The airline mandated the training for pilots who ordered additional fuel on some flights across the Atlantic, News Channel 14 in Raleigh, N.C., reported.

"It's extracurricular … it's not required and what they're trying to do is intimidate our captains," said James Ray, spokesman for the U.S. Airline Pilots Association.

"Cutting peanuts off the aircraft is one thing but taking necessary fuel off the aircraft is a completely different issue," Ray said.

Failure to complete the training could result in the Federal Aviation Administration revoking a pilots' flying license, Ray said.

The airline denied the training was punitive or compromised safety.

"All pilots go through this training," US Airways spokeswoman Michelle Mohr told News Channel 14. "We, of course, are not instructing pilots to ever make a decision that could even remotely compromise the safe operation of the aircraft."