“Time to spare? Go by air.” (aviation saying)

Early aviation had so many weather and mechanical delays that someone thought up a popular saying—“Time to spare? Go by air.” “Small wonder his theme song is ‘with time to spare, go by air’” was cited in print in an “Airport Activities” newspaper column from September 1945. The old saying is still used whenever airport delays occur.
 
An additional line was added by at least the 1990s—“More time yet? Go by jet.”
 
 
10 September 1945, The Evening Observer (Dunkirk, NY), “Airport Activities” by Kathleen Koepnick, pg. 9, col. 3:
Small wonder his theme song is “with time to spare, go by air.”
 
Google Books
18 November 1946, Life magazine, “Travelers’ Travail” (editorial), pg. 28, col. 1:
Otherwise they will never live down that new slogan, “If you have time to spare, go by air.” Pullmans are full of disgruntled former airline customers.
 
7 January 1951, Morning Advocate (Baton Rouge, LA), “Airborne” by Arthur Folse, Magazine, pg. 6, col. 3:
Remember back 20 years ago when the passenger fatality rate in commercial aviation was so high that slogans like these were common sayings—“If you must be there, on time, catch the train” or “If you have time to spare, go by air”?
 
Google News Archive
26 July 1951, Stanstead (Quebec) Journal, “Rotarians Meet Geographers,” pg. 1, col. 6:
‘There is air service to the arctic, and to most people that is the way to go. There is a saying, however, that goes ‘If you have time to spare, go by air,’ and that is often correct. Air line connections and weather often make a five hour trip take five weeks.”
   
Google Groups: rec.aviation,student
Three useless things to a pilot
Greg Clark
3/16/97
(...)
If you’ve got time to spare, go by air.
(More time yet? Go by jet.)
 
Google Books
The Killing Zone:
How & Why Pilots Die

By Paul Craig
New York, NY: McGraw Hill Professional
2000
Pg. 46:
He says, “If you have time to spare—go by air.” He means don’t ever place yourself in a situation where you must get somewhere and then try to use an airplane to cut down the travel time. You must build in spare time because if the weather gets bad you must wait.
   
Forbes
11/20/2003 @ 7:00AM
The Future Of Personal Aviation
By Rich Karlgaard
(...)
But I realized that flying a small plane has limited utility. There is a saying among small-plane pilots that can be lifesaving: “Time to spare, go by air.”
   
CBS News
Flight Prompts Calls for Passenger Rights
By CBSNews
August 11, 2009, 2:11 PM
(...)
COMMENTS
Old-Warrior says:I’m an old warrior, emphasis on the old. When I started people used to get dressed up to travel. Many times planes were delayed for hours. That was part of air-travel. The old saying was, “Time to spare - go by air, more time yet - go by jet.” Fares were expensive.
   
Google Books
The Flight Level Chronicles:
Interesting People, Unique Places, and a Special Airplane

By Lillian J. Leblanc
CreateSpace Independent Publishing Platform
2011
Pg. 40:
There’s a tongue-in-cheek adage in aviation: “time to spare, go by air.” The uninitiated may find the statement contradictory, since people fly to reach destinations faster than they might otherwise. Some days, though, that just doesn’t happen.