It wasn’t that long ago that Southwest’s self-proclaimed identity as the Love Airline was a credible bit of branding, reflecting a virtuous circle of contentment among the airline’s customers, employees, and shareholders. For now, however, the love fest appears to be over.

Last week, the directors of the Southwest Airlines Pilots’ Association, which represents the airline’s 8,300 pilots, passed by 20-0 a no-confidence vote in the airline’s top two managers, CEO Gary Kelly and COO Mike Van de Ven. According to the Association’s news release, “SWAPA believes it is time for new leadership in order to propel this company forward.”

No love lost there.

A similar no-confidence vote was taken by the union representing Southwest’s mechanics.

The pilots accuse the airline of abandoning Southwest’s customer-focused culture under pressure from Wall Street to boost financial performance. “Senior executives at Southwest Airlines have prioritized short-term stock performance at the expense of long-term investment in people and infrastructure, resulting in the highest level of labor strife and dissatisfaction among frontline employees in the history of Southwest Airlines.”

As evidence of the airline’s failure to invest in infrastructure, the pilots cited a series of systems meltdowns, including last month’s computer failure that resulted in several days’ worth of delayed and cancelled flights, affecting thousands of flyers.

Southwest has dismissed the pilots’ complaints as a bargaining ploy to secure better working conditions and compensation in contract negotiations that have been ongoing for four years.

Whatever the pilots’ motivation, this very public dispute between the airline’s management and two of its key labor groups is a sign that Southwest’s long history of cordial labor relations is over, at least for now. To the extent that the airline’s happy, motivated employees have been key to Southwest’s popularity with its customers, travelers should be worried.

Reader Reality Check

Have you noticed a recent change in attitude among Southwest’s employees?

After 20 years working in the travel industry, and almost that long writing about it, Tim Winship knows a thing or two about travel. Follow him on Twitter @twinship.

This article first appeared on SmarterTravel.com, where Tim is Editor-at-Large.