Honeywell caused a stir recently when it announced its development of a system that would automatically take control of an aircraft if the pilots fail, or refuse, to prevent a crash. Called the Auto-Avoid System, this new development is meant as an advancement to Honeywell’s popular enhanced ground proximity warning system (EGPWS). It would go beyond warning pilots of a potential controlled flight into terrain (CFIT) or an obstacle, however. Absent an appropriate response from the cockpit, it would signal the aircraft’s flight control system, via an ARINC 429 bus, to initiate an evasive maneuver. The Auto-Avoid System would return control to the pilots immediately after determining that the aircraft is on a safe flight path.
I refer to "pilots," but it also could protect the aircraft against unwanted occupants of the cockpit. Honeywell began developing the Auto-Avoid System before Sept. 11, 2001, solely with pilots in mind. But since that tragic day, the technology has attracted further interest as a way to prevent terrorists from turning airplanes into guided missiles. The system’s original purpose, according to Honeywell, was to compensate for a pilot’s delayed reaction to an EGPWS alert. But it could prevent a deliberate act, too. And this could apply to suicidal pilots, as well as terrorists. Pilot suicide is the suspected cause of several airline tragedies, including the 1999 crash of EgyptAir flight 990.
Boeing and Airbus have been working with Honeywell on the Auto-Avoid System, but they haven’t endorsed the technology. So, although it is being flown in Honeywell’s King Air C90, a full-up system probably will not be installed in commercial aircraft soon. Indeed, the Auto-Avoid System’s certification could take years, as its software would first have to be approved to the stringent DO-178B, Level A, standard. (EGPWS must meet only the Level C standard.) A Honeywell spokesman says the company may adopt a progressive certification plan, in which a system with manual override would be approved prior to a full-up, "hardened" system that would not allow override.
But, in addition to certification hurdles, the hardened Auto-Avoid System faces a user community that is cool to the idea of airliners suddenly becoming unmanned air vehicles (UAVs), even for brief periods of time. An Airbus spokesman says: "The result of such a system will not be to take the pilot out of the loop. The basic principle is that pilots remain in control of the aircraft at all times." Likewise, an official with Boeing commented that, in his company’s aircraft, "Pilots would have the capability to turn off the system. This is consistent with the time-proven Boeing Commercial Airplane philosophy that pilots fly airplanes, not computers."
Pilots agree with this sentiment. When asked of the pilot’s view of the Auto-Avoid System, John Mazor, spokesman for the Air Line Pilots Association, said flatly: "We’re not thrilled. We like EGPWS. Pilots want all the information they can get. But when you can’t turn a system off and the airplane starts to behave like the HAL 9000 [computer] in the movie ‘2001,’ then we have a problem."
Defending the Auto-Avoid concept, Don Bateman, Honeywell’s chief engineer-flight safety systems, says automation has long been used to keep aircraft within a safe flying envelope. Regarding a manual override, he says, "We’ve had stability augmentation for years, and I don’t think pilots would want to turn that off.
"As long as the aircraft is flown in a safe manner, this system is transparent," Bateman contends. "But if you fly where you don’t belong, then it will keep you out of trouble." In addition to terrain and obstacles, the Auto-Avoid system could be programmed to prevent flying into restricted airspace.
The pilots’ concern that they are losing control of the aircraft is understandable. Last month, for example, we reported on the Automatic Air Collision Avoidance System, developed by a Lockheed Martin-led team (September 2003, page 11). Like the Auto-Avoid System, it is designed to be a "last ditch" collision avoidance system, but it prevents midair crashes, not CFIT.
Ultimately, pilots will have to accept the fact that their responsibilities are changing–but not diminishing. For instance, armed with more information and greater situational awareness, pilots will assume more strategic decision-making functions and will coordinate with air traffic controllers, rather than submit to their direction.
The Auto-Avoid System would seem to be a welcome enhancement to EGPWS, a proven safety device installed in more than 18,000 aircraft. As for a hardened Auto-Avoid System, user reluctance aside, one would hope that with more vigorous passenger screening, bullet-proof cockpit doors, cabin surveillance cameras, pilots armed with guns, and scrupulous reviews of pilot profiles, such a system would not be needed.