The following is one of the information traced by Jan Aldrich's Project 1947, a private effort to retrieve UFO data and documents around 1947.
In May 1952 a Civil Aeronautics Administration Aviation Safety Agent from Seattle wrote to project Bluebook about a sighting during World War II:
In 1943 I was an Instrument Flying Instructor assigned to the 6th Ferrying Group of the Air Transport Command and based at Long Beach, California. My daily routine consisted of flying four, one hour instructional periods in the morning with a different student for each hour. On one flight while proceeding on the southwest leg of the Long Beach radio range at 5000 feet altitude at the normal cruising airspeed of a BT-13A type trainer, my student and I witnessed an object at this point which to this date defies logical explanation.
This object appeared from the northeast on a level flight path and turned while decelerating from a great speed to fly parallel to us for approximately 30 seconds before it disappeared from view at a slight climbing attitude (5 degrees) bearing to the right across out ship's nose and at speed which I can now estimate to be between 2000 to 5000 miles per hour.
So many years have since passed that it is difficult to reconstruct the appearance of the object but a few prominent facts are still clear and vivid in my mind. They are:
A series of unusual events contributed to the fact that this object made no striking impression on my student and me. There had been a rumor at this time that Lockheed Aircraft Company were building a jet aircraft and we thought we had witnessed the flight of it. I learned much later that the first flight of the Lockheed P-80 did not take place until over a year from this period of time.
Furthermore, I had a camera in the aircraft at this time and although it was hanging on the 'oil dilution' control knob and ready to use, I did not use it for fear of photographing a highly secret aircraft.
I can (remember) telling the student through the intercom: "Come out from under the hood. Lockheed's jet is flying formation with us."
The student pushed back the hood and both of us witnessed the object flying alongside and its flight out of sight. Then the student went back under the hood and the episode was ended. In retrospect, I believe the fact that neither of us at that time attached anything unusual about it must imply that it resembled something which would have encompassed known aerodynamic outlines. Until I first witnessed an early flight of the P-80, I was under this impression. Immediately upon seeing the relative slowness of the P-80 and its easily identifiable outlines, I realized we had witnessed some inexplicable object..."
Apart from the letter he wrote to Project Bluebook, the witness later gave more information. The sighting took place on April 3, 1943 at 09:50 A.M., local time. His Vultee BT-13 took off form the Californian base of the Army Air Force of Long Beach, California. The plane flew at a constant altitude of 4000 feet during 40 minutes, and the visibility was unlimited, the layer of cloud being under them. Casey first noticed the objet because it emitted a bright flash which was very probably a reflection of the sunlight, the object was at this time in the relative direction of the East, in the direction of Mount Santiago. The observation lasted 90 seconds.
Gerry Casey was not simply a pilot, but he was also an aviation writer. This is why he was not inapt to recognize planes, but familiarized with the state of the art of aeronautics. This is also why he heard rumours of the future jet plane.
This case is an example of what Dr. Hynek call "escalation of hypotheses" in extreme slow motion. It was only after the observer saw a jet aircraft that he realized that a conventional answer would not work for his observation.
The writer did not remember the name of the student, but he enclosed a drawing of the object and a list of students who could have been the other witness. The 1952 UFO flap was just starting, but hundreds of letter poured into Project Blue Book. They had no time to even acknowledge the letter let alone investigate what they considered an old case. So they simply filed the letter along with hundreds of others they received on many different subjects in a "catch all" file. They did not include this report as a case file nor did they count it in the Blue Book statistics. - J.L.A.
In his book, Captain Edward Ruppelt who was heading Project Blue Book at that time tells how in May, June, July and August 1952, there were so many investigations to be carried out on UFO reports transmitted by official and reliable channels that his modest group did not even manage to take care of these urgent tasks. He did catch up with a few interesting 1952 cases thereafter, but indeed, there was no chance to do anything about the older cases such as this one, and after his departure of the project, there was no chance that his successors would deal with that, since the new policy was to minimize UFOs and to mention only the cases explained by mundane causes.
It is very unfortunate for the advancement of UFO research: it is absolutely obvious that at the date of the above observation, no aircraft could have even approached the flight behaviour of this object, witnessed and described by observers familiar with aircraft.
There was and there are always UFO sightings for which the observers themselves are convince that they witness some aeronautical technology, advanced for sure, but human, only still secret. The passing of decades reveals thereafter for some of them that the human origin of the observed object is to be excluded. But meanwhile, amnesia and filing in obscure archives does the trick, and without careful work of dedicated people such as Jan Aldrich for example, nothing of all this would be known.