Glider in Midair Didn’t Turn on Transponder

The Schleicher sailplane that collided with a NetJets Hawker 800XP at about 16,000 feet near Smith, Nev., on August 28 was equipped with a transponder but it was not turned on. Transponder activation is not required for glider operations below 18,000 feet msl and outside controlled airspace. The glider pilot said he did not turn on the transponder because he intended to remain only in the local glider area and because he wanted to preserve his battery power for radio use. Since the glider’s transponder was not operating, the Hawker’s TCAS would have received no threat alert and the glider would probably have been invisible to ATC radar (unless it happened to paint the aircraft itself as a primary target).