The U.S. Court of Appeals has ordered new trials in the cases of three Vietnamese orphans who were awarded close to $2 million in damages for injuries suffered in 1975 when a Lockheed C5A transport on a mercy mission from Saigon to the United States crash landed in a Vietnamese rice paddy.

The cases were the first three of about 25 lawsuits to be tried before U.S. District Court judges here on behalf of orphans aboard that aircraft who are now seeking damages from Lockheed for their injuries. In the three cases, all tried before Judge Louis F. Oberdorfer, one orphan was awarded $500,000 and another received $1 million.

In the third case, the jury declined to award any damages. Oberdorfer eventually ordered a second trial in the case and a jury awarded that orphan about $400,000.

In a two-page judgement issued late Monday, the appeals court reversed all three cases and said it would follow up later with a written opinion. The case was heard by Senior Judge David L. Bazelon and Judges Carl McGowan and Roger Robb. In its judgment, the court noted that its decision would affect similar cases still pending in the lower court.

When the appeals court issued its decision, Judge June Green declared a mistrial in the orphan case before her because one of the issues cited by the appeals court directly affected the case. Verdicts have been reached in at least four other cases. Green also postponed another orphan's case that was scheduled for trial Thursday.

The appeals court indicated five areas where Judge Oberdorfer had erred. The appeals court said it intended to elaborate on these issues, which include who should pay some attorney's fees in the cases and whether a statement by an attorney for Lockheed should have been allowed into evidence at the trials.

The appeals court also questioned Oberdorfer's ruling that since two juries had found that the orphans suffered brain damage as a result of the crash. Lockheed could no longer argue that point at later trials.