Narrative:

Two days after the flight; the glider instructor was told on the phone by the tow pilot (the tow pilot was e-mailed by the instructor to 'please call') that; due to a power loss; he released the glider during the initial climb-out left-turn. From the instructor's portable flight recorder the release was at 70 feet AGL and 328 feet beyond the runway threshold. Immediately after the release; the instructor continued the left-turn back toward the airport. To avoid trees and a fence; the instructor landed the glider very hard in the field directly across the street from the runway threshold. From the flight recorder; the glider was in the air a total 54 seconds; 13 seconds were after the release. Thus; the pilot had no time or altitude to make a normal touchdown. The left-wing tip struck the ground just as the pilot initiated a right turn to level the wings. This caused a violent ground loop that ended with the impact of the main wheel (above which the instructor was sitting) at 42 mph with the ground. The hard landing caused a burst fracture of the instructor's T12 vertebra and minor damage to the glider. The student pilot was uninjured. The tow plane landed safely after the release. During the phone conversation; the instructor asked the tow pilot the following questions:1) what happened to the tug? Loss of power; terrible vibration; about to blow a cylinder.2) why did it happen? Don't know; water in fuel? After I landed; our a&P and I checked all and all appeared normal.3) what must be done so a similar incident never happens again? Don't know; pre-launch test flight the tug which I normally do not do.the glider instructor thinks the tow plane must be inspected by an independent (non-club) and qualified a&P to reproduce the 'power-failure' and recommend necessary preflight measures to prevent the 'failure'. If the 'failure' cannot be reproduced; then make the tow-plane more powerful so an additional 100 ft could be gained upon initial climb allowing a normal return to the field by the glider if the 'failure' occurred.

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Original NASA ASRS Text

Title: Glider instructor reported his aircraft was released early due to the tow plane losing power with a subsequent hard landing; back injury to the instructor; and minor damage to the glider.

Narrative: Two days after the flight; the glider instructor was told on the phone by the tow pilot (the tow pilot was e-mailed by the instructor to 'please call') that; due to a power loss; he released the glider during the initial climb-out left-turn. From the instructor's portable flight recorder the release was at 70 feet AGL and 328 feet beyond the runway threshold. Immediately after the release; the instructor continued the left-turn back toward the airport. To avoid trees and a fence; the instructor landed the glider very hard in the field directly across the street from the runway threshold. From the flight recorder; the glider was in the air a total 54 seconds; 13 seconds were after the release. Thus; the pilot had no time or altitude to make a normal touchdown. The left-wing tip struck the ground just as the pilot initiated a right turn to level the wings. This caused a violent ground loop that ended with the impact of the main wheel (above which the instructor was sitting) at 42 mph with the ground. The hard landing caused a burst fracture of the instructor's T12 vertebra and minor damage to the glider. The student pilot was uninjured. The tow plane landed safely after the release. During the phone conversation; the instructor asked the tow pilot the following questions:1) What happened to the tug? Loss of power; terrible vibration; about to blow a cylinder.2) Why did it happen? Don't know; water in fuel? After I landed; our A&P and I checked all and all appeared normal.3) What must be done so a similar incident never happens again? Don't know; pre-launch test flight the tug which I normally do not do.The glider instructor thinks the tow plane must be inspected by an independent (non-club) and qualified A&P to reproduce the 'power-failure' and recommend necessary preflight measures to prevent the 'failure'. If the 'failure' cannot be reproduced; then make the tow-plane more powerful so an additional 100 ft could be gained upon initial climb allowing a normal return to the field by the glider if the 'failure' occurred.

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.