Why was the Voyager aircraft not symmetrical?

A 20-year mystery solved.

Voyager ends its round-the-world trip in December 1986.
Voyager ends its round-the-world trip in December 1986. Joe Pappalardo

Some people are really bothered by things that are unequal.

This time it was a portion of Voyager, which in 1986 completed the first nonstop, non-refueled flight around the world.

Reader Peter Lakatos has been torturing himself for 20 years over the puzzle of why the canard-like structure near Voyager's nose (a canard is a horizontal stabilizer mounted in front of the main wing) joins the twin booms at different points. He noticed this both in photos and in museum scale models, where one of the booms juts out slightly ahead of the other one.

Thus begins the case of the uneven booms.

"On the left side the leading edge of the canard is exactly flush with the forward-most point on the boom," Lakatos wrote us. "That is not the case on the right side, where the canard's junction with the boom is noticeably set farther back from the tip of the boom."

There's a good reason for that, says Pete D'Anna, a volunteer and retired aero-electrical engineer who works with Voyager at its home in the National Air and Space Museum. It doesn't have to do with the canards themselves, but with a reconfiguring of the aircraft's sensors during Voyager's design phase. The starboard (right side) boom had to be extended slightly forward of the canard to house radar antennas for navigation and weather, he explains.

The sensors were originally mounted inside the cockpit. But, says D'Anna, the designers, Burt and Dick Rutan, discovered that in that location, the radar encountered major interference from Voyager's alternator. "They solved that by moving the antenna out to the forward part of the right hand boom," D'Anna says.

According to pilot Dick Rutan's 1987 book Voyager, "We had to hack up the wing, dig a big trench to run a cable through, then fill it up and fair off a bubble on top of the boom." D'Anna surmises that they had to extend the tip another foot or so to fit both antennas. "When you look at the airplane as it is displayed at the museum, you can see the antennas in the tip," he adds.

After 20 years, Lakatos is happy to have his answer. "That's one option I hadn't considered, which punctuates the old saying about missing what should be apparent," he says, providing as good a capstone to this case as I ever could.

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