“If two wrongs don’t make a right, what do two rights make?”/“An airplane.”

A popular aviation riddle about the Wright Brothers is:
 
Q: If two wrongs don’t make a right, what do two rights make?
A: An airplane.
 
The joke has been cited in print since at least 1969.
 
 
Wikipedia: Wright Brothers
The Wright brothers, Orville (August 19, 1871 – January 30, 1948) and Wilbur (April 16, 1867 – May 30, 1912), were two American brothers, inventors, and aviation pioneers who are credited with inventing and building the world’s first successful airplane and making the first controlled, powered and sustained heavier-than-air human flight, on December 17, 1903 four miles south of Kitty Hawk, North Carolina. In 1904-1905 the brothers developed their flying machine into the first practical fixed-wing aircraft. Although not the first to build and fly experimental aircraft, the Wright brothers were the first to invent aircraft controls that made fixed-wing powered flight possible.
     
Google Books
January 1969, Boys’ Life, ‘Think and Grin,” pg. 72, col. 1:
Orville: If two wrongs don’t make a right. What do two rights make?
Wilbur: An airplane? — Jack Juni, Ann Arbor, Mich.
 
22 March 1971, The States-Item (New Orleans, LA), “Jumble” by Henri Arnold and Bob Lee, pg. 26, col. 8:
If two “wrongs” don’t make a “right,” what do two “rights” make?—AN AIRPLANE
     
Google Books
May 1972, Boys’ Life, “Think and Grin,” pg. 82, col. 3:
Orville: Two wrongs don’t make a right.
Wilbur: Then what do two rights make?
Orville: An airplane. — James Slater, Spring Valley, N.Y.
 
Google Books
May 1983, Boys’ Life, ‘Think & Grin,” pg 74, col. 2:
Steve: If two wrongs don’t make a right, what do two rights make?
George: I don’t know. What?
Steve: An airplane. — Eric Dobin, Watchung, N.J.
 
Google Books
March 2002, Boys’ Life, “Think & Grin,” pg. 58, col. 1:
Bill: If two wrongs don’t make a right, what do two Wrights make?
Jill: A wrong?
Bill: Nope, an airplane. — Mark Letts, Newport News, Va,
 
reddit
If two wrongs don’t make a right, what do two rights make? (self.Jokes)
submitted February 16, 2014 by [deleted]
An airplane.
 
reddit
If two wrongs don’t make a right, what do two rights make?” (self.Jokes)
submitted September 14, 2015 by hingle_mcringlebery7
An Airplane