Sunday, August 09, 2009

Hudson River Mid-Air Collision

Aircraft Blind SpotsBecause I am a seasoned pilot of 20 years and a New Yorker, a number of people have asked my opinion about the Hudson River Mid-Air Collision last weekend. I have spent some time formulating an explanation about what may have happened on that beautiful Summer day over the Hudson. The accident investigators from the NTSB will produce a comprehensive and fully supported explanation within 6 to 12 months, outlining their findings. The post that follows details my initial impressions of what most likely caused the accident.

I was in New York City over the weekend and marveled as a Cessna 182 flew by me on the Hudson River at approximately 800 feet. The plane was flying up what is commonly known as the Hudson River Corridor, a slice of uncontrolled airspace underneath the highly controlled New York Class B Airspace. The Hudson River Corridor provides a welcome gateway to transit through New York Airspace without having to get an often unattainable Class B Clearance from New York TRACON.

Hudson Corridor Mid-Air Collision

Ironically, a few hours after seeing the beautiful Cessna 182 pass overhead, I heard about the mid-air collision of a Piper Saratoga and an AS 350 Tourist Helicopter.

I have flown the Corridor countless times and have been amazed at the volume of traffic and the orderliness by which the various aircraft navigate the airspace and "see and avoid" each other without any tacit government intervention.

Hypothesis - Blind Spot

Aircraft, airplanes and helicopters alike have blind spots just like automobiles. Based upon the description of the accident I surmise that the Piper Saratoga was above and overtaking the AS350 and was blind to the helicopter. The helicopter was below and ahead of the Saratoga and could not see the airplane because it was outside of the purview of the pilot's visual scan.
Neither aircraft, nor pilots have "eyes in the back of their heads," but situational awareness can be improved with advanced technology in the cockpit.
The Aircraft Owners and Pilots Association produced a comprehensive report on Collision Avoidance, that provides a wealth of information about collision avoidance causes, factors, and means of mitigation. This is a great resource if you want to learn more about how mid-air collisions can can avoided.

Collision Avoidance Technology

When comparing options for safety, I think it is important to highlight the merits of modern collision avoidance technology over the more myopic suggestions to shut down the Hudson River Corridor coming from Capital Hill. Such knee jerk reactions from politicians with merely generalist knowledge of aviation safety, and a greedy eye on reelection, will result in a system whereby the pendulum will shift too far right with a unnecessary loss of valuable flexibility.

Collision avoidance technology is similar to automobile back up sensor technology that provides an audible and/or visual cue when a car detects an obstacle at the rear of a car when backing up. Collision avoidance systems provide a visual or data reference to other aircrafts in the area and substantially enhance a pilot's ability to "see and avoid."

I fly with a PCAS XRX from Zaon and have been alerted to traffic on numerous occasions long before I was able to see it with my own eyes. I personally will not fly without collision avoidance technology in the cockpit.

There are a variety of collision avoidance technologies ranging from $500 to over $100,000. When flying in controlled airspace, I often hear the controllers calling out traffic to airplanes and the pilot responding with "I see him on TCAS (Traffic Collision Avoidance System), but no joy [I do not see the traffic yet]."

Much like abstinence is the safest way to avoiding pregnancy, it is not the only option nor even considered to be realistic by most people. Such is the case with collision avoidance whereby closing down the corridor will guarantee collision avoidance, it is neither a reasonable nor viable solution to the ongoing effort by the Air Safety Foundation and all members of the flying community to completely eliminate mid-air collisions. Accidents happen and unfortunately they will continue to do so, collision avoidance technology is one of the best means of accident mitigation.

If you want to learn more about collision avoidance, check out the following articles:

We will never know definitively, but there is a good chance that a good collision avoidance system may have helped to avoid this tragedy, closing the corridor will not.


  1. Excellent article Jonathan - people want answers when something like this happens. I appreciate your insight getting to the cause rather than the knee jerk reaction of more regulation.

  2. Jonathan,

    Gov't is not the answer to our problems, as tragic as the lesson is; it is in fact a lesson to all pilots to have the right equipment, the right training and personal ownership for their lives and their passengers

  3. Changes to the Hudson River Cooridor in response to the Hudson River Mid-Air.