Mid-air collisions by gliders
Even though this article was published in 1995, the theme is still current.
Extract from flight accident information of the Flight Accident
Investigation Section of the LBA, August, 1995:
During the end of the 70’s and the beginning of the 80’s, the number of mid-airs by gliders grew to an intolerable number (15 per year). This theme was taken up by the DAeC and the Flight Accident Investigation Section of the LBA. During this year, 1995, there were 7 mid-airs already in normal thermal flying near airports, in contests and by hanggliders. Two glider instructors were killed. The others with more luck, were able to land safely but with severely damaged gliders.
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Has the feeling of being endangered by other gliders diminished?
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Has attention to possible danger been reduced by today’s many new instruments?
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Has the acceptance of risk become higher?
The gliding association rules recommend:
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The direction and manner of flying must be agreed upon by pilots flying in the same thermal region in order to decrease the chance of mid-airs. Coordination is more important than out-climbing each other.
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The first one to enter a thermal determines the direction of circling. All pilots entering after that must follow suit. Enter the formation in the thermal from the side.
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If the altitude difference between two gliders in a thermal is very small then they should fly the same circular path to prevent cutting each other off. Everyone should circle in the same direction even if there is a large altitude difference. This prevents confusing other pilots entering the thermal.
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Always fly such that you can see and be seen. Choose your own position so that eye contact with the others can be maintained. Give special consideration to student and inexperienced pilots.
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The number and position of gliders flying with you should always be kept in mind.
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Before all changes of direction check for traffic left, right, above and below.
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While in a group of circling gliders, pulling up is not allowed.
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Sudden, abrupt flight maneuvers in a group should be avoided. Your own maneuvers must be remain those that others in the group could expect.
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Climbing past someone else in a thermal must be done with a good safety margin.
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The danger of a mid-air should not be underestimated even in a small group. When meeting up on a cross country flight, stay on the air-to-air frequency. It is usual to have a safety frequency in a contest.
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Anything which interferes with visibility, such as reflections of the map in the canopy or wide brimmed hats, should be avoided.
Conclusion:
Remain alert and keep your eyes open.
If it gets crowded, fly defensively.
In questionable circumstances, it’s better to risk a lost of lift than your life!
translated by David Noyes, Ohio 