Federal officials who want to fly first class must show in writing that there are "exceptional circumstances . . . essential to the successful performance of an agency mission." This has led to some interesting explanations on government travel vouchers.

One voucher submitted by then-Deputy Transportation Secretary Darrell M. Trent explained his $3,219 first-class ticket from Washington to Paris by saying: "Coach class would not have enabled him to reach his destination on time."

Trent conceded that his first-class seat didn't get him to Paris any sooner than the rest of the plane, but said he wanted to sleep on the overnight flight before a long negotiating session.

Carlos C. Campbell, head of the Economic Development Administration, offered a somewhat longer explanation for why he went first class on a round-trip flight to Atlanta:

"First class necessary as traveler will be accompanying the general counsel who will be traveling first class, both of whom will be making presentations at the National Bar Association's annual conference. Traveler and the general counsel must compare notes on their personal views and experiences in minority business and economic development to avoid duplication in their scheduled presentations.

"Because of respective workloads and scheduled meetings prior to travel, it was not possible for traveler and the general counsel to confer at length relating to their presentations. Air first class on return necessary as traveler will assist the general counsel in recording interpretations on feedback from attendees and answers to possible questions which might arise as a result of the presentation."