Sweeping changes at Teledyne Continental
Floridian Tim Maynard painted what he thought was a light coat of sealant on the case flanges of a Teledyne Continental six-cylinder engine. If it's applied correctly, this sticky goo becomes tacky in 15 to 20 minutes. Our class was preparing to practice applying a length of silk thread along the flanges. When the case halves are bolted together, the silk thread creates a dam that prevents oil from leaking out between the case halves. Maynard put on too much goo, so we waited — for three days. We never did get to apply the silk thread, but perhaps that's why we were attending the Teledyne Continental Motors (TCM) advanced technician training class.
"So far we've taught this class to about 500 mechanics," said TCM's Don Fitzgerald, the primary instructor during the weeklong class. "Our goal is to have four classes going at the same time."
Under Bryan Lewis, president since 1991, TCM has been working toward one goal — to become the preeminent aircraft piston engine manufacturing facility in the world. Instead of applying a few small band-aid fixes here and there, Lewis has implemented sweeping changes at the TCM factory in Mobile, Alabama. These changes range from a complete manufacturing facility upgrade to technician education to new powerplant control systems.
The more visible changes, such as the addition of new manufacturing equipment and installation of a computer system that tracks and controls operations on the manufacturing floor, are taking place right now. But changes have been in the works for a long time. TCM's comprehensive Top Care Program, outlined in 1997 TCM service information directive (SID) 97-2, was started as a research program in the early 1990s. This 28-page directive lists TCM's cylinder improvements and defines the company's philosophy governing cylinder care. Since 1997, TCM has further spread its service and maintenance information by refining older service data and issuing new comprehensive bulletins.
The company also has been doing a lot of testing. According to Fitzgerald, one series of tests measured engine power output after removing the compression rings from the pistons in an engine. Contrary to guidelines outlined in FAA advisory circular (AC) 43.13-1B, which say that cylinders should be removed if the total leakage is more than 25 percent, TCM's tests revealed that where the compressed gases leak out of the cylinders is much more important than the amount of leakage. This testing is the basis for Service Bulletin M84-15, which governs compression testing procedures for TCM cylinders. After I calibrated my compression gauge in accordance with this bulletin, cylinders with compression pressures as low as 50/80 were airworthy, as long as the compression leakage didn't occur past the valves.
Vice President of Manufacturing John C. Oakley and his team have been putting in long hours installing millions of dollars' worth of modern, computerized, numerically controlled (CNC) machine tools. They've also been busy creating step-by-step manufacturing procedures that are tracked and monitored by computers, and creating computer programs that allow TCM to keep a tight rein on each step of the production process.
Oakley throws around terms such as computer-aided processes (CAP), statistical process control (SPC), and coordinate measuring machines (CMM). In everyday language, TCM is modernizing its company. When the improvements are in place, TCM will be able to pull records on each part it produces — every task will be dimensionally tracked by sophisticated measuring equipment and that data will be fed into a computer that double-checks each step during manufacturing before the next step is implemented. The result will be identical parts — identical in size, weight, and processes, and built to very close tolerances.
One area that illustrates the capabilities of TCM's new equipment is the final cylinder-wall hone pattern. This very important finishing touch to the cylinder walls determines how well the rings break into the cylinder walls and has an effect on oil consumption. Today, the hone pattern on every cylinder is charted by electronic measuring equipment, and that data is electronically stored. Again, the result of TCM's investment is the ability to produce a cylinder that is built to tighter standards. If field experience and repair data from cylinders returned to the factory suggest a change to improve TCM's cylinders, that change will be made to the standard.
Fitzgerald, when he's not creating the technician classes, is the manager of TCM's Web site ( www.tcmlink.com). The expansion of TCM's information technology division — this division has grown to 20 employees — and the growth of its Web site are further evidence of TCM's willingness to use modern methods to achieve its goal. A few years ago, the TCM Web site was little more than an address. Today, it's a treasure-trove of information about TCM engines. Visitors can take a site tour and any owner of a TCM engine can enroll in the aviator services section of the Web site for free. In addition to the boxful of printed material they receive, class attendees are automatically enrolled in TCM's information services. This permits access to copies of instantly revised parts books, service information, and other data. As maintenance shops and personnel grow accustomed to using this service, TCM may decide to suspend the yearly paper revision service of its manuals.
But back to class. Nine of us gathered at the guard shack that first Monday and got our passes for the week. We were two A&P mechanics from Mission Aviation Fellowship — Floridian Tim Maynard and Steve Holz, who is MAF's director of training. Alaskan Tim Maynard (yes, we did have two Tim Maynards in the class) is an A&P and pilot who commutes from Anchorage, Alaska, to his job in Kenai, Alaska, in his U-3B, a military version of a Cessna 310. Easygoing, quick-to-smile John Randall of Pearl River, Louisiana, is retired from flying offshore helicopters and now claims to be "a consultant to several friends who have Continental engines." Two small maintenance shops were represented by Dave and Sandi Palacios of DP Air in Corona, California, and Tucker Brugh, a recent A&P school graduate from Cerritos, California, who sees his future devoted to rebuilding airplanes. Filling up the last two chairs were Tom Carr, Cessna technical expert from Cessna Pilots Association, and yours truly.
Every morning at 8 we hit it. Lunch was brought in and we ate well. It was just after lunch on Monday when Maynard laid on the sealant. It's possible that the overzealous goo job could be attributed to his third chocolate chip-macadamia nut cookie.
