The Packard XJ41 was a

turbojet The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, an ...

aircraft engine developed by the Packard in the mid-1940s.

Design and development

In 1943, Packard leased a government-owned manufacturing plant located on the outskirts of

Toledo, Ohio Toledo ( ) is a city in and the county seat of Lucas County, Ohio, United States. A major Midwestern United States port city, Toledo is the fourth-most populous city in the state of Ohio, after Columbus, Cleveland, and Cincinnati, and according ...

. The plant was previously operated by the defunct Aviation Corporation. Packard used the leased plant to manufacture parts for the

Rolls-Royce Merlin The Rolls-Royce Merlin is a British liquid-cooled V-12 piston aero engine of 27-litres (1,650 cu in) capacity. Rolls-Royce designed the engine and first ran it in 1933 as a private venture. Initially known as the PV-12, it was late ...

engine, and referred to it as its Toledo Division. In the early-summer of 1944, the Army Air Force Materiel Command contracted with Packard to carry out "advanced aircraft engine development" on both the Merlin and gas-turbine engines. To oversee the new project, Packard hired

Allison Engine Company The Allison Engine Company was an American aircraft engine manufacturer. Shortly after the death of James Allison in 1929 the company was purchased by the Fisher brothers. Fisher sold the company to General Motors, which owned it for most of it ...

's Robert M. Williams as their chief design engineer at the Toledo facility in July of that year. In early 1945 the Power Plant Lab at

Wright Field Wilbur Wright Field was a military installation and an airfield used as a World War I pilot, mechanic, and armorer training facility and, under different designations, conducted United States Army Air Corps and Air Forces flight testing. Lo ...

asked Packard to take on a research project to develop an expendable jet engine of , weighing no more than . Design work for the engine, designated Packard XJ41, began in May 1945. After studying existing turbojet engines it was decided to design an engine which would be a significant advancement over conventional turbo-jet engines, have a low manufacturing cost, minimum use of strategic materials and be a lightweight design. The Packard XJ41 met those requirements with a combination of a

mixed flow compressor A mixed flow compressor, or diagonal compressor, combines axial and radial components to produce a diagonal airflow compressor stage. The exit mean radius is greater than at the inlet, like a centrifugal design, but the flow tends to exit in an axi ...

, a lightweight

annular Annulus (or anulus) or annular indicates a ring- or donut-shaped area or structure. It may refer to: Human anatomy * '' Anulus fibrosus disci intervertebralis'', spinal structure * Annulus of Zinn, a.k.a. annular tendon or ''anulus tendineus co ...

combustion chamber A combustion chamber is part of an internal combustion engine in which the fuel/air mix is burned. For steam engines, the term has also been used for an extension of the firebox which is used to allow a more complete combustion process. Intern ...

and hollow turbine blades for both rotor and stator. The engine's most outstanding design characteristic was the use of an air inlet that operated at

supersonic speed Supersonic speed is the speed of an object that exceeds the speed of sound ( Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater than five times ...

that produced more thrust per pound of weight than designs using low-velocity inlet air. The XJ41 weighed and produced , where the

Allison J33 The General Electric/Allison J33 is a development of the General Electric J31, enlarged to produce significantly greater thrust, starting at and ending at with an additional low-altitude boost to with water-alcohol injection. Development Th ...

weighed at the same thrust. The XJ41 was completed and operating on a test stand by January 8, 1946. Packard's investment for production of the new turbojet engine design was extensive. By the end of 1946, the installation of fabrication and testing equipment was valued at $10,000,000. In addition, flight testing, shop, and hangar facilities at Willow Run, Michigan was valued at $1,000,000, and an additional $3,500,000 in laboratory and testing equipment was installed by spring of 1947. Serial numbers V-500001 to V-500007 were allocated, indicating that at least seven engines were built. Development continued on the engine over three years, with Packard assigning model numbers PT-103 and PT-104 to military engine designations XJ41 serial number V-500001 and XJ41 serial number V-500003. A design study for an engine suitable for high acceleration, such as a catapult launched take-off, was assigned model number PT-106 in February 1947. Between September 1947 and July 1948 an XJ41 was flight-tested several times attached to a North American B-25J Mitchell bomber. Development of the XJ41 stopped when Packard engineers came up with a radical redesign that differed so much the designation XJ49 was assigned. All work on the XJ41 stopped and funding was transferred to the new design.

Specifications (XJ41-V-500003)

References

;Notes ;Bibliography *

External links

Packard Aircraft EnginesPackard engine specificationsImages of Packard engines including the XJ41Production statistics for all Packard engines
{{Aeroengine-specs 1940s turbojet engines XJ-41

Design and development

Specifications (XJ41-V-500003)

See also

References

Further reading

External links