Isley, Lloyd M., Air Force Form 117 (AF-117), Sighting of Unidentified Phenomena Questionnaire, 28 October 1968, 7, 9. Also: Isley 2001, 8-9. In his AF-117, Isley notes the sighting time as 12:30 until 4:30 a.m., and the length of time the phenomenon was in sight as “3 1/2 to 4 hours” based on “the length of time we were on N-7” (1, 3). Isley’s sighting time is inaccurate by 2 hours. In addition, the observation time at N-7 is too long and would be about one hour (3:00-4:02). The total length of time the phenomenon was in sight would be 2:30-4:02. For a discussion of this with Isley, see: Isley 2001, 10-11.