Question: The American Aircraft Penetrator was modified from a helicopter produced by what nation's military?
Related documents: [0]  [DOC] The Bell UH-1 Iroquois (nicknamed "Huey") is a utility military helicopter powered by a single turboshaft engine, with two-blade main and tail rotors. The first member of the prolific Huey family, it was developed by Bell Helicopter to meet a United States Army's 1952 requirement for a medical evacuation and utility helicopter, and first flew in 1956. The UH-1 was the first turbine-powered helicopter to enter production in 1960 for the United States military, and more than 16,000 have been built since. [END] 
[1]  [DOC] The American Aircraft Penetrator, now referred as the Aerocraft Stealth Star 204 SS, was a gunship helicopter modified from the Bell UH-1B Iroquois with tandem seating for the pilots and a troop-carrying compartment. [END] 
Answer: 
United States
United States