Brilliant, brilliant work on the case! I can't tell you how much I admire that kind of research thoroughness. I don't know if you are interested, but there's a photo of the Centaurus in the Flight International files:
In thinking about the solution, I wondered -- could it be possible that what was seen was actually the 'shadows' of distant clouds projected toward the airliner and distorted by mirages? (www.stormeffects.com)
[Joel CARPENTER is a long-time American researcher with a special interest in photographic and historical aspects of UAP reports. As an avid collector of documentation and photographs on aircraft, spacecraft and missiles, Joel developed a particular interest in the relationship between post WW II experimental aerospace projects and the 'UFO' phenomenon. He holds degrees in history and industrial design and is the author of In the Dark : Secret Weapons, UFOs and the USAF published by Tab Books (Blue Ridge Summit, PA, 1995).]
Our reply (Martin SHOUGH + Wim VAN UTRECHT)
Many thanks! Much appreciated. And the Flight article is fascinating, a real insight into the practicalities of aviation in those days - like the half-joke about providing umbrellas for the crew because "as with all airliners" it rains in the cockpit when frozen condensation thaws during descent! Great stuff and some nice photos.
Actually we found photos of the very plane, G-ALSC Centaurus, and of the cockpit interior of a Stratocruiser (see examples below).
As for the interesting cloud shadows idea: I don't think so because shadows of remote clouds projected on (presumably) an intervening haze could not have the optical contrast required. The target clouds in the mirage theory must be circa 400 miles away to keep relative afterward displacement (relative to the plane) down to an acceptable small figure.
The same would apply to projected cloud shadows: the haze on which the target shadow image is being projected must itself be this far away. (In fact the parallax problem is slightly worsened because as the sun sets it is moving somewhat North below the horizon - to the right - in the same sense as the aircraft and therefore tending if anything to throw cloud shadows increasingly towards the left.) I think cloud silhouettes are a better fit in this case.