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Test Drivers

Behind the glamour boys in X-planes is an entire profession making sure your Cessna has its wings on straight.

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(Continued from page 1)

Perhaps the biggest danger these pilots face is not their untested aircraft but their environment. Piper’s test pilots ply their trade in one of the busiest air corridors in the country, and it is not just the airplanes that get their attention. It’s the feathered creatures who enjoy the same south Florida sunshine and at the same altitude as the pilots. “Let me tell you,” Martinelli says, “if I ingest a bird or something else happens and I lose the engine, I’d rather put it down in the ocean and take my chances with the sharks than go down in the swamps and deal with one of those gators.”

Flying five to seven days a week with an average of five flights per day, production test pilots buzz over a lot of sharks and gators, taking every new airplane to every placarded redline and every minimum flyable whatever. If a twin-engine Seneca is rated to climb at 1,500 feet per minute, they make sure each one does. If the operating manual of a single-engine Archer says the airplane will stall with the gear down at 48 mph, you can be darn sure a Piper pilot has made sure they all stall at 48 mph. By the time the Federal Aviation Administration grants an airplane type a certificate of airworthiness, one or more of Piper’s test pilots will have tested and checked off hundreds of  items in a thick Flight Inspection Report. From confirming that the map light works and the trim wheel has no excess friction to making sure the compass is accurate and the cabin defroster is operational, there is no detail too minute for inspection and approval. And with today’s general aviation instrument panels looking more like that of a Super Hornet than the one in the Spirit of St. Louis, it can take four or more flights to check all the mechanical and electronic gear and get it working as advertised.

Which brings us to 700 bumpy feet over Florida swampland. Little more than 10 minutes ago, Jones was soaring 25,000 feet over the Atlantic making sure maintenance crews had fixed a minor glitch in the pressurization system of a Malibu Mirage, an $869,000 single-engine turboprop. Now he’s taking the airplane down among the gators, water moccasins, and buzzards, going flat-out through turbulent air, doing a test the Flight Inspection Report for Model PA46-350P calls “maximum indicated level flight airspeed.” “We run at full power at low altitude to check performance,” Jones says. “If you’ve got good rpm, good fuel flow, and good manifold pressure and you are not flying within a certain known speed range, something is wrong somewhere. Could be airframe-related. A prop could be dragging. Something with a landing gear door. At that point you really do not know what, but you do know you cannot check it off as acceptable.”

A production test pilot taking an airplane on its first flight will always be able to find something that can be tweaked. This particular Malibu has been up three times, with mechanics adjusting a list of ailments in between. Now, with the airspeed indicator reading a right-on-the-money 183 knots, Jones makes one final, satisfied squiggle of his pen and closes the book on the last open question about the Malibu. Of the event, Jones offers no memorable words. Not even a high-five. As he steers for home a couple of buzzards zing past our wingtip. Jones just smiles. “Our competition,” he says.

Upon landing, Jones walks away from this three-quarter-million-dollar machine, which he has taken from the cradle to certified-for-delivery. He will likely never fly the airplane again, or even see it. But there are two other Malibus waiting for first flights, a Seneca that needs its global positioning system re-checked, a couple of Archers that need some tweaking, and a factory cranking out more just behind them. It keeps him busy, and it keeps him flying.

As much flying as Jones and Piper’s other production test pilots logged—well over 7,000 hours each—they could never come close to the king of production flight test. The king does not live in sunny Vero Beach. He lives in landlocked Wichita, Kansas, and is now retired. And does he have some hangar stories…

“Here is one,” the 92-year old Mort Brown begins. “In the ’60s we were building the Cessna 337 and they flew fine. But then they decided to change the wing and I soon noticed handling problems with the planes I was flying.”

Brown, at the time Cessna’s chief of production test pilots, kept bringing one of the particularly ill-performing twin-tandem-engine 337 Skymasters back from test flights with a bad report card. It was apparently a frustration Cessna’s production manager did not need. After all, it was the production manager’s job to make certain the “production” made money for the company. Yet here was Brown bringing back an airplane again and again, complaining about its flying characteristics. Finally, the production manager decided to tell Brown what was what, explaining in no uncertain terms that there was not a thing wrong with the 337, that engineering had signed off on the new wing and Brown, as a production test pilot, was obligated to sign off on the airplane. Or perhaps find another line of work.

“So I said, ‘Okay, boy, let’s go for a ride,’ ” Brown recalls. “I got us up to 8,000 feet, and sure enough, when I put it into a gentle stall, we rolled up into a right tight beautiful spin and lost 5,000 feet. Now, this particular manager was a pipe smoker, and when we got back on the ground he couldn’t even get the darn thing in his mouth he was shaking so hard.”

After Brown’s passenger got his mouth and his pipe connected, Cessna engineers took a hard look at the newly modified 337 wing. They found that the new production process being used to get a sharper edge on the wing’s leading edge—the rollers would bend the aluminum tighter mid-bend—left a small ridge in the aluminum. While virtually unnoticeable on the ground, in the air the kink induced stalls well above the design airspeed under certain conditions, causing the aircraft to depart from controlled flight. The production process was modified and Brown was vindicated.

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