Three Civil Air Patrol planes from California launched Sunday morning to help find the plane that had two people aboard when it went missing.
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The Socata TB-20 left the Truckee-Tahoe Airport near the Nevada border April 17.
It was expected to land about 180 miles away at the Petaluma Municipal Airport north of San Francisco.
Family members reported the four-seat plane missing and a search was started by the Civil Air Patrol, the all-volunteer civilian auxiliary of the U.S. Air Force.
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CAP, along with the California Highway Patrol and the California National Guard, continue to assist the Sierra and Nevada County sheriffs' offices in the search.
The three CAP planes, flown by aircrews from California, are conducting visual and photographic searches of an area in the Sierra Nevada about 18 miles northwest of Truckee.
Multiple agencies are participating in the ground search.
Weather hampered aerial operations during the week, but air and ground searches resumed Friday.
ABC7 News contributed to this story.