Probably one of the most fascinating reports was by an Imperial Airways captain. He his crew and some passengers sighted objects, I think over the Atlantic. He was able to keep the main object in sight for some time and described ‘a feeling of well-being' while near these UFOs.
I saw an old black and white filmed interview of this pilot, and have a report a somewhere about this flight. If no other information is available I'll try to find the copy, though it won't be for a week or so unless I happen across it tonight..