Boeing B787 network certification requirement

Greetings, folks. I am Peter Ladkin and hope to be contributing on safety matters, especially in transportation.

Bob wrote recently about the FAA's new certification requirement on the Boeing B787 "Dreamliner" networks. I checked it out.

The FAA makes regulatory requirements (which are administrative law) by publishing a Notice of Proposed Rulemaking (NPR) in the Federal Register (FR) , collecting comments, and implementing the rule in the light of comments. The NPR was published in FR 72(71) on April 13, 2007, eight months ago. The FAA received comments from Airbus and from the Air Line Pilots Association, and issued the rule, unchanged, with answers to the comments, in FR 73(1) on January 2, 2008, whence the brouhaha in Wired.

So far, this all looks routine. Let's look at what the rule does.

There are three "domains" for networks in the B787: the Aircraft Control Domain (ACD), the Airline Information Domain (AID) and the Passenger Information and Entertainment Domain (PIES). The ACD is the safety-critical bit. The PIES is the passenger network. The rule says "the design shall prevent all inadvertent or malicious changes to, and all adverse impacts upon, all systems, networks, hardware, software, and data in the Aircraft Control Domain and in the Airline Information Domain from all points within the Passenger Information and Entertainment Domain." It is harder to get any more stringent than that.

Why are the FAA doing this now? Because they have perceived a gap in existing regulation which needs to be filled. And it needs to come now because Boeing are certifying the aircraft now. Airbus wanted more generally applicable conditions along with guidance on how to comply. The FAA replied that they are working on that, but the B787 needs it right now.

A colleague suggested the least expensive way of fulfilling this criterion might be to separate the domains physically. Well, I am not sure that can be done, since some of the AID as well as PIED are wireless. In some current fleets, for example, sensor data and other data in the aircraft control networks is siphoned off to go to, amongst other things, the Quick Access Recorder (QAR), which records data on the flight for airline flight quality control and maintenance. At least one major airline downloads the QAR data at the end of each flight directly through the local cell phone network at the destination. So one already has potential interconnections between public networks and aircraft control networks in which all the bad stuff must be controlled (and is, by obvious means).

Why aren't the FAA requiring similar for ACD/AID interaction? They are; they say this is covered by existing regulation as well as other special conditions (which I haven't yet seen).

So this looks all routine admin stuff. I don't see anything below the surface. Except, of course, for the monster question of how one does assure absolute security of the sort that looks to be required. I don't know who can answer that question, and I doubt if Boeing's answer will enter the public domain.


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