McCain's campaign plane: a 737, not a 747

I caught a typographical error in Chicago Tribune reporter Jill Zuckman's missive from Sen. McCain's campaign plane yesterday, Election Day:

----- Original Message -----
From: Kenneth Salkover
To: Zuckman, Jill
Sent: Wed Nov 05 11:58:57 2008
Subject: McCain's plane a 737

Ken Salkover
Chicago

Ms. Zuckman:

In the "Swamp" blog version of your story aboard the McCain campaign
airplane yesterday, you referred to it as a 747. Was that a typo?
Air Force One is a B747-400, and any aircraft in the 747 series would
be almost as large. I was pretty sure that was incorrect, so I looked
around and found this article, about the launch of McCain's B737 in
June: http://www.nytimes.com/2008/06/29/us/politics/29plane.html?ref=politics

I follow passenger aircraft as a hobby, so this is of great interest
to me. BTW, a B737 has two engines, and a B747 has four, plus an
enlarged widebody fuselage with a telltale upper-deck hump.

I hope Sen. McCain didn't wear you out over the final days and that
you're ready for your next assignment. Good luck!

-----------
Her reply:

Thanks, Ken - good catch. That was a typo. Appreciate the note.

Jill