Massive multiple-input multiple-output (MIMO) technology will continue playing an important role in beyond 5G wireless systems. Fully digital beamforming at the millimeter wave (mmWave) spectrum enables applications that require high data rates and low latency. This paper investigates the development and deployment of mmWave massive MIMO systems in an in-flight cabin environment, from both system performance and hardware implementation aspects. Ray-tracing methods with realistic geometry coefficients captured from commercial airplane models are used to represent this in-door dense environment. A hardware-in-the-loop simulator running on the AMD/Xilinx PYNQ FPGA is leveraged to conduct fast design space exploration. The outcomes of our investigation provide insights and guidelines in strategies for implementing and deploying mmWave massive MIMO systems in-flight cabins, for instance, how to place and distribute access points to enhance coverage and serve quality and the appropriate quantization strategy balancing hardware cost and signal processing quality.