalism served up happy, contented and unquestioning caress the words "investigative reporting" like a juicy mud pie to be hurled at papers who deliver news unsettling to their digestions.

Fortunately, newspapers still are functioning, by and large, as purveyors of information, gathering it with a healthy skepticism that things are not always as they seem and that some people may seek to manipulate news to serve selfish purposes.

The decision last week by the Pulitzer Prize judges to award their cherished gold medal for public service in journalism to the Fort Worth Star- Telegram for a series, "Teeter Rotor: Deadly Blades," showed that they considered initiative, solid digging and editorial backing worthy of high honor.

The prize resulted from Mark J. Thompson's revealing a design flaw in Army helicopters that cost nearly 250 servicemen their lives. The series led the Army to ground nearly 500 Huey helicopters until they could be modified.

The series also led to vigorous protests from the manufacturer, Bell Helicopters International, Fort Worth's second-biggest company; from the Army and 1,200 indignant readers who canceled their subscriptions. Bell even banned the paper from its premises.

Sigma Delta Chi, a professional journalists' society, also honored the Star-Telegram, noting that the paper had "demonstrated courage in the face of opposition" and saying that the problem had "existed for years without change" until the paper "turned the spotlight on this situation."

Banish investigative reporters? Transform them into docile, wide-eyed business and government groupies?

A Pulitzer for investigative reporting was awarded last week to The Philadelphia Inquirer for an expose of how city police dogs had attacked more than 350 people. Investigation followed William K. Marimow's story, and more than a dozen police officers were removed from the K-9 unit.

The police didn't expose the situation. It was a gutsy newspaper, already subjected to several libel suits by public officials and threatened with a new one as a result of the police-dog story.

Another Pulitzer for investigative reporting went to the St. Petersburg (Fla.) Times and reporters Lucy Morgan and Jack Reed. Their series examining the financial dealings of a county sheriff and several of his deputies led to the sheriff's indictment and removal from office by the voters.

Who told the voters? A pair of reporters and a newspaper carrying out its function professionally and well.

The Sigma Delta Chi award for general reporting by papers with circulation of more than 100,000 went to Dolly Katz of the Detroit Free Press, for a series entitled "Bad Doctors," which documented that government licensing does not ensure protection from inept or unethical doctors. The judges complimented Katz for "remarkable reporting" that "awakened patients and government officials alike to the dangers of bad doctors."

Who alerted the public to the dangers? The medical profession? The state government? No, it was a newspaper with an experienced medical reporter who dug through massive piles of records, talked with the people whose records were involved and demonstrated that the safeguards were shaky.

Life would be a lot easier for journalists if all they had to do each day was to collect official pronouncements, reprint them verbatim, tuck in a flattering picture or two of the potentates and rest secure that the "truth" had been advanced. That's the way it is done in some countries. All such countries need are "journalists" and alert border guards to keep any other views from intervening.

But, as these prize-winning articles have shown, public officials, and even some business executives and professionals, are not always saints and sometimes are revealed as sinners. Readers need to know the unhappy and disquieting facts, too, and thus sometimes depend on journalists who raise embarrassing questions and seek out conflicting views.

If they didn't, the public probably wouldn't know the facts in these prize- winning reports. What you don't know can hurt you -- may even cost you your life, if you're a soldier in a helicopter.