Unfortunately, it is:  

And, any _real_ transportation union (with _real_ RLA experience) knows this:

The district court properly determined that Delta's pilots were engaged in an unlawful no-overtime campaign. However, the district court improperly interpreted the gravity and depth of ALPA's duty under the RLA to prevent such an unlawful job action. Because there has been no showing that ALPA lacks control over the pilots, reason dictates that ALPA has not done enough to fulfill its statutorily mandated duty to "maintain" the agreement and avoid an "interruption to commerce." Upon remand, the district court shall issue appropriate injunctive relief directing ALPA to take further steps to end the pilots' no-overtime campaign.

https://law.justia.com/cases/federal/appellate-courts/F3/238/1300/515379/span>

"It is illegal under the Railway Labor Act for airline employees to go on strike without following a complicated set of rules under federal oversight. Even lesser forms of protest, such as widespread efforts to turn down overtime, are against federal rules, McBryde said."

https://www.dallasnews.com/business/local-companies/2019/08/12/american-airlines-wins-trial-over-mechanics-in-work-slowdown-case/

 

"On May 20, 2019, plaintiff initiated this action by filing its complaint. Doc. 1. Plaintiff alleged: To gain leverage in contract negotiations, defendants' members changed their behavior in a concerted fashion by, for example, taking an unusual amount of time to repair aircraft and refusing to work overtime 

https://casetext.com/case/am-airlines-inc-v-transp-workers-union-of-am-1>