Mitigating Mid-airs

Balancing Biology with Technology To Help You “See and Avoid”

Source: FAA Safety Briefing
By: Tom Hoffmann

We all know the strengths and weaknesses of our aircraft, including the inevitability that what might be a clear advantage for one can be a complete detriment for another. Nowhere is this distinction more evident than in maintaining visual separation from other aircraft, aka, see-and-avoid. The near polar opposite blind spots found on many high and low wing GA aircraft have all too often been a leading cause in mid-air or near mid-air collisions. Although Cessna and Piper owners may vehemently argue why each of their respective models offers superior collision avoidance, it really boils down to pilot know-how more than having any kind of built-in design advantage.

Pilots actually have several techniques and tools at their disposal during flight to avoid a mid-air, such as communication, clearing procedures, and visual scanning techniques. But any pilot knows that these techniques all have limitations and that even the most skilled and diligent pilot is still susceptible to an unseen aircraft encounter. That’s where technology can help, particularly Automatic Dependent Surveillance-Broadcast (ADS-B) technology. ADS-B has greatly improved situational awareness for GA operators. With ADS-B, each aircraft broadcasts its own GPS position along with other information including heading, ground track, groundspeed, and altitude (ADS-B Out). With its counterpart system installed (ADS-B In), avionics have the ability to receive and process those data signals and present a visual display of that traffic to the pilot.

Realizing the great potential technology like ADS-B has to help enhance the visual depiction of traffic, the National Transportation Safety Board (NTSB) issued a Safety Alert titled “Prevent Midair Collisions: Don’t Depend on Vision Alone,” available at https://www.atc-network.com/atc-news/national-transportation-safety-board/ntsb-issues-safety-alert-to-pilots-on-midair-collision-prevention. The Alert highlights some of the recent mid-air collision accidents the agency has investigated and which it believes that cockpit traffic dis-play technology, like ADS-B (In), could have helped to prevent. The Alert also advises pilots to become familiar with any new equipment they use for collision avoidance and fully understand its limitations. “High-density traffic around airports can make interpreting a traffic display challenging due to display clutter, false traffic alerts, and system limitations,” the report states.

A personal connection to a mid-air collision over Warrenton, Virginia in 2012 was the motivation for Aviation Adventures Flight School owner Bob Hepp to equip nearly all of his fleet of 45 aircraft with both ADS-B Out and In. The accident, which involved one of Hepp’s chief instructors, made him realize just how inadequate see-and-avoid by itself was, as well as the need to get more traffic information into the cockpit. “If anybody’s operating an aircraft in a high-traffic area, I really can’t understand why they would not want to get ADS-B In when they’re just meeting the mandate of ADS-B Out.”

While ADS-B technology can be a game-changer when it comes to improving situational awareness, pilots also need to be wary of spending too much time on displays rather than their outside environment. FAA Advisory Circular (AC) 90-48D warns pilots about maintaining this sort of vigilance. The AC states that traffic information equipment does not relieve a pilot of the responsibility to see and avoid other aircraft, and that managing distractions caused by the use of technology in the cockpit is critical to the safety of the flight.

In addition, the NTSB Safety Alert also reminds us that “unless your system is also capable of providing resolution advisories, visual acquisition of and separation from traffic is your primary means of collision avoidance (when weather conditions allow).” So to make sure your technology is complemented by the proper biology, please review AC 90-48D. It has plenty of tips on how to flex those Mark Ones and keep your visual acuity in tiptop shape.

Learn More

How to Avoid a Mid-Air Collision, FAA Safety Team publication - https://www.faasafety.gov/gslac/alc/libview_normal.aspx?id=6851

FAA Video: ADS-B and General Aviation - https://youtu.be/saEdkbq0ZT8