Incident #216 Sighting Report — Chanute Air Force Base, Illinois, 8 December 1948

This document details Incident #216, a report of an unidentified aerial object observed on 8 December 1948 at 18:46 hours at Chanute Air Force Base, Illinois. Two sergeants from the 16th Weather Squadron, both professional weather observers, reported seeing a round, bright white object moving from the northeast toward the south-southwest. The object was estimated to be at an altitude of over 15,000 feet, moving at a speed exceeding 350 MPH, and leaving a white exhaust trail. The observation lasted approximately three seconds. The witnesses described the object as moving upward at a 15 to 20-degree angle. Both observers immediately reported the sighting to the duty forecaster, M Sgt Robert W. Fillman. The report includes formal statements from the witnesses, an 'Essential Elements of Information' form, and correspondence between the 3345th Tech Tng Wg at Chanute AFB and the Air Materiel Command at Wright-Patterson AFB. The official evaluation, extracted from the Project Grudge report, concludes that the object was a 'fairly bright, slow-moving bolide,' noting that the apparent upward movement could be explained by perspective. The investigator noted that the observers were professional weather personnel capable of identifying weather balloons and that the sighting occurred four hours after any scheduled balloon release. The document also includes later correspondence from the Air Weather Service in 1949 regarding the review of incident summaries 173 through 233, which were checked against routine weather-balloon ascents.