UAV Roadmap

On Monday, I posted the blog entry Why "My Other Vehicle is Unmanned"? which mentioned the regulatory challenges facing the development of Unmanned Aircraft Systems (UAS) and their introduction into civil airspace.

On Wednesday, Lockheed Martin announced in a press release that it has been selected by the Federal Aviation Administration (FAA) Unmanned Aircraft Program Office to assist in the development of a roadmap for US government and industry UAS initiatives. The press release contains a couple of very significant sentences, these are:

By applying its technical, programmatic and specialized expertise in air traffic systems and airspace operations, Lockheed Martin will evaluate the current state of UAS mission needs, forecast their near-term demands on airspace capacity and chart a strategic plan to safely integrate their operations into the nation's airspace.

and:

"By identifying the mission needs, operating environments and platforms expected for unmanned aircraft, and then mapping them against manufacturer plans and FAA certification timelines."

These statements are important because they indicates that the collaboration between the FAA and industry (through Lockheed Martin) will seek to address the complex issue of UAVs (military included) operating in civil airspace.

Until now, military UAVs have operated in segregated airspace, which can come as a surprise to some people, as it is easy to assume that UAVs have been sharing airspace with civil aircraft. Two instances which I am aware of, both relating to UK airspace, include the flight of US Global Hawk UAV from Edwards, AFB California to Nordholz Germany on 14-15th October 2003 through dedicated temporarily segregated UK airspace; and the first flight of the  Watchkeeper UAV in the UK in September 2005 (which was announced in a Thales press release) actually used temporarily segregated airspace with an air-exclusion zone around the airfield (this was reported by the UK Civil Aviation Authority at the Unmanned Systems International conference which I attended later the same week).

However, as the desire to expand their roles has grown, this has inevitably led to the prospect of commercial aircraft and unmanned systems operating in the same airspace. This raises a number of key issues, not just in terms of technical integration, but also in terms of aircraft and passenger safety, but also that  of public perception and acceptability. People readily accept the idea purveyed by science fiction movies of autonomous unmanned systems flying around airspace and space, but are they ready to accept semi-autonomous unmanned systems flying in the same airspace as their passenger flight in the very near future?

This matter is further complicated by the fact that the FAA is currently only responsible for the safety certification of civil aircraft through a number of safety standards and guidelines - software is address by RTCA DO-178B in the US (and there is the direct equivalent EUROCAE ED-12B in Europe). In the past, the safety certification of software on military aircraft was undertaken to military software standards, but in recent years, the DO-178B has become increasingly adopted for military systems (and the influence of DO-178B around the world is very much in evidence).

What levels of safety certification will be imposed on the software systems for UAVs wishing to fly in civil airspace? It's not clear yet, although the phrase 'Equivalent Level of Compliance' is sometimes mentioned. In addition, aerial collision avoidance and terrain clearance methods have not been agreed yet.

The uncertainty around the safety certification requirements poses a risk for manufacturers embarking on new UAV developments, as they cannot determine at the outset of their programme what the final safety certification requirements will be for individual UAV subsystems, such as the flight control system, ground link, mission systems, etc. However, this risk could be mitigated through the use of a COTS standards-based safety-critical software platform (as is advocated by the Device Software Optimization (DSO) philosophy).

In the future will the FAA become involved in the certification of all UAVs which wish to fly in US civil airspace (military or not)?

Comments

[George Romanski]

DO-304, Guidance Materials and Considerations for Unmanned Aircraft Systems, was published by RTCA on March 22, 2007. It answers some of the questions, many more still remain.

[Paul Parkinson]

George,

Thanks for the feedback! It's good to see that things are moving forward in this area. I'll look forward to reading DO-304.