Recip Technology: Did I Hear a Radial?

That expertise and customer care attitude is valued by Covington. It has very low turnover and its story is very similar to Rust’s Flying Service up in Anchorage. Some mechanics really like to work on radial engines. Blaine Abbott says, “We have a great in-house training program. Usually a mechanic will start out in teardown and work through our OJT program. We encourage our mechanics to get their A&P or repairman certificates. We have mechanics trained and developed with the skills and confidence to go out in the field and work at the customer’s location.”

Overhaul customers

They explained that in the past 40 years the customer base has flipped because most of the light freight haulers are gone. Now about 80 percent of their customers are in the agribusiness flying AgCats, Weatherly, Air Tractors, and Thrushes. Another 15 percent are in the air taxi business and the rest are hobby customers. They generally fly Beavers, Otters, Harvards, SNJs, Stearmans, BT 13s, and AT6s.

Seeman says, “Our radial overhaul business is still pretty good. Covington is now a global company and has a worldwide customer base. About 40 percent of the business is export. We estimate that about 8,000 to 10,000 R-985s and R-1340s are still operating. These engines can generally operate between 1,200-1,600 hours of time between overhaul (TBO). Radials come in for overhaul because of high oil consumption, propeller strikes, Airworthiness Directive 68-09-01 compliance, or they have timed out.” The AD must be accomplished at 1,200 or 1,600 hours depending on propeller installation. To accomplish this, the engine must be disassembled to the point it is more economical to overhaul than to just comply with AD 68-09-01.

Tools, fixtures, and parts

I asked about the production side of the overhaul process, especially about their tools and fixtures and parts inventory. Seeman says that they are “currently overhauling around 180 R-985s and R-1340s a year. If we have the parts on hand we can overhaul a radial in about 30 days.”

Abbott says that “a huge number of radials were produced during the war years. About 39,000 R-985 Wasp Juniors were produced between 1929 and 1953, and 35,000 R-1340 Wasps were produced between 1925 and 1960. Many of these engines and parts were offered on lend lease agreements to other countries. Also, a lot of surplus left the United States and went to third-world countries. Parts suppliers have been buying up that surplus from those countries and putting the inventory back on the U.S. market.

“There are parts manufacturing approval (PMA) businesses that are manufacturing radial engine parts and accessories. Covington is a (PMA) holder and manufactures gaskets and seals for the Wasps. We bought many of our tools and overhaul equipment on the surplus market. Those we could not get, we redesigned and built better ones.”

Future of the radial engines

I asked Seeman and Abbott for an opinion on the future of the R-985 and R-1340 radial engines. They say that “for engines designed in 1920s, they are still very reliable, probably more so today. Improvements in the design and materials for seals and gaskets have reduced oil leaks and dried the engine up. As for longevity, it is all about economics. The agribusiness operators will fly these engines as long as it is profitable to do so.”

Pratt & Whitney no longer produces its famous Wasp engines but there are at least five companies building radials today. Rotec Engineering Pty. Ltd. in Victoria, Australia, is producing the Rotec R2800 (a 110-horsepower seven-cylinder engine) and the R3600 (a 150-horsepower nine-cylinder engine). And, Verner Motors in the Czech Republic is building a modern five-cylinder radial.

It appears that these remarkable engines will be around for some time. There are operators using them, hobbyists flying them, and mechanics taking pride in maintaining them. This is very good news for the romantics among us. There are some sounds that we hope never fade away, like birds singing in the spring, straight pipe Harleys, 440 hemis, and radials turning over on a cold morning. 

Charles Chandler is an A&P based in Michigan. He received his training from the Spartan College of Aeronautics.