Yeah, I don't know whats the problem with the link - it usually works
Anyway, 1:1 crop from that picture:
Maybe your shot isn't ultra sharp because at that distance there's already a little bit of fog or heat haze? And isn't the focus on the winglet instead of fuselage? Or maybe I just got lucky and my sample is little better?
There is nothing better that a good prime lens! I'm a photographer too - but I shoot something a little slower and a little heavier - namely trains
Steam or modern?
I collected a lot of primes and zooms I couldn't afford when I was young. But now they are too many So I started to sort out by • adjusting front- or back-focus und then • shooting a "Siemensstern" through all stops. Taking the best jpeg compression possible one only has to compare the file sizes: the bigger the sharper.