This technical information has been contributed by
Sonic Aerospace, Inc.

Precision Machining Company Takes on Challenging Aerospace and Aviation Projects

Laser Processing

Custom-machined satellite, rocket, and jet engine parts are specialties of a company known for its FAA repair work and tool and gage production

David Gaines
Design-2-Part Magazine

Custom-machined satellite, rocket, and jet engine parts are specialties of a company known for its FAA repair work and tool and gage production.

Sonic Aerospace, Inc., located in Chandler, Arizona near Phoenix, has carved out some very specific niches in the aerospace and aviation industries with its precision, high-end machining and assembly capabilities. The company is a certified FAA Repair Station and also handles a variety of custom machining projects. Through its Sonic Tool and Gage sister company, the company also engineers and manufactures tooling and gages for the aerospace and oil and gas industries. In addition to these three niches, Sonic Aerospace also provides turning, milling, and grinding for the electronics, defense, semiconductor, and medical industries.

"We specialize in the repair and overhaul of gas turbine engines and secondary power source components, specifically, gearboxes, oil/fuel pumps and inlet housings," the company states on its website. "Sonic Aerospace also has the ability to supply engineering support to our customers. Sonic's aerospace repair facility serves the aerospace gas turbine industry and the industrial turbine industry by manufacturing and restoring turbine engine components for original equipment manufacturers, aircraft operators, and maintenance providers. We hold FAA Repair Station status, complemented by a complete in-house Repair Development Engineering staff repairing APU, flight engine, and aero-derivative parts."

Besides the repair and overhaul of aerospace and aviation parts and components, Sonic Aerospace machines a variety of high-tech, precision custom parts that have critical end uses. "We make satellite parts, rocket parts, jet engine parts, and APU parts (auxiliary power units) that are in the tail of a plane," said Mark Willmering, president and owner of Sonic Aerospace and Sonic Tool and Gage, in an interview. "We also make aluminum housings and fuel controls. We machine castings and machine hog outs and forgings. We make valve bodies, hydraulic engine pumps, spools and sleeves, engine gear boxes, and we make custom gages and fixtures and tooling. We're very unique in the three areas that we work in—custom work, repair work, and tooling and gages."

Most of the measurement gages that the company designs and builds are for the oil and gas and aerospace industries. Their primary function is to measure a groove in a part. The tolerance of the diameter is +/- 0.001-inch on a 0.068-inch gage point depth. The gages use a 50 millionths indicator to measure that dimension. "On a gage like that, when you're measuring +/- 0.001-inch tolerance of a diameter, the gage has to be basically 10 to 1," Willmering said. "That gage has to repeat within a tenth all day long. The indicator that's involved with this measurement is a 50 millionths indicator to display the readings."

The oil and gas industry basically uses the gages to monitor the electronics in a drilling pipe. The drilling pipes have a gold plated wire that runs through the pipe vertically and horizontally to provide information during drilling. All of the information, including temperatures, comes up through that pipe.

"They can get the temperature of the drill bit, as well as the pipe, and they can find the drill bit's location," said Willmering. "They can get that information from any well, anywhere in the world by transmissions over the internet. Our gage checks the diameter and the angle of the groove in the pipe. The electronics go inside of the groove, so if the groove isn't the right size, the electronics will pop out. That's why the precision on the groove has to be so precise. And the pipes are very expensive; you're looking at probably $10,000 per pipe. So this is very specialized measuring equipment."

Company Involved in Aerospace and Aviation Industries for Many Years

Sonic Aerospace ( and Sonic Tool and Gage were originally another company that had been started by Mark Willmering's father with a specialty in aerospace and aviation parts and components. "My background has always been in manufacturing," says Willmering. "A family business was started back in St. Louis, where we made the landing gear for the F-4 phantom jet for McDonell Douglas. We had a 300-man shop that my father owned. We had union problems, so we sold that business and moved out to Arizona. Basically, I got involved in the family business in Arizona, and I've been doing aerospace manufacturing ever since."

Mark Willmering started Sonic Aerospace and Sonic Tool and Gage in 2005 in Chandler, Arizona. In addition to operating an FAA Repair Station, the company manufactures new, custom parts for the aerospace and aviation industries. It also designs and builds its own tooling and gages. "We make a lot of rocket parts and engine parts," says Willmering. "We make custom tooling and gages for specific issues, and we design and engineer them to customer specs. We make new parts for Honeywell, so we thought if we can make them, we can repair them. This was the whole idea for the FAA Repair Station."

