Turbine-Charged
Since 1990 Basler Turbo Conversions has given new life to dozens of DC-3s.
- By Mark Huber
- Air & Space magazine, May 2000
The hulks of seven DC-3 fuselages are parked alongside Basler Turbo Conversions' 75,000-square-foot facility in Oshkosh, Wisconsin. Three more DC-3s sit inside, disemboweled, bracketed by yellow scaffolding in a main hangar that looks like a surgical theater. With them, a shiny white and blue BT-67, a "Basler-ized" DC-3, awaits its new owner. Fly-away price: about $4 million.
Since 1990 Basler has given new life to dozens of DC-3s. (In the 33 years prior to that, Basler Flight Service had reworked more than a hundred DC-3s, modifying interiors, restoring airframes, and overhauling engines.) Basler installs Pratt & Whitney Canada PT6A-67R turboprop engines and Hartzell five-blade metal propellers in place of the piston engines and props that powered the original aircraft. The company increases the DC-3's volume 35 percent by inserting a 40-inch plug in the fuselage forward of the wing and moving the cabin bulkhead forward five feet. A BT-67 boasts 45 more mph of cruise speed and almost 4,000 more pounds of useful load than the original DC-3.
The aircraft's notoriously temperamental 14-cylinder piston radial engines have always been seen as its weakest feature, so hanging turbines on DC-3s is not a new idea. The British tried it at the end of the 1940s using Armstrong-Siddeley Mamba and Rolls-Royce Dart turboprop engines. The engines helped, but the unpressurized aircraft couldn't be flown at an altitude that would use the engines to their best advantage, and the project was quickly dropped. The idea was resurrected in the 1960s: In California, a few "Super Turbo Threes" were made and sold, but that project also fizzled. A Taiwanese venture failed as well.
One of the most interesting turbo conversions was done by aviation legend Jack Conroy in the 1960s. His modified DC-3 initially featured three Dart engines, two on the wings and one stuffed in the nose. He sold the airplane to the Specialized Aircraft Corporation, which replaced the engines with Pratt & Whitney models. DC-3 experts then trace the Tri-Turbo to Santa Barbara Polair, Inc., which leased it to the U.S. Navy as a ski-equipped arctic research aircraft. Some have suggested it flew missions for the CIA. The late Warren Basler bought the aircraft in 1992 from a salvage yard in Tucson. It was so distinctive that Basler insisted it be preserved as an important part of the DC-3's history, and today it sits in Oshkosh, stripped and weathered, awaiting rebirth.
In addition to converting the engines and extending the fuselage, Basler installs new electrical, hydraulic, and fuel systems, reinforces the wings and fuselage to handle the aircraft's increased gross weight, upgrades avionics to current standards, and modifies the wingtips and the leading edges on the outboard sections of the wings to improve stall characteristics. A fully loaded BT-67 has a slower approach speed than a comparably loaded DC-3.
Basler will convert an owner's existing airframe or provide an airframe for conversion. In the latter case, the company looks for "low-time" (less than 40,000 hours) airframes with relatively little corrosion and a good maintenance history. Some are trucked in. Corroded parts are replaced. A Basler-converted airframe is considered to have "zero time" with respect to mandated inspections.
The company fitted five BT-67s in gunship configuration with forward looking infrared (FLIR) cameras that could be slaved to .50-caliber machine guns and sold them to the Colombian air force to fly drug interdiction missions. The government of Mali has used its BT-67 to transport U.N. Secretary-General Kofi Annan to Timbuktu. And last year a freshly minted BT-67 on skis began flying adventurers to Antarctica. Other Basler conversions fly a variety of missions around the world: Six are used for rainmaking in Thailand, and two are flown by the U.S. Forest Service to drop smokejumpers in Montana. The Basler operation has become so well known that the company constantly gets calls from DC-3 operators looking for parts.
The major modifications that Basler makes to the DC-3s are done under a Supplemental Type Certificate. The FAA has also granted the company Parts Manufacturing Authority for the parts it manufactures in-house. A substantial part of the PMA is related to the new electrical and fuel systems. The FAA's Manufacturing and Inspection District Office has manufacturing oversight.
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