Mooney Reset: Cutting Build Costs

Legacy models are hobbled by high build-hour requirements. Investments at Kerrville aim to cut production time by as much as half.

Even if the likes of a Cirrus or Lancair hadn’t come along, builders of metal airplanes like the Mooney M20 series were headed for a box. As volume diminished, the airplanes remained as complex as ever to build, with thousands of hand operations and individual parts. Economy of scale had evaporated.

Now, with an infusion of Chinese capital, Mooney’s Kerrville, Texas, factory is confronting this challenge the only way it can, with a fundamental rethink of the production process and carefully focused injection of investment in digital and automated manufacturing, essentially mirroring what Lycoming has done to remain competitive. We covered this in detail in the February 2015 issue of Aviation Consumer.

Yet Mooney’s circumstance isn’t parallel to Lycoming’s because even as it struggles to retool its legacy products, it will soon introduce clean-sheet airplanes—the M10 series—specifically designed to be fast and efficient to build. We were told on a recent visit to Kerrville that the new airplanes are likely to be built partially or entirely in the Texas plant, with an eventual assembly operation in China.

Revitalizing the M20

The sidebar summarizes Mooney’s two new M20-based derivatives, the M20V Acclaim Ultra and the M20U Ovation Ultra. While neither of these could be considered true clean-sheet designs, they do represent substantial improvements on the previous M20 models. But the real story is how Mooney hopes to make massive efficiency gains in the way the airplanes are built. As these airplanes near the $800,000 mark, Mooney clearly doesn’t have much more headroom to raise prices, so sustainable profits will likely accrue from reducing both the time and cost of building them.

We toured the plant with Rob Dutton, who’s Mooney’s recently hired chief manufacturing officer. He comes to the job from a long career in aerospace, mostly on the commercial and transport side. We first visited the Kerrville plant 20 years—and two owners—ago and the changes have been dramatic. The assembly line has been drastically shortened with fewer stations and, as has every other company in aerospace, Mooney has embraced the lean, kanban-style of manufacturing that stresses low inventories and data tracking of everything from small fasteners to the man hours required to build major structures like wings and fuselages.

Physically, the place is still recognizable, but barely. The cavernous assembly hangars, once dark caves, are now brightly lit with modern LED lighting, fresh wiring and paint. During our visit over two days, the ancient back shops were still a work in progress, with old office modules being ripped out in favor of modern replacements.

Production equipment remains a mix of the old and new, but what new stuff we did see improves both productivity and quality to the extent that Mooney is also doing what Lycoming is doing: bringing many jobs they used to outsource back in-house. The company is also using its production capacity to build parts and structures for other aerospace companies, something it has done before.

Selective Composite

Mooneys have always had bits of plastic for fairings and interiors, but the new M20U/V aircraft will have a major composite component in a new cabin shell with composite doors. Dutton says this does two things: It makes for better-fitting, quieter doors and shaves assembly time. Mooney had originally planned to outsource the doors, but when an analysis showed they could be built in-house for a quarter of the price, the doors came back in. The shell itself is made by a vendor for now, but it might be manufactured in the Mooney shops, too, especially once the M10 production gets started.

“The new composite shell takes the place of a lot of sheet metal parts and also the fasteners that put those sheet metal parts together,” Dutton says. “And you have to remember when you’re hand-building an airplane like this, you have to do a little bit of trimming, a little bit of adjustment to make them fit. The composite shell will bring a static size and shape and won’t need any adjustment. We can just put the shell over the roll cage, make it fit and fair, and tie it down,” he adds.

Before that happens, assemblers will have much better access to the fuselage frame to fit wiring, plumbing and control circuitry. As for the roll cage, the individual 4130 steel tubes are now CNC cut and welded in a jig that assures consistent shape and dimension. That tube cutting is done by a vendor, but that too may eventually come back into the factory.

As for the shell, it’s a major reducer of build hours. “It’s a big savings in labor, both in assembly and piece parts. When you rivet, you need two people and we’ve eliminated some of that. And you don’t have to buy that shell until later down the assembly line and you don’t have to install it until later,” Dutton says. That means avionics and systems can be installed, literally, before the roof goes on.

Does this mean aircraft builds are approaching automotive quality and repetitive accuracy? “I wouldn’t say it’s approaching automotive quality, but it’s pretty good for aerospace manufacturing,” Dutton explains.

Moving Forward

Dutton says the wider use of CNC equipment will inevitably produce a more accurate airframe, better fits and higher quality, but there are limits to that when building an old-school airframe like the M20. “Moving forward on a new airplane like the M10, the design of the parts is all being done in a CAD system, so the tolerances on that airplane will be a lot tighter,” Dutton says. “That airplane will go together a lot more toward the automotive model,” he adds.

Interestingly, as the new CAD-CAM technology integrates with the existing factory in Kerrville, there may be further efficiency and quality gains for the M20. “If we have to do any redesign or improvements on the M20, I’m sure we’ll use that same technology. We have used some CAD on the M20, but a lot of it is still on old two-dimensional drawings,” says Dutton.

Because it has so many discrete parts—many of them cut and shaped aluminum—a large number of hours are devoted to simply handling the parts necessary to build larger aluminum structures. And that aluminum has to be heat treated before and after the various shaping operations. “Our core capability here is sheet metal fabrication and forming; brake forming, hydroforming, roll forming. We would not be able to do that as efficiently as we do today without a heat-treat process,” Dutton says. At one time, Mooney had a salt-bath heat-treat system, but that was removed when the company went into hibernation in 2009. When the company returned to production, parts had to be sent out for heat treating. That required shipping parts back packed in dry ice to retain the treatment. If it sounds inefficient, it was. “It was a logistical nightmare and an extreme expense,” Dutton says. Now, with a nearly million-dollar investment, the company has its own heat-treat facility and can take in work from other companies while also smoothing the production process. Further, with the new heat-treat process, the parts distort less, requiring less remedial work to obtain acceptable fits.

Half the Hours?

During our factory walkabout, we asked Dutton how many build hours he thought could be taken out of the typical M20 airframe. This remains an unknown, but reducing the hours by half seems possible.

“I’m sure the composite shell and the doors are just one thing that’s going on now. But take the wire harness. You’d think a wire harness is a wire harness, but if you remove wires and a dozen connectors, the part is easer to build and takes less time to install,” Dutton says.

Although the investment in both the Kerrville shops and the company’s Chino, California, facility has been considerable, there’s room to make more. But it will require sales volume to justify it. “We have a list of investments we want to make. One of the next we plan to make is a new CNC machine for the machine shop. That will really increase our output capability in the machine shop,” Dutton explains. As far as further automation, we asked if a factory like Mooney’s would ever see the kind of robotics found in the typical automotive plant. “I can’t see that happening in this facility. I don’t see that kind of investment giving a payback in any kind of short term,” Dutton says.

Volume-wise, the factory is capable of about two aircraft per month, but with little addition to overhead other than some additional labor, it could expand that considerably, something it will need to do to get back to break even. What remains to be seen is if Mooney will find sales to justify such expansion. When the M10 is integrated into Kerrville, the venerable factory will become sui generis for GA manufacturing.

Paul Bertorelli is Aviation Consumer’s Editor at Large. In addition to his valued contributions to Aviation Consumer, his in-depth video productions on sister publication AVweb cover a wide variety of topics that greatly contribute to safety, operation and aircraft ownership. When Paul isn’t writing or filming, he’s out flying his J3 Cub.