Citing 60 near mid-air collisions between gliders and airplanes over the past 20 years " nine of them in northern Nevada, the National Transportation Safety Board recommended Tuesday all gliders be required to operate with transponders that alert their presence to air traffic controllers and other aircraft.
Gliders and other aircraft without engine-driven electrical systems currently are exempt from a rule the Federal Aviation Administration imposed in 1988 requiring transponders for all other aircraft that operate near primary airports and in airspace above 10,000 feet.
NTSB Chairman Mark Rosenker recommended in a March 31 letter to the NTSB that the glider exemption be eliminated based in part on an NTSB investigation into an actual collision between a glider and a private jet about 40 miles southeast of Reno in August 2006.
In that case, the glider pilot " who parachuted to safety " had a transponder on his aircraft but had turned it off to conserve battery power. The Hawker 800XP airplane he collided with suffered significant damage but was able to land safely at Reno-Tahoe International Airport.
"As evidenced by this accident, aircraft that are not using or not equipped with transponders and are operating in areas transited by air carrier traffic represent a collision hazard," Rosenker wrote in the letter first made public on Tuesday.
"This hazard has persisted more than 20 years since the Safety Board initially expressed concern," he said.
Of the 60 near mid-air collisions from 1988 to 2007, nine occurred in the vicinity of Reno. That's due primarily to the large number of gliders that fly along the Sierra's eastern front where thermal air flows create what enthusiasts describe as "world class" gliding conditions.
The other most frequent sites of near misses were Chicago and Washington D.C. with four each. Colorado Springs, Colo., had three.
More than 10 years before the latest incident, the FAA's Reno Flight Standards District Office had warned FAA investigators that gliders are invisible to radar because they do not have a transponder.
'In addition, due to the design of the gliders, they are very difficult to see unless the air carrier is very close to them, which may be too late to avoid the glider," the office manager wrote in a memo April 11, 1997.
In the latest incident, both pilots reported they saw each other for only 1 second or less before impact.
The 1997 memo said the FAA flight office in Reno "has suggested that gliders carry transponders and/or communicate with" the control tower at Reno-Tahoe International Airport but "the glider community does not want to adopt the FAA's suggestions."
In the new recommendation, the NTSB praised the glider community and others for taking "steps in the right direction" to educate pilots about dangers and take safety precautions.
"However, because the collision threats observed by Reno FSDO personnel 10 years ago persist today, the Safety Board concludes that the safety measures implemented by the FAA to notify air carriers and other (Reno)-area traffic of glider activity are insufficient to prevent collisions," Rosenker wrote.
NTSB "concludes that transponders are critical to alerting pilots and controllers to the presence of nearby traffic, so that collisions can be avoided and that gliders should not be exempt from the transponder requirements."
The FAA has 90 days to respond to NTSB's recommendations, FAA spokesman Ian Gregor said.
"We take NTSB recommendations very seriously," he said from Los Angeles.
Leaders of the Soaring Society of America based in Hobbs, N.M., and other gliding enthusiasts oppose NTSB's move. They advocate alternatives including increasing awareness of high traffic areas to pilots and implementing new technologies already in use in some parts of Europe that provide low-cost, real-time information to pilots.
"The SSA is disappointed that the NTSB took a very narrow view of the causal factors and did not address some of the changes we specifically recommended," said Stephen Northcraft, chairman of the group's government liaison committee.
Leo Montejo, president of the Minden Soaring Club south of Reno, advocates the use of transponders but said they should be allowed to be turned off when flying over remote areas away from normal air traffic patterns.
Most modern gliders have solar-powered batteries that help conserve power but even those don't help on longer flights that can stretch 8 hours cover 500 miles, he said.
"Having a transponder on all the time becomes a real problem with energy conservation on your glider," he said.
Fred La Sor, an owner of Soaring NV in Minden who has been flying gliders for 35 years and helped develop new safety plans for the Reno area after the last incident, said it costs $2,200 to $3,000 to put transponders on most gliders. He also said most collisions or near-misses involve two gliders, not a glider and a jet, something he said would not be affected by transponders.
La Sor said some gliders in places like California and Ohio might be able to operate below 10,000 feet without transponders. But he said it would be difficult to do so along the Sierra front where "soaring conditions are absolutely the best in the world " world class."
"I moved here from Ohio for this," he said. "They are very special conditions and we want to preserve them. To just cross off the area and say you can't fly gliders here, it would be criminal."
