A federal appeals court has reinstated a whistleblower's claim that he was unjustly fired by United Airlines after complaining repeatedly about the company failing to properly perform repair work on U.S. Air Force cargo planes.

A three-judge panel of the U.S. Court of Appeals for the Fourth Circuit overturned a decision by a federal judge to dismiss the retaliation claim. A majority of the appeals court also affirmed the judge's decision to dismiss a False Claims Act claim against United for failure to state a claim.

But the appeals court said there was sufficient evidence to show United did in fact retaliate against David Grant for firing him after he made his complaints.

“Grant's termination, falling close on the heels of his numerous complaints, represents the ultimate action that an employer can take against a reasonable worker for whistle-blowing,” Judge Allyson Duncan wrote for the court.

Judges J. Harvie Wilkinson III and Barbara Keenan joined in that portion of the ruling. Keenan said she would reinstate Grant's FSA claim, saying he presented enough evidence for the case to go to a  jury.

Grant worked for United from 2008 to 2014 at Charleston Air Force Base in South Carolina, according to the opinion. He was a lead aviation maintenance technician who assigned to maintain engines for the locally based fleet of Air Force C-17 Globemaster III cargo planes.

The engines were manufactured by Pratt & Whitney and, according to the ruling, United is the only company in the world with the expertise to properly maintain them.

In his complaint, Grant said he saw United superiors “pencil-whip” through reports saying maintenance work was done when it wasn't not done. He also claimed United workers used the wrong tools and maintenance was performed by United workers who failed to complete eye and training exercises.

United fired Grant on May 6,  2014, after he once again complained to his superiors. He filed his lawsuit in February 2015.

U.S. District Judge David Norton, sitting in Charleston, dismissed the lawsuit on summary judgment. The federal government later intervened in the lawsuit, although it did not participate in the appeal.

Even though the majority agreed with Norton the FCA allegations should be dismissed, it did agree with Grant to some extent.

“Taking the facts alleged as true, it was objectively reasonable for Grant to believe that United had committed fraud,” Duncan said. “Finally, the [complaint] supports a reasonable inference that Grant's actions were designed to stop one or more violations of the FCA.”

Grant's attorney, William Norton of the Mount Pleasant, South Carolina, office of Motley Rice, and United attorney Keith Harrison of the Washington office of Crowell & Moring did not return calls for comment by deadline.