Even though one fourth of total flight time must be flown at night, for most Tactical Naval Aviators when the sun goes down its time to shed their speed slacks, splash on a little cologne and head for the O'Club bar. Undoubtedly, there would be a bevy of beauties adorning the barstools this Friday evening at the Jack Black Memorial Officer's Club. After all, it was the day before a huge Drill Weekend for the air station with Navy, Marine Corps, Air Force and Air Guard units all scheduled to be in town for their last drill of 1991. Indeed, the Jackson's ($20 bills) would be flying across the bar tonight.