Originally Posted by
CZAMFlyer
Boeing used to assign internal customer codes that are suffixes to the aircraft type itself. Rather than, say, a 747-400, you might see 747-433. The first '4' indicates it's a -400 series model, and the '33' is the Boeing customer code for AC*. I should say 'was', as Boeing no longer uses customer codes for their 737-Max, 787s and beyond.
Perhaps Bombardier has a similar numbering convention, and their customer code for AC is '63'?
* We all know that AC no longer uses 747-400s, and Lord knows I've been looking in vain for them at YVR lately, but the -433 designation remains, following the planes' transfer to new owners.
.........................or the AC GA was just dreaming stuff up off the top of her head to get people to hurry up, check their luggage, sit back down so she can get back to a Reddit.com discussion or running Gabor Lukacs name through the computer to see when he is through next.