Waggism, playful lightheartedness, is the last thing one would expect to see at a facility dedicated to the deadly serious business of building FAA-certificated aircraft. But then I met Sally, her name printed on an aluminum placard in red Sharpie on the wide end of a fixture used to build tail booms at Enstrom Helicopter in Menominee, Michigan.
Curious, I asked Dan Nelson about it. Was this the work of some unknown wag, an aeronautical version of Kilroy was Here?. Taking a moment, he carefully put down his Cleco pliers and explained that Sally was the name of the piston-powered helicopter just conceived at the factory. “We started naming them some months ago,” said Dan, a sheet metal master who introduces newcomers to the craft and mentors their mastery of it.
“There was a picture on Facebook of a fleet of our helicopters on the ramp for delivery, and someone said we should start naming them.” The piston-powered F-28F and 280FX get girl names, and boy names identify the turbine-powered 480B. “It’s just for fun,” he said with the unapologetic tone of a father talking about his children.
Perhaps naming these gestational helicopters isn’t so waggish. Expectant parents often name the nugget of their baby to give it an identity, to make it more than a bump, to connect on a more intimate, personal level. The only real difference is that the helicopter’s names stay in the womb. Like all parents, the customers who take the newborn Enstrom home have the naming rights.
The riveted monocoque is just one appendage connected to the welded steel-tube pylon that is the Enstrom’s thorax. Working in robust rotating fixtures that look like complex gyms—yellow for pistons an green for turbines—it takes Enstrom’s state-certified welders about three weeks to weld a pylon, said Dennis Martin, Enstrom’s director of sales and marketing.
The welders work with pre-notched tubing, he explained, and the three weeks includes their final fitting, sand blasting, multiple inspections, and a light skim coat of primer that makes imperfections stand out. “We like steel because it’s easier to inspect and repair,” said Martin. “But the main reason is that steel will absorb a great deal of energy.
“If you look at the S-N Curve [a plot of the magnitude of an alternating stress versus the number of cycles to failure for a given material], once it fails, steel continues to absorb energy, which means it is not transferred to the occupants. It doesn’t have a sharp drop off; once aluminum or composites fail, it’s done—it doesn’t absorb any more energy,” said Martin.
Just around the corner, in the composite shop, Tom Retlick is laying up the some seats that combine different layers of foam and glass that work in concert to provide lightweight rigidity, comfort, and a degree of energy absorption. Just celebrating 23 years at Enstrom, he’s surrounded by his work, artistry embodied by the split molds for each model’s cabin and attendant fairings.
The heart of Enstrom’s birthplace is the climate-controlled cube that is the quality department. “It’s such a crazy juxtaposition,” said Roger Hardy after setting a raw casting of the idler pulley for the piston power train in the Conner CNC measuring machine. Just outside those doors there are artisans bucking rivets, welding steel, and laying up and cooking composites “all under one roof with CNC measuring and milling machines.”
“It takes some time to program the machine” to measure dozens of specific points on a part, said Hardy, who starts the effort with the part’s drawing. “But it goes to the exact same point on every part with a consistency that gives a true measure of each part.” He’ll see this part again, after it takes its turn in a CNC mill to become a finished idler pulley.
After making sure my curiosity had satisfied its current queries, he thanked me, and returned to work, as had all of the artisans I’d talked to this day. Each of them was knowledgeable and friendly, and prompted by my questions, they eagerly shared their knowledge in terms neither patronizing nor overtly technical. As a group, their personality was one of proud parenthood. — Scott Spangler, Editor
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