As an FAA repair station, Sonic Aerospace repairs and overhauls aerospace and aviation components. Most of the company's repair and overhaul work consists of utilizing a certified DER (designated engineering representative) to monitor the work. It gives the company authorization to repair high-tech aerospace and aviation parts. "We make a spool and sleeve for one repair job," states Willmering. "We match-set grind it to very close tolerances—50 millionths—and make a new spool for the sleeve. We have a repair process, so we can repair that spool and sleeve so the customer doesn't have to make a new one. And we can repair it for about half the price."

FAA Repair Station Saves Costs

According to Willmering, the company's FAA Repair Station saves OEMs a great deal of money because buying new parts can be avoided. "This is the main servo valve for the hydraulic systems on a helicopter," he says. "We make other aviation parts where we make sleeves and bushings, or we take a complex housing and take the bearings out and repair them. A lot of times, these actuator housings have a bore that's worn out, or a spring or plunger in there that gets worn out. So instead of having to buy a new part, we can sleeve it. We go in with a stainless steel sleeve, sleeve it, and then grind it and bring it back to size. This repair is probably one-third of the cost of having to buy a new one, so it saves the customer a lot of money."

All of Sonic Aerospace's and Sonic Tool and Gage's machining work is high-precision, complex, custom work with very close tolerances, often within thousands, ten thousands, and millionths. Sonic's assembly work is also demanding, often requiring the company to turn out complete subassemblies or complete products. Willmering says one of the keys to the company's success is the precision, high-quality CNC machining equipment that they enlist for this work.

"Being able to cut all types of materials is important," he says. "These machines cost more than most CNC machines, but they're capable of producing very precision results. We get better finishes with them, and better dimensions and better accuracy. We have to have this high-end equipment for the type of work that we're doing. You have to have Korean or Japanese types of machines that are very precision and high-tech. These are the best manufacturers of this type of equipment."

The company's president says that you need a machine that's very rigid and strong to cut the aerospace types of materials. "One exotic metal, MAR-M-247®, is very expensive," he continues. "It's made out of 66% nickel and 10% tungsten-carbide. This material can go up to 2,000 degrees. It can be used for the hot section of a jet engine—the backside that goes up to extremely high temperatures. There are lots of German and Swiss machines out there, and they are also very good. The Chinese and Taiwanese machines aren't as good as the other ones I mentioned. They can do aluminum because it's very soft."

Engineering Design Services Include R&D, Complete Design

Not only is the company's engineering department specialized in this type of complex, critical work, but the department is also able to offer complete design services, from the initial idea to final design. "We offer design services for different parts and for our custom gages," says Willmering. "We use our CADKEY program for the gage design, and handle it from start to finish. We have design engineers that can handle complete designs, and we also design our own tooling.

"We have a lot of diverse capabilities for design and manufacturing," he continues. "And, our work is very complex. We're not making simple stuff here; it's all very high-tech and high-precision work. We also use all different types of materials, like aluminum, Inconel®, Hastelloy®, and Haynes® 188. We can handle all of the exotic metals. A lot of people don't want to touch them because they're too hard to work with. The reason we can do them is because we have very skilled machinists that have been in the industry for 20 or more years."

Sonic's engineering department designs and develops work instructions for the aerospace and aviation parts before they go out onto the shop floor. They design the parts in CAD programs with solid modeling, and program the CNC machines with CAM programs. The company's engineers still have to do mathematical equations and tolerancing, and they also make shop travelers, which are the work instructions. The travelers have all of the different work steps and a sketch, so that machine operators can run the parts on the shop floor. "They use Mastercam and GibbsCAM to make the G codes that tell the CNC machines which tool to pull up," Willmering explains. "They load it into the machine with a little flash disk. The machine operator then looks at the tool list and loads the tools into the machine in the right order. Then you run the part. We have machines that can hold up to 100 tools, and we make some parts that take 98 tools to machine."

ERP Software Helps Streamline Plant Operations

Willmering was asked how Sonic maintains efficiency, high quality, and cost effectiveness in a field as complex and demanding as this one. "We use JobBOSS for our ERP (enterprise resource planning) software," he replied. "We can do quoting, shop travelers, estimating, purchase orders, financial statements, scheduling, and outside purchase orders. When we do a traveler for the shop floor with work instructions, if it has to go for an outside process, like painting, we can take the information that the engineering department has and create a purchase order right from that. When the employees on the shop floor use a traveler, they're all bar coded so they can be scanned in and out of the job."

