Oct 28 (Reuters) - Southwest Airlines ( LUV ) must face

a lawsuit accusing the carrier of illegally intimidating and

disciplining pilots who participate in its more than

9,000-member pilots union, a federal appeals court ruled on

Monday.

In a 3-0 decision, the 5th U.S. Circuit Court of Appeals

said the Southwest Airlines Pilots Association sufficiently

pleaded that the Dallas-based carrier had "anti-union animus" to

allow the dispute to proceed in federal court.

A lower court judge had ruled that the dispute was

minor, and therefore belonged in arbitration.

The case stemmed from Southwest's ( LUV ) decision to strip

Timothy Roebling of his responsibilities and pay as a "check

pilot," a special group of about 300 pilots who work closely

with management and train other pilots.

Southwest ( LUV ) ostensibly cited Roebling's use of a vulgarity

to justify the discipline, but the union said it resulted from

his decision to join the union's check pilot committee.

Writing for the New Orleans-based appeals court panel,

Chief Judge Jennifer Walker Elrod agreed with the lower court

judge that the dispute was a minor matter under the federal

Railway Labor Act.

But she said accusations that Southwest ( LUV ) made check

pilots fearful of retaliation for association with the union,

and that Roebling's boss threatened to strip him of his

qualifications, made this case different.

These kinds of allegations "sufficiently support the

union's claim that Southwest ( LUV ) intended to 'weaken' or 'destroy'

the operational capacity of the union," she wrote.

Southwest ( LUV ) had no immediate comment. Lawyers for the

union did not immediately respond to requests for comment.

The appeals court returned the case to U.S. District

Judge Barbara Lynn of the Dallas federal court, who had

dismissed it in September 2023.

The case is Southwest Airlines Pilots Association v

Southwest Airlines Co ( LUV ), 5th U.S. Circuit Court of Appeals, No.

23-11065.