Hartzell Engine Technologies - No Mistaking the Quality

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July 2015

From alternators to turbochargers, Hartzell Engine Technologies is committed to producing an array of accessories and components that provide Cessna owners with better performance, reliability and value.

You might say that Montgomery, Ala.-based Hartzell Engine Technologies (HET) suffers from a bit of an identity crisis.
Today Hartzell Engine Technologies manufacturers many of the accessories and components found under your aircraft’s cowling, but you likely think they’re made by someone else.
This can be confusing for you—and downright frustrating for the folks at HET.
Here’s the deal. Hartzell Engine Technologies, along with its sister company, Hartzell Propeller, are owned by Tailwind Technologies, Inc. And while the two companies are related, they operate autonomously.
The Hartzell brand is well recognized in General Aviation, and with the addition of HET the brand is rapidly growing beyond propellers. To help put an end to any remaining confusion, we need to start at the beginning.

How HET was formed
HET was formed back in 2010 when Tailwind Technologies purchased product lines from Kelly Aerospace Energy Systems. These product lines included turbocharger systems (originally Garrett and Rajay), alternators and starters (originally Prestolite, Aero Electric and Electrosystems), cabin heating systems (Janitrol Aero) and fuel pumps (Kelly Aero).
“The point of confusion within much of the industry is that since Kelly Aerospace continues in operation, it seems many people still think these are Kelly products,” explained Mike Disbrow, President, Hartzell Engine Technologies.
“We’ve operated separately and
independently from Kelly in noncompeting products since HET acquired the lines. Yes, these products were once produced by Kelly, but that’s where the connection ends.”

Five core areas, and growing
Disbrow said that the product improvements they’ve already completed are part of HET’s overall strategy to concentrate its efforts on being the best solution in five core product areas: alternators, cabin heaters, fuel pumps, starters and turbochargers.
He also explained that HET’s current products give the company a depth of offerings—not only for certificated general and business aviation piston and turbine aircraft, but also the experimental/kit aircraft, military helicopters and unmanned aerial vehicle segments.
While the current product spread is impressive, Disbrow said the company is always looking for opportunities to expand. “We’re committed to General Aviation by growing our market share through a combination of ongoing improvements and additions to our current products, and the strategic entry into new areas through acquisition,” Disbrow explained.
“For example, we bought the Lamar Technologies starter line in 2012, the Skytronics/Jasco alternator line in 2013, and last year [we] added Plane-Power alternators.
“The addition of Plane-Power products not only complements our family of alternators, but it also gives us immediate access into new markets,” Disbrow continued. “In particular, Plane-Power has several STC’d generator-to-alternator conversion kits that will open opportunities for us to serve new customers.”
Disbrow stressed that the purchase
of Plane-Power in no way includes any Sky-Tec starter products.

Getting better all the time
While Disbrow described a variety of recent improvements to many of the company’s products, these in particular may be of interest to Cessna Flyer readers.
HET’s ASG series alternators which are OEM on Cessnas contain rotors that are now 100 percent resistance bonded to improve durability. Both the rotors and stators are 100 percent electrically tested to ensure product performance and reduce out-of-box failures.
HET’s fuel pumps that are OEM on Lycoming engines for Cessnas now feature improved performance though tighter manufacturing tolerances. In particular, the fuel pump used on Cessna 206 aircraft has been improved to resolve a rough idle issue.
The Janitrol heaters used in many twin Cessnas have been improved by replacing the stainless steel combustion tube with Inconel®—the same material used in making turbine engine blades. These improved units, called the I-Series, eliminate the recurring inspection AD on affected heaters. (For more information on I-Series technology and Inconel alloys, see “Cabin Combustion Heaters: Maintenance and Troubleshooting” by Tim Gauntt in the November 2014 issue of Cessna Flyer. —Ed.)
HET’s turbochargers used on both Lycoming and Continental engines have been improved through the implementation of higher-precision machining and measuring equipment, as well as the addition of a high-speed balancing operation on all new and rebuilt assemblies.
HET also offers high performance replacement products for many Cessnas. These products include E-Drive and X-Drive lightweight starters for Lycoming engines (the E-Drive features a self-resetting torque limiter that is warrantied to provide kickback protection); Plane-Power generator-to-alternator conversion kits for many early Cessnas; and Plane-Power lightweight alternator replacements for older Ford-equipped Cessnas.

