Novel airspace systems that integrate the latest technology advancements must be tested before widespread adoption. Despite the growing sophistication of simulation software, new systems must be practically tested before implementation. To facilitate the rapid prototyping of such architectures we present the flight test results of a low cost, small scale, modular airspace design. We incorporate flight data processing and control logic into an onboard iPhone 4 in small UAV aircraft. The iPhone 4 performs guidance, navigation, and control, while receiving desired trajectory information from a ground based laptop. We integrate these aircraft into a simulated air traffic environment and demonstrate automated two-way communications between aircraft and ground control tower. We present results of successful straight and level flight and trajectory tracking for a single aircraft.