Burger King.
Easily.
Air travel consists of vacationers and business travelers. Both cut back substantially in a recession. Vacationers take less expensive vacations, typically closer to home. And in a recession, business travelers conduct more of their business via phone, e-mail, Skype, etc. Airlines in general are very susceptible to recessions.
As for Burger King, demand for fast food is far less elastic than air travel. Beyond that (though it's not really true), fast food is viewed as cheap. That makes it more recession-resistant than many types of companies.
Hope that helps.
Which one would you pick and why? which one would perform better in a recession? MSN rates them both a 10 out of 10 for 2014.