But the other complaints—the bonuses and the flights—rest on something of a false equivalency. This is the crux of the case. While it's true that the women do get much lower bonuses and tend to fly in a lower class, claiming gender discrimination is an oversimplification.
The men do indeed get bigger bonuses, but unlike the women, they don't draw a full-time salary from U.S. Soccer. The women's national team players are compensated as federation employees, an arrangement replete with benefits. At any given time, at least female 24 players are salaried in a tier system, paying them a base of $122,000, $101,000, or $86,000, depending on what level they are arranged into, per information released in the filing. (At least 18 players must be tier 1 at all times, and all Women's World Cup roster players are tier 1 for that year and the next.)
USWNT players are paid this flat sum—which combines both their national team salary and their federation-funded National Women's Soccer League pay—whether they are called onto the team and make it onto the field or not, so long as they retain their tier designation. Heather O'Reilly, for instance, was cut from the Olympic qualifying team but will remain a tier 1 player for 2016. And these figures don't include performance bonuses, ticket revenue sharing (which is equal to the men's), sponsorship appearances, or marketing and image compensation.
The men, on the other hand, are paid entirely in bonuses, which are larger. The women each get $75,000 for winning the World Cup or the Olympics, plus their share of the FIFA prize money, whereas the men got a multiple of that just for reaching the round of 16 at the 2014 World Cup. The men are only paid if they are called up, make appearances, and win games.
This means that, in reality, the earnings are much more equitable than they seem by merely laying bonuses side by side. According to a 2014 tax filing, Clint Dempsey, Geoff Cameron, Jozy Altidore, Tim Howard, and Jermaine Jones each made around $400,000. That's more than any woman, but that was in a World Cup year.
In the last Olympic year, 2012, Christie Rampone, Becky Sauerbrunn, and Alex Morgan were the top women earners at $275,000—more than any man that year. Incomes for 2015 haven't been made public yet, but one person familiar with the numbers estimates that the majority of the Women's World Cup squad will have cleared over $300,000, buttressed in part by the $1.8 million cumulative Victory Tour bonus, which is augmented by a cut of gate receipts. Certainly, that's still less than many men got in a World Cup year, but the women's earnings are more constant over the four-year cycle and less dependent on performance. The men, on the other hand, have a bumper year every four years, with much lower figures at other times and nothing at all if they're not called in.
As for the flights, they, too, require some context to fully understand. There is no disputing that the men have better travel conditions set out in their CBA, but they also tend to travel further. Historically and presently, a large part of the men's national team plays its club soccer in Europe, whereas the women are almost all employed stateside. That's why for their longer flights, men tend to fly in business class—although not always. For longer team trips, planes are often chartered.
The women are usually restricted to premium economy seats, with extra legroom, but also tend to fly shorter distances. From U.S. Soccer's standpoint, this is a matter of enabling performance. And the women's (disputed) CBA does lay out that players will use business class or a charter for Women's World Cup games and qualifiers that require more than three hours of flying. According to the source, the federation feels like it's been generous with upgrading the women when it has deemed it beneficial to their performance, even when the CBA doesn't require it.