What Airlines or Aircraft did you miss that you will never see again?

I got an idea from Phil's post from the other day. In this one share an aircraft or airline that you tried to photograph and missed and will never have another chance to catch thus haunting you for all eternity.

I'll start off.
I do believe this is the only aircraft that I have ever missed that I tried to photograph.
Chicago-O'hare 1995. Air Canada A320 in the 80s colors (Red and white). When ACA was in livery transition from the red/white cheat line to the (Black tail) colors I didn't know they were they same airline. I said I'll take a pic of it next time. I never had a second chance to get that livery.

Senga

Southwest's NBA livery. Also, when I was in the military, having flight line access to shoot F-16s, F-15s, F-18s, A-10s and c-130s at the base I was at. Sadly, I wasn't into photography back then. The views I could have had were insane.

Trans Caribbean DC-8, Braniff Sky Blue 707-227

Good question...I always coveted a shot of the SCA with a shuttle. That ship obviously sailed, and I've regretted ever since that I didn't fly down to LAX when it came in the last time.

As a native Michigander, I certainly miss seeing those red tailed bowling shoe livery Northwest jets. Granted I was able to get a few terminal shots of them before the repaintings and subsequent merger, but it was before I had the means to get out to DTW for anything beyond a family vacation. Perhaps even worse is the fact that I never got an F-14 in flight, and to say that one will haunt me forever is an understatement.

Iran Air 747SP. I didn't have to knowledge or the ability to commit the time to try to catch it a few years ago, and it hasn't visited since. And as of last week, they are all retired.

I had front row seats to the 31R approach path about a mile from the threshold, from my parents' backyard. I can't tell you how many Eastern jets flew by over the years. Or Flying Tigers. Or, in one of my most salient memories, seeing the Pan Am billboard livery for the 1st time on a 727 and saying to my little kid self, "what the heck did they do that for???"

And not once did I think about picking up a camera. I'm a damn fool. I wouldn't be surprised if that's my dying thought