A $3 million commitment
Hartzell Engine Technologies recently put the finishing touches on a total modernization of its machining operations. The multifaceted project, valued at over $3 million, included replacing nearly all of HET’s legacy equipment with new computer numeric control (CNC) machining centers and automated coordinate-measuring machine (CMM) inspection equipment.
“Everything in here is light-years ahead of the equipment we replaced in terms of capability, precision and quality,” Disbrow explained. “This would be on par with what’s on the floor at any high-end machining operation and it puts us up with the leaders in aviation manufacturing.
“Not bad for a small company,”
he added.

Must-have automation equipment
While Disbrow and his production team are proud of every new piece of equipment in the facility, two machines in particular were at the top of their “must-have” list.
The first is the Mazak Horizontal Center Nexus 4000-II with the Palletech system. It’s used for the precision machining of Hartzell’s alternator housings and will soon be used for finishing operations on various turbine housings.
“It’s amazing to watch this machine in action. Its automation alone saves our technicians many steps compared to the old machining process,” Machine Shop Operations Director Brandon Stewart said. “Once the operator loads the Palletech ‘tombstones’ into the machine, it will operate unattended and produce very high quality machined products at a more efficient rate.
“Another cool feature is it can automatically machine multiple tombstones containing various part numbers in succession,” he added. “All the operator has to do is load the correct casting and the machine’s programming does the rest.”

Quality control and multiple inspections
While the components created with the Mazak and other new machines on the shop’s floor are incredibly precise, Vice President of Operations Rose Foster reports that every part that is produced in-house or received from an outside vendor receives an extensive quality control (QC) inspection before it finds its way into production stock.
Parts are inspected at controlled frequencies when entering the building and then again at each step throughout the product cycle. Every inspection is done using the highest quality technology available.
“Our new first-line QC inspection tools are two Brown & Sharpe Global Advantage CMMs,” Foster explained. “These inspection units are so precise that their probes can detect down to five microns of deviation. In addition, the air bearing CMMs [we have] are so sensitive that we have housed them in their own environmentally-controlled room.
“We have also equipped each CMM with Orion statistical process control (SPC) workstation software. This software places the emphasis on continuous improvement and is an efficient and effective way to bring SPC to the shop floor.”

Optimizing production in work cells
HET installed five new Mazak CNC machining centers and five new Hexagon/Brown & Sharpe CMMs in addition to other new production and inspection equipment required to upgrade each work cell. To optimize production and quality, HET has organized each machine into self-sufficient production cells. Each one produces its own specific family of parts.
“In addition to the machining centers, the cells have all the inspection and secondary equipment necessary to complete their parts within that cell,” Foster said. “This minimized queues and speeds the flow of materials throughout the production operation.
“Hartzell customers expect the highest quality and machines like these demonstrate just how committed we are to delivering on those expectations,” she added.

Making the switch without
affecting production
Disbrow said that along with the significant financial investment, the shop upgrade took a lot of planning and coordination so as not to interfere with HET’s production schedule.
“These are very sophisticated machines, and they required a fair amount of fixture design and programming to be able to produce and inspect these precision parts,” Disbrow explained.
“We actually had the equipment initially installed at Hartzell Propeller’s ‘skunk works’ hangar where their manufacturing services group set the machines up to run our parts, as well as train our machinists on their proper operation.
“Once each machine was dialed in to making our components, the old equipment was cleared out in Montgomery and the new unit installed,” Disbrow said. “There was very little production downtime.”

The goal: to lead in every category
“People who have seen all this new machinery often ask why we would make such a large investment in equipment and training while the General Aviation sector is down,” Disbrow said.
“To us it makes perfect business sense. Our goal is to manufacture products that lead every category we are in—both from a performance and a value perspective.
“The only way to do that is to produce the best products we can from the beginning of the process. And to do that we need the best machines in our shop.”
From upgrading the performance and quality of its core products to investing millions in a state-of-the-art manufacturing facility, Hartzell Engine Technologies is doing what it takes to deliver on its promises.

Dale Smith has been an aviation journalist for 30 years. When he’s not writing aviation articles, Smith does commission aircraft illustrations specializing in seaplanes and flying boats. Smith has been a licensed pilot since 1974 and has flown 35 different types of General Aviation, business and World War II vintage
aircraft. Send questions or comments to

Hartzell Engine Technologies