Certification of Unmanned Aircraft Systems

One of the most discussed topics today in the Aerospace Industry is the Unmanned Aircraft System (UAS) and its possibilities of operating within commercial airspace. A UAS includes ground command & controls, communication stations & links, and Unmanned Aircraft Vehicles (UAVs). The UAVs are controlled remotely, autonomously, or by a combination of both methods. Currently, five categories or classes existed for UASs, which include the following:

	Micro		Mini		Short Range
	Tactical		High Altitude

UAS Considerations

Although there has yet to be an FAA mandate for UAS/UAV Safety-Critical Software and Electronic Hardware certification, a System Safety Assessment may result in the determination that there are Safety-Critical subsystems on the UAS, which could include:

• Flight Controls (Air and Ground)
• Sense and Avoid
• Command/Control/Communications
• Navigation and Surveillance

Software and Electronic Hardware used in Safety-Critical subsystems should be developed using process guidelines that will ensure the following:

• Software/Electronic Hardware performs its intended functionality.
• Software/Electronic Hardware responds deterministically to all input conditions, including unintended or unexpected stimuli.
• Requirements are captured and reviewed for system safety assessment and validation at the Customer, Functional, and Design/Architecture levels.
• Requirements are verified for normal range and robustness conditions.
• No dead code, no unexecuted code, no non-deterministic behavior, etc.

UAS Certification Guidelines

The ultimate question thus becomes, "What certification standards are available for a Safety-Critical UAS?" In 2007 the RTCA created and published DO-304 Guidance Material and Considerations for Unmanned Aircraft Systems. This document addresses all UAS and UAS operations being considered for realistic implementation in the U.S. National Airspace System (NAS) in the foreseeable future. It's intended to educate the community and be used to facilitate future discussions on UAS standards. For Safety-Critical Software and Electronic Hardware certification the RTCA has publish both DO-178B Software Considerations in Airborne Systems and Equipment and DO-254 Design Assurance Guidance for Airborne Electronic Hardware standards, which apply to manned aircraft. These standards could easily be applied to any UAS being developed today to ensure that Safety-Critical Software or Electronic Hardware meet current conditions brought forth by the FAA for manned aircraft operating in the NAS.