Every Flight Resolution: Look Out the Window

By Scott Spangler on December 26th, 2022

Here’s hoping you had a happy Christmas, and that Mother Nature’s preparatory frosty whiteout didn’t deprive you the company of traveling to family and friends. With them on their way home, and the Christmas clutter cleared away, contemplating resolutions might be on your to-do list of New Year’s preparations. If you’re a current and active pilot, might I recommend the recently published Advisory Circular 90-48E, Pilots’ Role in Collision Avoidance.

NTSB Safety Alert SA-058 said: “The ‘see-and-avoid’ concept has long been the foundation of midair collision prevention. However, the inherent limitations of this concept, including human limitations, environmental conditions, aircraft blind spots, and operational distractions, leave even the most diligent pilot vulnerable to the threat of a midair collision with an unseen aircraft.”

The accident that inspired this alert involved two air tour aircraft in Alaska, but the NTSB’s recommendion works for any aircraft that operates in “congested airspace,” like the airspace around an airport—ADS-B with a Traffic Advisory System that “would provide significant advance warning….” Even with such a system, once warned pilots still need to look away from the ADS-B screen and out the window to locate the traffic with the Mark 1 eyeball.

The benefit of ADS-B is that it gives pilots a relative bearing on which they should begin their search. Reviewing the circular’s “Human Limitations Affecting See-and-Avoid” can improve the quality of the visual investigation if pilots address such things as blind spots by moving their head or repositioning a high or low wing to see what’s on the other side of the obstruction.

Avionics aside, the circular reinforces the reality that the human eye is “the most advanced piece of flight equipment in any aircraft” because “the number one cause of midair collisions is the failure to adhere to see-and-avoid concept, efficient use of visual techniques, and knowledge of the eye’s limitations.” Ignoring these aspects of looking out the window are the foundation of visual complacency. As most pilots know, and sometimes learn when it’s too late, complacency kills.

Key to a successful see-and-avoid search are the six conditions on which detecting airborne objects depend:

  • Image size—portion of the visual field filled by the object.
  • Luminance—degree of brightness of the object.
  • Contrast—difference between object and background brightness, color, and shape.
  • Adaptation—degree to which the eyes adjust to surrounding illumination.
  • Motion—velocity of the object, the observer, or both.
  • Exposure time—length of the time the object is exposed to view.

(If you’re really interested in learning more, the Scott Air Force Base Midair Collision Avoidance Pamphlet is more than worth the time it takes to read its 27 pages, 7 of which are dedicated to Scott’s airspace.)

Regardless of a pilot’s visual acuity, whether one is 20/15 or 20/400 corrected to 20/40, every eye needs time to accommodate and refocus on an object once detected. The circular includes an Aircraft Identification and Reaction Time Chart that was, literally, an eye opener—12.5 seconds between seeing the objects and the aircraft reacting to the pilot inputs to avoid it.

Then it delves into the other visual challenges pilots should always be aware of. Among them are empty-field myopia, tunnel vision, and the blossom effect, where two aircraft on a collision course appear virtually motionless until they suddenly explode in size, too often when it’s too late to avoid the collision.

And avoiding collisions in 2023 seems a pretty good resolution for all of us, in the air and on the ground whether we’re in an aircraft or some terrestrial transporter heading off to some holiday celebration. So why not make time to click the AC’s link and refresh and expand your knowledge of the components of see-and-avoid. May you all have a happy and safe New Year! –Scott Spangler, Editor


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One Response to “Every Flight Resolution: Look Out the Window”

  1. Ken Says:

    Brilliant article, would love to see more like this. alerted see and avoid us the most effective way to avoid mid air collisions for most pilots, using a correct ALAP scan.

    Even during my military training they overwhelmed us with gadgets like TCAS, IPads, (and even traffic alerts from air battle controllers using a TPS77 Radar which just seemed ridiculous flying CT4Bs at 120KTS), but it was always drilled into us ALAP, 90% of the time should be spend looking out and scanning, especially before any manouvering

    I’ve written a few articles about lookout on my blog, but will definitely be referencing this article in future

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