Bought Colgan, almost had to shut it down in May 08 because it was losing so much money. Bought Mesaba on credit and misjudged the parking schedule then misjudged the time it would take to train pilots. Bought building space downtown he couldnt hope to afford, basically an ego buy. Never integrated the company from a back of the house perspective, MX was sabatoged as a result. Hid the losses and overestimated the income for years which led the investors (owners) to try and sieze and liquidate company. Made the suicidal decision to operate two companies on one list with a operational fence between them. Pushed for every at cost contract he could sign to get his foot in the door and could never follow through with the service promised, over promise and under deliever. Oversaw and fostered the laziest managment group ever hired who couldnt be bothered to even input pilots training records or learn how to use the pay software which led to picketing as well as a world of bad press. To be clear, payroll was clueless how to use the software, they spent months manually editing instead of coding correctly.
Thats a couple I can think of, feel free to contribute everyone.