With the information scanned in, JobBOSS is then able to provide real-time job costing from machine time, allowing engineers and managers to see exactly how long parts take to process. These data allow the company to track machine time for analysis and capacity planning. "We can see how much open time we have on machines for scheduling," says Willmering. "So we know if jobs are running over or less, and it can recalculate all the other parts downstream. We can also do 'what-if' scenarios—'If this one finishes, can we do this other one?' And we can do finite and infinite scheduling, so it allows us to schedule two different ways. It's very sophisticated and it's all SQL-based."

A fair amount of documentation, validation, and quality control has to occur for production of these complex, critical parts and components. Sonic Aerospace and Sonic Tool and Gage are AS9100 registered for aerospace projects and ISO 9001 registered for all other work, and they are also ITAR registered for aerospace and defense projects. "All of our paperwork and inspection reports are set up for ISO and AS standards," says Willmering. "This gives us the quality control standards we need. With these systems and procedures in place, it allows us to follow quality control. So we have a quality control procedures manual and have all of that documented on our system. We also use SPC data for documentation and validation, which comes from the ERP program."

One way the machining company handles quality assurance inspections is with Nikon CMM Manager—software that inspects the parts and assemblies very precisely. The program allows inspectors to import a CAD solid model into the coordinate measuring machine (CMM), a large piece of equipment with a probe on it to measure specific dimensions.

"We can inspect any dimension on the part by importing the design model from our engineering department," says Willmering. "The quality department will then inspect what we make based on the solid model. We do a lot of work for NASA. They don't really give you blueprints now; they're trying to go paperless, so they give us a solid model. We have to manufacture the parts exactly to their model. We can use the CMM software by moving the probe around manually or we can automate it by building a program with the model and then let it go on its own. It really saves us a lot of time and makes for more repeatable quality checking."

Sonic Aerospace provides many secondary power source components, specifically, gearboxes, oil and fuel pumps, and inlet housings. Many of these parts are eventually installed on jet engines or auxiliary power units (APUs) and could be used for helicopters or fixed wing airplanes. The APU runs the plane when it's on the ground, and if the plane ever loses power in the air, it automatically starts and gives power to the plane. "We make different parts for the APU, which has to start every time, no matter what," Willmering says. "They test and engineer them so that they are 100 percent reliable."

Another challenging component that the company manufactures is a wing shaft for a Bell helicopter. As the helicopter is flying through the air, if there is turbulence, the blades will bounce around. The part goes into the assembly that dampens the blades to keep them from bouncing. "This is a very critical part too," says Willmering. "In fact, every part that we manufacture has a critical use."

Since there is a need in aerospace and aviation circles for machined prototypes, Sonic Aerospace provides them for their OEM customers. "We work a lot with an OEM's engineers to do R&D work for prototypes," he says. "We do a lot of concurrent engineering to give a client our expertise on how to manufacture a product cheaper, better, and stronger."

Concurrent engineering is used to develop a new part by simultaneously designing, engineering, and performing R&D on it. "After a lot of these aerospace parts go into production, you can't change them," Willmering maintains. "For example, on the R&D side, they have to try different things to get the combustors working for air flow and fuel efficiency. So there's no perfect science on how to fine tune these jet engines. They also have to deal with pollution controls and vibration. So they have to make different parts to see how it affects how the engine runs to get the most power and fuel efficiency. So concurrent engineering is when they're trying different things on the R&D side to see what really works. But when the parts go into production, they don't change them. So there is a lot of work upfront on the R&D side. Our engineers work very closely with their engineers. Engineering is a very big part of our business."

Company Handles Hydrogen Fuel Cell Regulators and Components

Sonic Aerospace is also prominent in hydrogen fuel valve manufacturing for the automotive industry. On one project, the company engineered research and development components with an automotive customer and brought the products through the development phase into production. "Our expertise comes from very precision, complex valve bodies and regulators," says Willmering. "We made hydrogen fuel cell regulators that go into the fuel tanks of Prius fuel cell cars. Those regulators were all hogged out of solid pieces of stainless steel."

The hydrogen fuel cell project was for the Japanese automaker, Toyota. "We machined the regulator for the company and then they installed all of the other parts," Willmering said. "The whole assembly goes into the gas tank. They had three of these tanks in the Prius car. One regulator would go in each fuel tank that they manufactured. This work was for an R&D group in the United States; Toyota paid them to develop it and then make it. They were a great customer."


Inconel® is a registered trademark of Special Metals Corporation.

MAR-M-247® is a registered trademark of Martin Marietta

Haynes 188® is a registered trademark of Haynes International Inc.

Hastelloy® is a registered trademark of Haynes International, Inc.

Heli-Coil® is a trademark of The Heli-Coil Coil Company.

This technical information has been contributed by
Sonic Aerospace, Inc.

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