Dr. Murdock Head, the founder and longtime executive director of the Airlie Foundation, was sentenced by a federal judge in Alexandria yesterday to three years imprisonment for participating in a criminal conspiracy.

Judge Oren R. Lewis imposed the prison term on the 55-year-old Head in U.S. District Court after asserting that the evidence against the Airlie founder was overwhelming. The judge also complained that Head had failed to acknowledge his culpability.

Head "made it clear to the probation department that [he believes] he's done nothing wrong," Lewis declared.

Head was initially charged with conspiring to bribe Rep. Daniel J. Flood (D-Pa.) and former Rep. Otto E. Passman (D-La.). But The Washington Post later reported that the jury interpreted the conspiracy count more narrowly and did not believe Head guilty of scheming to bribe either congressman.

The judge said he would not impose a fine on Head because he is "for all pracitical purposes, broke." A financial statement submitted by Head showed that his personal liabilities exceeded his assets by about $126,000. Head's lawyers said he had previously donated more than $1 million to the Airlie Foundation, a conference center and retreat based near Warrenton, Va.

In a brief courtroom statement, Head -- who has also been chairman of the George Washington University department of medical and public affairs -- conceded, "Certainly, I have skated on the thin edge of illegality."

While admitting he had made mistakes in running his Airlie enterprises, however, Head appeared to stop short of acknowledging any criminal wrongdoing. hHis lawyers have announced plans to appeal his conviction. Lewis released Head on a $5,000 personal recongnizance bond until the appeals have been completed.

Head, who holds graduate degrees in law, medicine and dentistry, was convicted by a federal jury on Oct. 12 of a single conspiracy count. The jury acquitted him of two tax-evasion charges, and Judge Lewis later dismissed a third tax-evasion count after the jury reported itself deadlocked on the charge.

The conspiracy count alleged that Head had schemed to bribe Flood, Passman and other government officials and to violate tax laws. The payoffs allegedly included $49,000 in cash.The prosecution contended the money was given to Flood, Passman and former Flood aide Stepen B. Elko, who was a key prosecution witness during Head's trial.

Information obtained by The Washington Post after the jury's verdict was returned showed, however, that the jurors agreed not to rely on Elko's testimony and did not find Head guilty of arranging to bribe the two congressmen. Instead, according to The Post's account, the jurors concluded that Head had conspired to commit tax infractions, including arranging an improper $11,000 loan to a former Internal Revenue Service agent.

The judge took note of The Post's account yesterday, only to describe it as "apparently speculating as to what the jury did." The jurors were permitted to interpret the conspiracy count as they reportedly did under instructions given to them by Lewis.

The 19-year-old Airlie Foundation is situated on more than 1,700 acres of gently rolling farmland in the foothills of the Blue Ridge Mountains, almost 50 miles west of Washington.

The tax-exempt foundation, which describes itself as an "island of thought," provides secluded meeting rooms where government and private organizations hold conferences. Raven's Hollow Ltd., a film-making firm affiliated with Airlie, produces educational motion picture films. The Airlie organizations have received more than $15 million in federal contracts and grants over the years.

After his conviction, Head temporarily stepped aside as executive director of the Airlie Foundation and relinquished his day-to-day duties as a George Washington University professor and department chairman.

In addition to the four counts weighed by jury, nine other bribery and tax-falsification counts aganst Head were previously dismissed or set aside by Judge Lewis. The prosecution has not yet announced what action it plans to take on these charges.

On the conspiracy count, Head had faced a maximum penalty of five years imprisonment and a $10,000 fine. In imposing the three-year prison term, Lewis left open the possibility that he may later agree to reduce Head's sentence. Lewis noted that, if Head's conviction is upheld on appeal, he will still have 120 days to modify Head's sentence after the appeals are completed.

Brain P. Gettings, one of Head's lawyers, had urged Lewis not to sentence Head to prison but, instead, to place him on probation and require him to perform public service work. Federal officials said Head would probably be eligible for parole after about one year's imprisonment if his three-year sentence remains unaltered.

At a brief news conference after his sentencing, Head maintained his seemingly unruffled outlook. Seated beside his son Mark, 25, a George Washington University medical student, Head urged young lawyers and doctors to "actively engage in the political process." Afterward, he remarked, "Given the human condition, the only sustainable posture is one of humor."

Before imposing Head's sentence, Lewis repeatedly challenged Gettings' contention that Head never sought "personal gain" and declared it would be "rather unfair" to treat Head more leniently than a less talented person. Nevertheless, Lewis termed Head's professional achievements "almost phenomenal."