Originally Posted by
Discorde
It was 'PT which had its tail torn off by the Ambassador and was scrapped. 'PI was repaired and returned to service. Both were parked at Hatton Cross for a while. In summer '68 my student vac job was at Air Canada Commissary, located next to the Eagle hangars. The engineers at HC were happy for us to take a look around during lunch breaks. One of the Tridents (can't remember which) had a series of gashes along the trailing edge of one of the wings. The BEA chaps told us it was where one of the Ambassador's spinning props hit the Trident. Sobering experience.
RPT was effectively chopped in half. RPI lost the tail only.
Edit - DUK already answered