Just how many hours can you wring from an airplane? As the operators, mechanics, and parts suppliers who keep DC-3s in the air.
- By Mark Huber
- Air & Space magazine, May 2000
(Page 3 of 5)
Precision Engines in Everett, Washington, is one of the world's most respected overhaulers of radial piston engines. It holds FAA Parts Manufacturing Authority for over 1,200 Wright and Pratt & Whitney radial engine parts, including those for the R-1830 Twin Wasp, the engine used on most DC-3s. (Wright engines powered some early DC-3s; however, the R-1830 showed up in 1936, and all C-47s used it.)
Every other year Precision sponsors the World Radial Engine Symposium in an effort to answer customer questions and urge proper maintenance and operating procedures. The last symposium attracted 120 participants from around the globe. While some were hobbyists and warbird buffs, the vast majority were revenue haulers. One of them was Don Elliott, the director of maintenance for Miami Valley Aviation and its fleet of six DC-3s.
"They take a lot of oil," says Elliott, who was reminded at the symposium of one of the things he experiences almost daily in the field: With oil starvation the chief engine killer, the engines must be pre-oiled before each flight. An electric motor is used to pump oil into the engine before it's started. Even with this precaution, only 50 percent of the engines will run without help for 1,400 hours, the FAA's "Recommended Time Between Overhauls" for the R-1830.
"Our new pilots don't believe me when I tell them, on average, they will shut down an engine in flight every 500 hours," says Miami Valley's Kevin Uppstrom, who has more than a little experience with single-engine DC-3 flying. Then, of course, there's the natural temptation to push the remaining engine too hard, which often results in its failure on the next flight out, according to Uppstrom.
"I've pulled 'em off everywhere I can think of," says Elliott. "We've got it down to a science."
Premature engine death can boost DC-3 hourly operating costs into the range incurred by a light corporate jet and is the main reason virtually all operators using the airplane for passenger service or sightseeing rides have abandoned it. (Freight operators can generally charge more and therefore survive the economic bite inflicted by unpredictable engine life.) An R-1830 engine that is lovingly coaxed to its overhaul time usually costs around $30,000 to rebuild. Salvaging one that scatters from abuse starts at $45,000.
"The engine situation is what's killing the airplane," says historian Henry Holden. "There comes a point [after multiple overhauls of the same engine] that you just can't get pressure out of the cylinders anymore."
Somehow, the DC-3 labors on. "Ten years ago, I would have said they're going to be gone in ten years," says Miami Valley's Don Elliott, whose company flies freight in a $2 million Falcon 20 jet and four Beech 18s; it also owns two Learjets, a King Air 200, and three Piper Aztecs. "The DC-3s have bought us everything we have here," says Kevin Uppstrom, and Elliott agrees.