'919 was the one allocated to RAE Farnborough so I had several flights in it. Do you know, the RAF insisted on flying it with 4 crew on a flight deck designed for two! ( 2 pilots, FE, Nav)
I remember OC Flying Bedford bringing his 'new' One Eleven - 500 down to Farnborough one day (must have been 432, 433 or 763 can't remember which) and COEF (RAE Commanding Officer Experimental Flying) for some reason took exception and told him his flight wasn't authorised so take it back to Bedford!