Two gliders in thermal activity have near midair collision.

Attributes
ACN	157248
Time
Date	199009
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : tx23
State Reference	TX
Altitude	msl bound lower : 6000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Sail Plane
Flight Phase	cruise other cruise other other
Flight Plan	None
Aircraft 2
Operator	general aviation : personal
Make Model Name	Sail Plane
Flight Phase	cruise other cruise other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 40 flight time total : 190 flight time type : 40
ASRS Report	157248
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Events
Anomaly	conflict : nmac other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : regained aircraft control flight crew : took evasive action
Consequence	other Other
Miss Distance	horizontal : 50 vertical : 0
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Pilot Deviation

Narrative:

Two high performance gliders thermaling (circling in lift) at the same altitude. I left the thermal for approximately 20 seconds losing sight of the other glider. Unknown to me he followed to my right but lost sight of me (evidently). I turned back to the right to return to the thermal and ended up with a face full of his glider. He did not see me until I turned. A contributing factor was that we both elected to dive to evade. We went through a couple of parallel pitch oscillations. I finally made full control input left and down and the incident was over with no contact. Total time involved was less than 10 seconds from the time I saw him until it was over.

Original NASA ASRS Text

Title: TWO GLIDERS IN THERMAL ACTIVITY HAVE NMAC.

Narrative: TWO HIGH PERFORMANCE GLIDERS THERMALING (CIRCLING IN LIFT) AT THE SAME ALT. I LEFT THE THERMAL FOR APPROX 20 SECS LOSING SIGHT OF THE OTHER GLIDER. UNKNOWN TO ME HE FOLLOWED TO MY R BUT LOST SIGHT OF ME (EVIDENTLY). I TURNED BACK TO THE R TO RETURN TO THE THERMAL AND ENDED UP WITH A FACE FULL OF HIS GLIDER. HE DID NOT SEE ME UNTIL I TURNED. A CONTRIBUTING FACTOR WAS THAT WE BOTH ELECTED TO DIVE TO EVADE. WE WENT THROUGH A COUPLE OF PARALLEL PITCH OSCILLATIONS. I FINALLY MADE FULL CTL INPUT L AND DOWN AND THE INCIDENT WAS OVER WITH NO CONTACT. TOTAL TIME INVOLVED WAS LESS THAN 10 SECS FROM THE TIME I SAW HIM UNTIL IT WAS OVER.

Data retrieved from NASA's ASRS site as of July 2007 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.