Free (or non-revenue) flights have long been a prime motivator for airline employees, and have served as a comfort through recent tribulations such as heavy pay cuts, decreased pensions, longer hours, and the constant specter of layoffs. However, a variety of internal factors have made these flights tougher for employees to get, and less useful even when obtained.
See "Airline Workers Are Left at Gate, Mourning a Perk", Jeff Bailey, The New York Times, March 20, 2006