Southwest is under pressure to make big changes to its planes, flights, and bag rules: Here's what they could all look like

• An activist investor has bought a big stake in Southwest Airlines and is asking for major changes.
• Elliott Management wants a new CEO and a total review of Southwest's business model.
• The hedge fund wants to fix outdated systems and has suggested more add-on fees to increase revenue.

Activist firm Elliott Investment Management has taken a $1.9 billion stake in Southwest Airlines and has proposed big changes — including a new CEO — to shore up the company's stock price and fix what it's called mismanagement.