17,909Documents 78Collections 1940–2025Years 25+Countries

Declassified UFO / UAP Document

Incident #31 Sighting Report — Northern Arizona, mid-December 1947

📅 mid-December 1947 📍 Northern Arizona, Route 66 🏛 ATIC 📄 sighting_report
Project GrudgeNorthern Arizona1947aerodynamistvapor trailUAP

Ever wanted to host your own late-night paranormal radio show?

Across the Airwaves · Narrative Sim · Windows · $2.95

You're on the air. Callers bring Mothman, Fresno Nightcrawlers, UFO sightings, reptilian autopsies, and whispers about AATIP and Project Blue Book. Every reply shapes how the night goes.

UFO & UAP Cryptids Paranormal Government Secrets Classified Files High Strangeness Strange Creatures
The night is long. The lines are open →

AI-Generated Summary

TL;DR

A professor and aerodynamist reported an unidentified object in Northern Arizona in December 1947 that left a non-standard vapor trail. The object performed high-speed maneuvers at altitudes between 20,000 and 50,000 feet.

This document contains a sighting report for Incident #31, recorded under Project Grudge. The incident occurred in mid-December 1947 in Northern Arizona, specifically along Route 66. The witness, a professor and aerodynamist from the University of Colorado, observed an object while in flight. The witness reported that they could not see the actual object, but observed a heavy white trail that did not resemble a conventional vapor trail. The object was described as performing vertical and horizontal maneuvers at an estimated speed of 600 mph and an altitude between 20,000 and 50,000 feet. The weather was reported as clear, and there was no sound associated with the object. The report includes a checklist of observations and is indexed in a summary of Dr. Hynek's evaluations of Project Grudge reports, where it is categorized under high probability astronomical events, though the specific report details suggest an unidentified aerial phenomenon.

Object left white heavy trail but it did not look like a regular vapor trail. Could not see actual object

Official Assessment

The observer, identified as a professor and well-known aerodynamist, reported an object in the early morning of mid-December 1947. The object was not visually identified, but left a heavy white trail that the witness noted did not resemble a standard vapor trail. The object performed vertical and horizontal maneuvers at speeds estimated at 600 mph.

Key Persons

Organizations