U.S. District Judge Oren R. Lewis yesterday lambasted federal prosecutors handling the conspiracy retrial of Dr. Murdock Head, telling government lawyers they were "messing up" the case.

The trial's second day was marked by repeated interruptions as the feisty, 79-year-old Lewis pursued his own lines of inquiry. At one point, as David Smith, one of four prosecutors assigned to the case, attempted to regain control in front of the jurors, Lewis growled, "I'll find out. . . . You're getting a little out of hand. You're not doing a good job."

Later, with the jury out of earshot, the outspoken Lewis chided prosecutors: "You had a good case and you're doing a fine job of messing it up."

Head, 59, former director of the Airline Foundation near Warrenton, is accused of conspiring to bribe two former congressmen -- Daniel Flood (D-Pa.) and Otto E. Passman (D-La.) -- with $49,000 in exchange for lucrative federal contracts for his tax-exempt complex.

He also is charged with giving an improper $1,000 gratuity to Flood through former Flood aide Stephen B. Elko. Elko, who was convicted on bribery and perjury charges by a federal court in California in 1977, testified Wednesday for the prosecution.

Head was convicted in October 1979 of one count of conspiracy involving tax infractions in a trial also presided over by Lewis. But an appeals court ordered a new trial, citing errors by Lewis in his instructions to the jury.

Prosecution witnesses yesterday described phony travel expenses, backdated leases and falsified tax returns they said were integral parts of the alleged scheme overseen by Head.

One key witness, Norvel James, a former accountant for Airlie, detailed a system he said was used to create a cash fund for an Airlie affiliate, a filmmaking company called Raven's Hollow, by falsifying travel expenses for employes. Prosecutors contend the cash was used by Head to make bribery payments.

James also testified about a meeting among himself, Head and former Raven's Hollow president Charles Francis in September 1973 when Raven's Hollow had $70,000 of income that was about to be taxed. According to James, Head said: "I would get a $2,000 raise if I took care of Raven's Hollow's taxable situation . . . I got the raise."

But defense attorney Frank W. Dunham Jr. attacked James' credibility, as he had earlier questioned the veracity of Elko -- by referring to previous sworn testimony that he said differed from James' statements yesterday.

Durham also accused James of deliberately failing to place a memorandum in a file that he said explained the nature of the cash fund. Prosecutors allege the fund was used to pay $49,000 in bribes to Flood and Passman through Elko.

Charlotte Fowler, formerly Head's executive assistant, testified that expense reports were inflated to help create the cash fund and that she cleaned the money of fingerprints by wiping it with white gloves.

But Fowler said she could not recall a specific order from Head to clean the money. "I understood it was expected of me," Fowler said, "but I don't remember a specific order." Under cross-examination by defense lawyer Mark Cummings, Fowler also said she did not know where the money went or for what purpose.