Comment Comment by krisoft The FAA's 1995 Airship Design Criteria report says: "The lifting gas must be non-flammable."Page 44: https://www.faa.gov/sites/faa.gov/files/aircraft/air_cert/de... parent krisoft 3 years ago
Page 44: https://www.faa.gov/sites/faa.gov/files/aircraft/air_cert/de...