While both carriers are in the midst of rough patches, Southwest faces the rougher road as the Federal Aviation Administration this week confirmed it is investigating the airline after multiple close calls and other safety-related incidents this year.

“They absolutely did not need that,” David Vernon, a senior analyst at Bernstein Research, told Fortune. “It’s hard to go out and have your entire management team talk to investors about how much money you want to make in the future when the FAA is conducting an audit on something like safety.”

Both carriers already slashed their revenue outlook during the quarter. Consensus estimates now have Southwest’s diluted earnings per share at $0.51, down from $1.09 in the same quarter last year. That number is $1.06 for American, well below the $1.15-$1.45 guidance provided earlier by the company.

Southwest and American shares have dropped nearly 50% and 70%, respectively, over the last five years. Both airlines posted losses last quarter, slightly missing revenue and earnings expectations. According to Bloomberg, options trading implies American’s stock could move 7.8% in either direction after its call, scheduled before market open. That number is 5.6% for Southwest, which reports midday.

On Wednesday, Southwest shares were trading below the $27 mark, down from an all-time high of $66.29 in 2018. American’s stock price sat just above the $10 threshold, a drop from its all-time high (at close) of $59.34 in 2006.

Southwest and American face strategy concerns

Southwest has long won cost-conscious customers by not charging for things like checked bags or changes to reservations. As rivals like United and Delta tout additional revenues from premium seating like business class, however, Southwest has said it’s rethinking its single-class, open-seating cabins.

As JetBlue founder David Neeleman recently said at Fortune’s Brainstorm Tech 2024 conference, consumers no longer appear willing to battle in the cabin for seats. Activist firm Elliot Management, however, wants to make Southwest look more like ultra-low-cost carriers such as Spirit and Frontier. Calling for the removal of chairman Gary Kelly and CEO Bob Jordan, Elliot announced it had taken an 11% stake in Southwest in June, provoking a “poison pill” shareholder rights plan from the airline.

Most airlines generate nearly 2% of their revenue from bag fees alone, according to a recent report from Barclays, which said the market had evolved past Southwest’s “dated” low-cost, low-fare strategy.

Others, however, worry the types of changes pushed by Elliot could offend loyal customers and undermine its storied brand. Change the business model, Vernon said, and Southwest could struggle to distinguish itself, particularly without a hub network that rivals major carriers like United, Delta and American.

“They’re a relatively unique animal,” Vernon said. “Trying to make them become like all the other animals in the prairie,” he added, could be more trouble than it’s worth.

At American, meanwhile, investors will look for clarity after corporate clients and travel agencies balked at Raja’s “modern retailing” strategy, which pushed customers to buy directly through American’s website or app. After the plan was abandoned, investors will not just want to see how it damaged revenues, Bank of America senior analyst Andrew Didora told Fortune. They’ll also listen for concrete thoughts on how the company is rebooting its sales strategy, not to mention an update on the search for a new CCO.

The rebuild is especially significant as airlines cut back on flights after capacity exceeded record demand, weighing heavily on industry profits.

“They’re going to have a headwind other airlines don’t have in the back half of the year,” Vernon said of American.

At least CEO Robert Isom doesn’t have to look far to see it can be much worse.