Longevity really depends on the industry that said corporate flight department is a part of. Bristol-Myers Squib was a charter member of NBAA and they no longer have a corporate flight department. New CEO's like to come in and "leave their mark" on the company and will shutter a department in order to manipulate an earnings statement to get performance bonuses. On the flip side, certain economic segments i.e. food, utilities, govt contractors tend to have more staying power.