They usually are about 6-feet shorter than the
body of the trailer. This takes into account the radius/segmented end caps...the awning only goes on the straight panel portion. Also, keep in mind, the advertised
size of an Airstream trailer is measured tongue to tail,
not the body. And some years/models/lines they sometimes round up and sometimes round down.
If someone has the same model as you are inquiring about they should be able to tell you with more acuracy.
Shari