Narrative:

The event occurred during an early morning flight from the airport. It was during a planned hot air balloon rally. Conditions were good and favorable for flight. Situation occurred during initial approach to land. There were significant changes in the terrain upon approach to land; road surface; open field; water; and then trees. During approach to land; the two balloons moved toward each other and were in close proximity. There was incidental contact of the balloon fabric envelope to balloon fabric envelope. There was no injury or damage to persons or property or aircraft.evasive action was taken by maintaining altitude and steerage until practical for a separation of space; at which time the balloon was piloted to altitude and an alternate landing site was identified and a gentle landing was executed.it is believed that the action of the balloons was caused by advection creating a horizontal movement of air; resultant of the changes of ground surface conditions (pavement; open field; water; tree canopy).to prevent recurrence additional education in changing atmospheric conditions; and study of the effects of terrain on air movement should be exercised. It is also recommended that practicing contour flight over open terrain be executed as often as practical.

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Original NASA ASRS Text

Title: Two Hot Air Balloon fabric envelopes made contact during their approach to land because of significant terrain changes including the mix of road surfaces; open field; water; and trees.

Narrative: The event occurred during an early morning flight from the airport. It was during a planned Hot Air Balloon Rally. Conditions were good and favorable for flight. Situation occurred during initial approach to land. There were significant changes in the terrain upon approach to land; road surface; open field; water; and then trees. During approach to land; the two balloons moved toward each other and were in close proximity. There was incidental contact of the balloon fabric envelope to balloon fabric envelope. There was NO injury or damage to persons or property or aircraft.Evasive action was taken by maintaining altitude and steerage until practical for a separation of space; at which time the balloon was piloted to altitude and an alternate landing site was identified and a gentle landing was executed.It is believed that the action of the balloons was caused by advection creating a horizontal movement of air; resultant of the changes of ground surface conditions (pavement; open field; water; tree canopy).To prevent recurrence additional education in changing atmospheric conditions; and study of the effects of terrain on air movement should be exercised. It is also recommended that practicing contour flight over open terrain be executed as often as practical.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.