During World War II, the United States Army Air Forces obtained three ERCO Ercoupe model 415‑C aircraft for testing and evaluation, each with its own military designation and serial number.
The goal was to see if the civilian Ercoupe—famous for its stall‑ and spin‑resistant design—could be adapted for roles like observation, liaison, training, or target drone development.
The first, construction number 39 (NC28944), purchased on January 4, 1941, was designated YO‑55 with serial number 41‑18875 and tested mainly as a light observation platform.
Despite excellent handling, it lacked the ruggedness and payload for operational use.
Ercoupe XPQ-13
The second, construction number 110 (NC37143), bought on August 14, 1941, became PQ‑13, serial number 41‑39099, serving as a radio‑controlled target drone prototype and later earning historical significance as the only surviving warbird‑designated Ercoupe.
The third, construction number 11 (NC28655), acquired on December 4, 1940, was also redesignated PQ‑13, serial number 41‑25196, used for target‑drone experiments and later instructional purposes.
Notably, one PQ‑13 played a key role in early rocket‑assisted takeoff trials: on August 12, 1941, at March Field, California, Captain Homer Boushey conducted the first U.S. JATO experiment with an Ercoupe, proving that small aircraft could benefit from rocket propulsion and paving the way for future jet‑assisted flight and missile advances.
