In a move that could prove a little embarrassing for the FAA, the agency quickly removed new requirements easing oxygen use in Part 121 operations upon learning that it apparently used inaccurate data to justify the rule. On November 10, the FAA published a “direct” final rule (meaning no NPRM) that changed the flight-level requirement at which the flying pilot must use his oxygen mask if the other pilot leaves the cockpit, from above FL250 to above FL350. The amendment, scheduled to go into effect yesterday, resulted from the FAA’s call in February 2004 for suggestions on eliminating needless regulations, as well as numerous petitions from airlines to increase the altitude. However, shortly after the rule was published, the NTSB said the FAA had “relied on time-of-useful consciousness data that did not represent actual pilot performance under realistic decompression conditions.” Therefore, the Safety Board asked the FAA to withdraw the rule.