Originally Posted by
Beancountercymru
To SpeedFanatic - it was "A Passion for Flying " by Tom Eeles
Thank you, Beancountercumru!
Well, as I see there is no actual description of how the plane looked like. Tom Eeles just confirmed he saw something unusual because of the sound the aircraft(s) made. There isn't anything about the planform design unfortunately, so we really can't say whether it was triangular shape or not...