I also log my flights, and I especially enjoy flying on older models such as the DC-9-50s that I first flew with Allegheny Airlines back in 1977. The aircraft you mentioned was the second to last -50 ever built, rolling off the assembly line on Februaty 12, 1980. I don't know how long Delta plans to fly these birds, but any time I get to fly one is like a little trip down memory lane to a time when airlines still offered full service including hot, satisfying meals back in Coach.

As a fellow logger who also takes time to note the registration numbers, you might get a kick out of this trip report I published a couple of years ago.

Happy Contrails!