During the week, we toured the factory, attempted to set up the fuel pressures on one of TCM's continuous-flow fuel injection systems, were briefed on TCM's FADEC system, and were loaded down with a large boxful of TCM reference material and videos to take home (TCM will ship the materials home for you free of charge). We learned from our world-traveling mission mechanics that fundi is the Swahili word for expert in all things and that tukang means the same thing in Indonesian.
We listened as Fitzgerald went over the highlights of each system and followed along on the excellent exploded drawings in the workbook. Then we all gathered around to do hands-on training such as taking apart an engine-driven fuel pump or rewinding an impulse coupling spring.
Enrollment in the weeklong class costs $750. TCM has arranged an attractive rate for its students at a nearby hotel. A rental car was needed for the week because restaurants and motels are not close to the Mobile Downtown Airport, where the school is located.
After lunch on Thursday we were issued safety glasses, earplugs, and green plastic toe protectors. These toe protectors were strapped over our shoes, and we clopped along the concrete factory floors. We sounded like a retired posse riding into town. As we toured the plant, everyone we saw seemed genuinely proud of TCM and happy to be working there.
Oakley said the new CNC machines constantly monitor and adjust themselves to adhere to the design parameters and tolerances. These smart machines achieve much tighter manufacturing tolerances — as little as 125-millionths of an inch — than older equipment.
Oakley showed the class two machines set up for cylinder work. One installs both valve guides and the intake and exhaust valve seats, and screws the aluminum head down onto the coarsely threaded steel barrel. Next to the big room-size CNC machine was an old veteran craftsman doing the same job — he did it by waiting for a heated cylinder head to come down the conveyor belt from a 600-degree oven before he manually installed the valve guides and valve seats, and (using very thick gloves) screwed the head onto the threaded barrel. The CNC software and mounting hardware weren't quite ready for this type of head, so a few cylinders were still being done the old-fashioned way.
At this stage the barrels have a solid round mounting flange. After the head is properly screwed down onto the barrel, the next machine cuts the sides off the steel cylinder mounting flanges (so the cylinders can be mounted close together on the case halves), drills the flange mounting holes, and spotfaces a radius around each mounting hole so the cylinder hold-down nuts press against a flat surface. Oh, yeah, it also reams both valve guides.
While this sounds more like a series of mass metal removal tasks than close tolerance machining, the point is that these two machines do these tasks over and over without fail and while maintaining very tight tolerances.
To ensure that the CNC machines are accurate, TCM plans to install climate-control equipment in its manufacturing plant by this summer — more evidence that TCM has set lofty goals in upgrading and modernizing its manufacturing facility.
Back in class, Fitzgerald introduced our ignition systems instructor Tim Davis. In 1986 TCM bought Bendix Ignition Systems. Davis joined TCM a few months later. A natural teacher, Davis gathered up the class and led us through the thicket of lines of magnetic flux and electromagnetic induction, then broke down the differences between riveted and snap-ring impulse couplings until we finally arrived at magnetoville. Davis, who has a bright, low-key style, kept the subject alive with pronouncements such as, "Magnetism is one of the great mysteries of science — it's right up there with gravity." You couldn't help but learn.
Davis concluded by asking if anyone had a copy of Bendix Scintilla Bulletin 1A, issued in July 1930. (If you do, please contact him since he would like a copy to complete the company archives.)
Although there wasn't time to get a ride in a FADEC-equipped airplane — TCM has installed FADEC systems on certified aircraft engines such as the IO-240 engine on a Diamond Katana, the IO-550 engine on a Cessna 210, and the IO-520 engine on a Beechcraft Baron — the class was prepped on the benefits of the system.
FADEC means full authority digital engine control, and this system should be good news for pilots who can't seem to get good life out of their engines. The reason is that the TCM FADEC system automatically controls the two variables — ignition timing and fuel mixture — that most affect engine operation.
TCM's continuous-flow fuel injection system has proven to be a simple, dependable system for more than 40 years. But it's getting pretty long in the tooth. The FADEC system is much more sophisticated and, like TCM's new CNC manufacturing machines, constantly monitors and adjusts both the ignition timing (depending on the power setting) and the fuel-air mixture (to keep CHTs below 380 degrees) delivered to each cylinder.
The result is easier starting, more power delivered during takeoff and climb, and better fuel economy. The differences between a FADEC-equipped engine and an engine without FADEC can be likened to the differences between a Model T Ford and a modern automobile. No more hard starting, no more tweaking the mixture — just push the lever and your silent copilot, Fred FADEC, will figure the rest out for you.
In addition to improved engine operation from start to shutdown, FADEC-equipped engines are easier to maintain. Should an engine problem occur, technicians can download engine operation numbers from the FADEC system and send the information directly to the TCM Web site so that factory technicians can provide troubleshooting advice. Plug-in troubleshooting and engine data tracking are available for today's outboard boat engines, and it's good news that FADEC will soon be available for general aviation aircraft. Lewis projects that a FADEC-equipped IO-550 engine will be certified later this year.
I left Mobile and the TCM maintenance school excited about the future of TCM and its engines. The company is modernizing its facility and that's good news for GA. After a week at TCM's comprehensive school, nine TCM engine fundis went out into the world. A schedule of technician training classes for 2002 can be obtained online ( www.tcmlink.com/aviationtraining/).
E-mail the author at [email protected].
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