Inventive design or fatal flaw? On a homebuilt airplane, one person makes the call.
- By Sarah Brown
- Air & Space magazine, January 2013
Courtesy Jon Ross
(Page 2 of 3)
Thomas is qualified to inspect experimental amateur-built airplanes, as well as both kitbuilt and factory-built light sport aircraft; he has done the initial airworthiness inspection for about 170 airplanes. About 45 of them have been light sport, he says, including a tube-and-fabric Sky Ranger that Schupp built in 2003. Schupp’s work had been meticulous then, but a DAR takes nothing for granted.
When forgetting a two-cent cotter pin can bring down a $70,000 airplane, neither builder nor inspector can afford to make assumptions. On Halloween 2006, a Jahns RV-7, a type similar to Schupp’s, took off from Monmouth Executive Airport in New Jersey on its first flight, the DAR at the controls. The airplane performed a series of steep turns without incident and made a pass over the runway before the throttle linkage came loose. The pilot could not accelerate. The builder watched as the airplane turned back to land, slowed, and entered a stall. The nose dropped to the ground. The landing gear crumpled. The airplane came to a halt so quickly the rudder was kinked. But the test pilot stepped out unscathed.
The DAR (whose name is not given in the accident report) had checked on the project prior to the inspection, he explained, and had told the builder during his last visit to fix a part of the throttle linkage. When he arrived in his role as DAR, the lower cowling covered the linkage. Because he considered its removal “disassembly,” not allowed if a builder provided records of in-process inspections, he left the cover in place. If he had removed it, he would have seen that the builder had forgotten either to insert or to bend the inch-long pin securing the nut. When it came loose, nearly seven years of work slammed into the ground.
Schupp purchased his first kit for the RV-9A on May 20, 2004. He didn’t build the aircraft all in one stretch, but he built it: Photographs documented the process, from the arrival of boxes to Schupp wielding a rivet gun. The images would help convince Thomas that Schupp completed the majority of the work himself—a requirement known as the 51 percent rule. As long as the builder completes the major portion of the work, he can enlist help. But if more than 49 percent of the labor is farmed out—for instance, to a company that sells airplane kits—the builder cannot qualify for an experimental airworthiness certificate, which is reserved, in the FAA’s language, for “persons who undertook the construction project solely for their own education or recreation.” Ross, who finished an RV-8 in 2004, says he employs legendary kitplane designer Burt Rutan’s “seven-minute rule.” “If anyone comes in and they want to chat, I’ll spend seven minutes with them and then put them to work,” Ross says.
Many builders solicit help more formally from volunteer builders, restorers, and mechanics in EAA’s technical counselor program. DARs with homebuilding experience usually also are technical counselors. Some, like Joe Gauthier of Connecticut, swear by the program. If a project is within a 50-mile radius, he wants to see it as a technical counselor before he inspects it as a DAR. It gives him a chance to provide guidance early in a way he can’t as a DAR and gives the builder a sense of what he’ll be looking for. “By the time I get there with my DAR hat on, most of the issues are resolved,” he says.
Thomas is also a technical counselor, but when he’s counseling he doesn’t volunteer that he’s a DAR: He doesn’t want builders to be nervous about the final inspection when he’s trying to help them, he says. Proudly five-foot-four, he’s not physically intimidating, and he likes it that way: He’s Bobby, not James or Robert.
Builders are often smiling when the DAR arrives, and Schupp had reason to be confident: Members of his EAA chapter had looked over his RV many times, he says, and a technical counselor had visited after each major stage of construction: empennage, wings, fuselage, and engine. He even ran through his own inspection checklist, examining the airplane from spinner to tail, he says. But there’s always a chance the DAR could catch something the builder missed.
“Any time you have someone looking over your work…you get very protective of it,” Schupp says. But he was counting on Thomas’ fresh eyes to keep him safe when he taxied out to the runway and opened the throttle.
Thomas laid a folder of FAA forms and checklists, all in duplicate, on the table. Meticulous record-keeping helps the DAR protect himself in the event of an accident. “The wing could fall off the airplane, but if it didn’t have a builder’s log, that’s the problem,” Thomas later quipped as he photographed Schupp’s builder’s log. He fanned out photographs of the various stages of construction and took another picture for extra proof.
The FAA provides a list of minimum requirements for an inspection, but each DAR has an area of special concern. Thomas’ is fuel flow. He won’t even look at an airplane until he has the flow data. (He’s not alone in his attention to the fuel system: Frank Sperandeo, an Arkansas-based DAR, says he makes his clients flush the system five times before he inspects it.)
Lying on his back on the concrete, New Balance sneakers jutting out from under the fuselage, Thomas checked the throttle linkage as Schupp opened and closed the throttle from the cockpit. Mixture, throttle, carburetor were all in working order, but Thomas suggested Schupp add a transmission screen to keep insects from crawling in. “Bugs have put more than a few people in the ground,” he says. If spiders crawl in and keep gas from making it to the engine, you’ll have just enough in the fuel lines to get 150 feet off the ground, he says—too high to have much runway left, too low to turn back.