United will hopefully be going a new direction – Photo: United Airlines

United Airlines’ CEO Jeff Smisek is no longer the CEO. Nor is he even on the board, which he used to chair. It’s a rarity for an airline CEO to make such a grand exit without telegraphing the move to not only the board of directors and shareholders, but even senior management.

There is usually one reason for this. The biggest fear any businessman can face: a federal investigation.