Collision Avoidance

This is a summary of the collision avoidance section of the FAA Airplane Flying Handbook and is being used as a reference for training materials.

  • See and Avoid is the concept for the flight rules in 14 CFR part 91 which states that “vigilance shall be maintained all all times” by the pilot regardless of whether flying under IFR (instrument) or VFR (visual).
  • Pilots need to always be watching their surroundings.
  • Most mid air & near mid air collisions happen in good visibility, good weather & during the day within 5 miles of an airport. This means that these are most likely due to pilots not paying attention and watching for other aircrafts.

With “See and Avoid”, you have to be aware of the limitations on the human eye and use proper scanning techniques to offset these limitations.

In short, as a pilot, you need to be aware of all traffic movement in your field of visions as well any area outside the aircraft to make sure nothing is going to hit you and that you are not going to hit anything. Pretty common sense type of stuff. Pay attention at all times.

Other factors to take into account are as airplane performance capabilities and speed and rate of climb/descent. These have an impact on how quickly you can detect and make the decision on which action to take.

The more you look outside and the more you scan your surroundings, the more likely and quickly you are to identify a potential collision threat.

Scanning

There are some techniques that can be used to increase the effectiveness of the scan time. Since the human eye seems to alway focus somewhere, the pilot should glance in different ares and regularly refocus.

Generally this is done by scanning the instrument panel but it’s important to also focus outside to scan for other objects and to be aware of any potential hazards in the sky.

It may take a few seconds for the eyes to refocus when switching between the instrument panel and outside, especially if there is a distant object.

Efficient scanning involves spreading your attention with all of the piloting tasks and can be affected by any of the following mental and physical conditions:

  • fatigue
  • boredom
  • illness
  • anxiety
  • preoccupation

Basically, scanning a series of short and regularly spaced eye movements across the sky can create a central visual field which will help to create a big picture.

Each pilot should develop and stick to a comfortable scanning pattern keeping in mind the following

  • each movement should not ┬ábe more than 10 degrees
  • each area should be observed for at least 1 second
  • horizontal eye movements seem to be preferred by most pilots