Harley Builds a Rocket: Harley-Davidson’s LR-64 Navy Rocket Engine
Harley-Davidson built more than motorcycles. One of the strangest examples came from a U.S. Navy target-drone contract that put Harley-Davidson’s York, Pennsylvania operation into the business of building liquid-fueled rocket engines.
That sounds like a joke, but the LR-64 was real. It powered the AQM-37A “Jayhawk,” a supersonic target drone built by Beech Aircraft to help the military simulate missile threats. Most of Harley-Davidson's history centers on motorcycles, but the LR-64 shows how far the company’s defense-contract work could reach.
Harley-Davidson, York, and the LR-64 Contract
The original story is simple enough to sound unbelievable: Harley-Davidson had a U.S. Navy contract to build rocket engines. The program appears to have roots before AMF bought Harley-Davidson, and production continued after the acquisition, with LR-64 engines built alongside motorcycle-related work tied to the York, Pennsylvania plant.
The work overlapped the final production years of the XLA Sportster, Harley-Davidson's postwar U.S. Army patrol motorcycle, but it belonged to a very different kind of defense contract.
This was not a motorcycle engine adapted for flight, and it was not a showroom product with a Bar & Shield decal slapped on it. The LR-64 was a purpose-built liquid-fueled rocket motor for a military target-drone system. It is one of the stranger industrial side roads in Harley-Davidson history, much like Harley’s Jeep prototype work, where the company’s name turns up in a place most motorcycle people would not expect.
The AQM-37A Jayhawk Target Drone
The LR-64 engine was used in the AQM-37A “Jayhawk,” a Beech Aircraft target drone built to fly at supersonic speeds. Its job was not to carry a rider or a pilot. It was launched as a target so military crews and weapons systems could train against missile-like threats.
Some AQM-37A variants were fitted with parachute recovery systems so they could be recovered after flight. That detail is easy to overlook, but it explains why a high-speed target drone could also be treated as a reusable test asset in some versions rather than a one-shot piece of hardware.
Storable Propellants and a Dangerous Little Rocket Engine
The LR-64 used storable liquid propellants. The advantage was practical: the drone did not have to be fueled immediately before every flight. That made it useful for military testing because the system could be prepared and held ready in a way that would have been harder with propellants that had to be loaded at the last moment.
The downside was serious. The propellants were toxic and corrosive, and the fuel-and-oxidizer combination was hypergolic, meaning it ignited on contact. That is convenient inside a rocket engine and unpleasant everywhere else. It was the kind of system that demanded careful handling, not the kind of thing anyone would want to treat like gasoline, oil, or a shop rag.
More Than 5,000 Harley Rocket Engines
Harley-Davidson produced more than 5,000 of these rocket engines, with LR-64 production running from the mid-1960s into the 1990s.
That long run is what makes the story more than a novelty. Harley-Davidson’s rocket-engine work was not a one-off experiment or a single publicity photograph. It was a real production contract that put the company’s manufacturing name into the Navy target-drone world for decades.
AQM-37A / LR-64 Specifications
Here are the dimensions and powerplant information for the AQM-37A target drone with its Harley-Davidson LR-64 rocket engine:
- Length: 14 ft 0 in (4.27 m)
- Wingspan: 3 ft 4 in (1.00 m)
- Height: 2 ft 2 in (0.66 m)
- Gross weight: 620 lb (280 kg)
- Powerplant: 1 × Harley-Davidson LR-64 liquid-fueled rocket, 850 lbf (3.78 kN)
They are not exactly “Harley orange,” but still look pretty good. Maybe just add some chrome and a custom paint job...