Dear Editor:

On January 23rd, 2003, the 91-year-old 1948 Indianapolis 500 veteran and founder of the U.S. Truck Driving School, Johnny Mauro, drove the wrong way down Interstate 70, causing a head-on collision in Denver that killed himself and 17-year-old Christopher Basinski. Obviously, the teenager shares no blame in the head-on accident because the whole point of head-on collision safety is that heroic last-minute warnings and heroic last-second evasive maneuvering are extremely poor alternatives to preventing a head-on collision possibility in the first place. That is why interstate highways are designed to eliminate head-on collisions conflicts with separate traffic lanes protected by concrete guardrails and signs to eliminate head-on conflicts so that heroic warnings and evasive maneuverings are not required.

To assist drivers in obeying this principle, big red "Wrong Way" or "Do Not Enter" signs are posted at all interstate highway exit ramps to warn drivers like Mauro away from inadvertently driving into head-on traffic. If Mauro had ignored such a sign, he'd be at fault in the accident. If vandals had removed the sign that Mauro had driven past, that crime would have made them morally compromised and legally vulnerable within the criminal courts. If a highway maintenance contractor had temporarily removed the signs and forgotten to replace them, the contractor would have been vulnerable to civil damage claims by the Mauro and Basinski families. If the Colorado Highway Department had never even put up the signs in the first place, then the state could be morally, if not legally, challenged for failing to incorporate the state-of-the-art in highway safety design and common practice for preventing head-on collisions. When the highway laws are obeyed on interstate highways, head-on collisions are impossible by design.

Paradoxically, the Federal Aviation Administration (FAA) has for over 30 years refused to incorporate the most effective published state-of-the-art flight safety technique for keeping aircraft from having head-on collision paths in the first place (See Air Facts, Feb. 1968 [1 Mb download]). Instead, the FAA relies upon voluntary compliance with technically inadequate recommendations and risk multiplying regulations (see Risk Analysis: An International Journal, March 1997 [60 kb download]), occasionally failing electronic equipment, workload-permitting last-minute warnings from air traffic controllers and heroic last-second maneuvering by pilots to avoid midair collisions like the one over Denver on Friday, January 24. In this case, a southbound Piper Cheyenne crashed into a northbound Cessna 172 (headed, ironically, for Cheyenne, Wyoming). While the Piper's altitude encoding altimeter measurement was not showing on the controller's radar display, this electronic failure is somewhat irrelevant for systematically preventing such accidents. By law, the pilots were not required to even be talking to Air Traffic Control (ATC), although both pilots had opted to ask for traffic following from the same controller. By law, ATC was not required to provide traffic advisories, because this service is only offered on a workload-permitting basis. By law, ATC had no responsibility for the midair collision over Denver, because a subtle revision to Federal Aviation Regulations after the Cerritos, California midair collision now places 100 percent of the responsibility for collision avoidance on pilots (IFR or VFR) flying in visual meteorological conditions. Legally, ATC personnel could have knowingly looked right at perfectly painted radar images of the VFR Cessna and Piper, even with accurately reported altitude displays, without saying anything, and without having any responsibility for an inevitable midair collision. This is not a valid midair collision avoidance safety system. In contrast to highway safety system design, when all the laws are obeyed in the air, head-on collisions are still inevitable, even to the point of being encouraged by the laws (see Risk Analysis: An International Journal, March 1997 [60 kb download]).

The proven technique being ignored by the FAA [100 kb download] is what I call the Altimeter-Compass Cruising Altitude Rule (ACCAR). Adopting this rule would have undoubtedly given pilots Jonathan Ladd and Leo Larson a useful tool for avoiding each other over Denver, even if they never looked out the window, and even if they had opted out of using the voluntary traffic-safety advisories offered (only on a workload-permitting basis) by Air Traffic Control. Adopting ACCAR cost nothing to pilots and aircraft owners because all aircraft are already required by law to have an altimeter and compass for even the most basic flight operations. The 30-year-old ACCAR idea requires a pilot's imagination (or a see-through sticker on the altimeter glass) to mentally superimpose a north-south-east-west compass directions scale on top of the altimeter scale. The ACCAR pilot then flies in a direction and at an altitude such that the "compass heading" angle of the 100-ft needle on the altimeter matches the actual magnetic compass heading of the aircraft. [50 kb] By design, when all pilots use ACCAR for level flying as much as possible, then all pilots at every altitude are flying parallel paths that never cross--and all head-on traffic is automatically separated by 500 feet of vertical clearance. This is a huge philosophical difference compared to the hemispherical cruising altitude rules where, by design, aircraft with a compass heading of 181 degrees are required by law to have head-on collision paths with aircraft on a heading of 359 degrees. ACCAR minimizes collision probability while simultaneously maximizing the time that a collision-threatening aircraft is visible to pilots in danger (see Figures 1 and 2 in Risk Analysis) . This amount of separation would have saved five lives and two homes last week in Denver. It would have also saved 71 lives lost over Germany July 1, 2002, and would have greatly increased the margin of safety involving 427 who almost died Jan. 31, 2001, near Japan.

Sincerely,

Robert Patlovany