Up in the clouds / Far from the crowds / Below, looming along with a song

Ace Drummond Chapter Eight, ``The Sign In The Sky'', opens with the discovery that Ace Drummond and Comic Relief Mechanic Jerry are not dead.

( Pigeons put in an important appearance not wholly unlike the role they would play in the Edward G Robinson/Nigel Bruce vehicle _A Dispatch From Reuters_; also, they fake me out about a cliffhanger in a way that must have really thrilled them in 1936 and delighted me here.  )

I'm not seeing what sign this was supposed to include.

Trivia: Boeing was originally incorporated as the Pacific Aero Products Company. Source: The Boeing 247: The First Modern Airliner, F Robert van der Linden.

Currently Reading: Fantasy and Science Fiction, May/June 2011, Editor Gordon van Gelder.