That's the sound of the prop-driven XF-84H, and it brought grown men to their knees. It didn't fly all that great either.
- By Stephan Wilkinson
- Air & Space magazine, July 2003
Edwards Air Force Base History Office
(Page 4 of 5)
Beaird says the starting procedure consumed half an hour: building up hydraulic pressures, establishing nominal electric power levels, and getting the proper green lights.
The driveshaft had high levels of vibration in flight, Beaird says. “It was very sensitive. If it got to where the vibration was so bad that I thought it was going to cause damage, they just left it up to me to decide whether to get out of the airplane”—he means eject, which he never did, but 10 of his 11 flights ended in premature or emergency landings due to vibration or prop-controller problems. “The only time it became a handful was when you got it out around 400 knots,” he says. “The propeller governor [which controlled rotational speed] would start surging, and the airplane would roll rather violently.” The entire airframe was trying to rotate around the propshaft, torquing like a big flywheel with wings.
The late Lin Hendrix, a Republic test pilot who made a single Thunderscreech flight and was the only pilot to fly the second of the two airplanes, wrote in the August 1977 issue of the British magazine Aeroplane Monthly that Beaird, “who never swore, once said after an emergency landing, ‘By jingo, that airplane is going to hurt somebody!’ ” Hendrix himself declined further opportunities to fly the ’Screech, telling Republic’s chief engineer, Jim Rust, a muscular six-foot-four and 235 pounds, “You aren’t big enough and there aren’t enough of you to get me in that thing again.”
Only a single XF-84H survives, the number-two airplane having been junked. The original test bed spent several decades at the entrance to Meadows Field, the Bakersfield, California municipal airport, where an electric motor in the spinner turned the prop at a stately 10 rpm, hardly hinting at the ’Screech in full song. In 1992, the old gate guardian got hangar space at the U.S. Air Force Museum in Dayton, Ohio. It has since been restored to display condition, and about a year ago was finally put on exhibit in the museum’s experimental-aircraft hangar.
Robert Schneider and Darrell Larkin had both flown F-84s in the Ohio Air National Guard, and they assembled a team of volunteers who spent a total of 3,710 hours on the restoration. “You know you’re in trouble when you have to have pilots working on an airplane,” Schneider says, laughing, “but Darrell and I found a lot of retired chief master sergeants who’d been sheet metal guys and had other specialties. They’re the ones who really did the work.”
Aside from the supersonic-prop experiment, F-84s served as test bed aircraft for a considerable variety of other oddball projects. Schneider lists some of the reasons why: “It had a roomier cockpit than the F-86, and there were a lot of them made,” he says. “It was a good-flying aircraft—a little underpowered but extremely strong. I had a midair collision once with another F-84, and we both kept flying and landed safely.” A careless ground controller vectored Schneider and a flight of three other F-84s into a thunderstorm, and in the murk, the -84 to his right slammed into Schneider’s airplane, its stabilator shearing off the front of his wing tank and then whacking the fuselage.
“The XF-84H was a hulk when we got it,” Darrell Larkin says. “I think every kid who ever walked by that airplane in Bakersfield threw a rock up the tailpipe. I had to take a ton of stones out of there.” But otherwise the airplane had never been vandalized, probably because it was on airport property and reasonably secure. “Except for the birds and other animals—prairie dogs, I don’t know what,” Larkin says. “There were nests everywhere. We had to do a lot of vacuuming, clean up a lot of dirt.”
Its stubby but strident propeller got all the attention, but the XF-84H set some other precedents. The ’Screech was—and still is—the world’s only turboprop with an afterburner, and visitors to the Air Force Museum can peek into the tailpipe and see all the spray bars and plumbing still in place.