Originally Posted by
Discorde
Alternatively the 'X' merely cancelled the 'C' (commercial?) when the registration system changed from 'NC' to 'N' for all US registered commercial aircraft.
88836 was delivered new to Pan Am in January 1946, their first such aircraft - although not their first in construction number order, and thus very likely to have been used for experimental purposes before delivery. The first non-military Connies of all were delivered to TWA just a few days earlier. The last two digits of this Pan Am batch align with the construction number, 2036, a Pan Am approach on several types of the era. The category letter was ended in January 1949, so it would have spent the first three years as NC.
Is the photo at Burbank ?