I saw a couple of kits for a model airliner that resembled a Boeing 777. I did wonder about the scale when I read on the box that the wingspan was 55 inches.
Several web sites reference the 777 as having a 199' to 200' wingspan.
Assume 200'. That's 2400". Divide by 55. Get 43.6 (approx). That makes roughly 1:44.
So it's just a little larger than an O scale (1:48) model would be, and very roughly twice the size of the most common airplane models (at 1:72).
Andrew