Lockheed Model 89 (Wiki)
Most of the material presented here comes from the U.S. National Archives at College Park, Maryland and is part of Record Group 72, Entry 145, Box 3.
Lockheed Model 89 Turbosupercharger Trade Studies
Compiled by Kimble D. McCutcheon
Published 12 Jun 2025; Revised 23 Jun 2025
Lockheed Model 89 (Wiki) |
Early in 1942, the Lockheed Aircraft Corporation of Burbank, California began considering a large transport airplane, the Model 89. Possible customers included the U.S. Navy, which was interested in expanding its fleet of land-based transport aircraft to supplement its flying boat transports. Pan American Airways was also interested in the Model 89 as a commercial airliner. Using four Pratt & Whitney Wasp Major (R-4360) turbosupercharged engines to operate at a 25,000 ft cruising altitude, Lockheed was keen on an efficient turbosupercharger selection and installation. Lockheed studied three turbosuperchargers: an in-house design, a traditional General Electric unit, and a new offering from the Turbo Engineering Corporation. The trade studies documenting this selection process are summarized in this article.
Most of the material presented here comes from the U.S. National Archives at College Park, Maryland and is part of Record Group 72, Entry 145, Box 3. |
12 Jun 1943
Lockheed Report No. 4217. Comparison of General Electric and Lockheed Turbosuperchargers.
14 Sep 1943
Lockheed Report No. 4342.
Preliminary Specification for Exhaust-Driven Turbosupercharger.
This specification covered the Lockheed turbosupercharger design.
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| Sketch 89-474 – Fig. 5 | Sketch 89-298 |
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| Sketch 89-473, Fig. 6 End View | Sketch 89-473, Fig. 6 Side View | Sketch 89-473, Fig. 6 Plan View |
14 Sep 1943
Lockheed Report No. 4360.
Turbosupercharger Design for a Transport Airplane.
This provides details of the Lockheed turbosupercharger.
17 Mar 1944
Lockheed Report No. 4575. Preliminary Specification for Turbosupercharger.
This specification covered the General Electric turbosupercharger.
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| General Electric Type BT Turbocharger Installation Details | |
4 Mar 1944
Lockheed Report No. 4651. Comparison of Turbosuperchargers for Model 89.
This report compares the Turbo Engineering Corporation and General Electric turbosuperchargers.
4 Oct 1944
Lockheed Report No. 4916. Preliminary Specification for Turbosupercharger.
This was the final turbosupercharger specification after Lockheed, General Electric and Turbo Engineering products had been considered.
Lockheed Model 89 Characteristics and Performance
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| Lockheed XR60-1 Landing at Moffett Field, California (Wiki) |
Lockheed XR60-1 Airplane Characteristics and Performance, 1 Jun 1944
Lockheed XR60-1 Airplane Characteristics and Performance, 1 Jan 1947
Lockheed XR60-1 Constitution Standard Aircraft Characteristics, 1 Apr 1949
Conclusion
When all was said and done, Lockheed selected General Electric BH-3 turbosuperchargers for its Model 89. These were a development of the Type BT, whose test results appear in this article. As was a common engineering trend, Lockheed did not chose what worked best, but what worked first and was available off the shelf.
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