Airliner window decals

Depends on the decals.  Some come with the forward and aft doors as part of the windows which really helps align.  Otherwise it's usually an offset from a boot stripe... which I tend to get crooked.  Lots of water and when your sure, stand back or look at it in a mirror. 

I always use the setting solution (not solvent solution) on those except for those from Draw Decals.  The later stretch with setting solution.

Are the ones you have problems with windows along with other stripes and details?  If windows only, that clear window solution works fine on 1:144 size windows as an alternate to decals.

Thanks guys!

Honestly...a Mk. 1 eyeball is the best.  Look from the tail to the nose....and then from the nose to the tail...while the decals are still able to be moved.  Adjust bit by bit until the line of windows is straight.  Then softly blot....let dry a bit...and hit it with softener for the fix.