SACRAMENTO (CBSLA.com/AP) — California officials have reactivated the state’s 22 firefighting air tankers days after one of the aircraft crashed in Yosemite National Park, killing the pilot.

California Department of Forestry and Fire Protection spokeswoman Janet Upton said Friday the department lifted the safety stand-down for the twin-engine S-2T airplanes after federal investigators approved letting the planes fly.

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CAL FIRE officials had said the planes would remain grounded until the National Transportation Safety Board preliminarily determined the crash on Tuesday wasn’t related to mechanical problems that could affect other aircraft.

NTSB officials notified CAL FIRE that their investigation into the Tanker 81 accident found no structural failures or aging aircraft issues involved in the crash, according to CAL FIRE.

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The planes were grounded after pilot Geoffrey “Craig” Hunt was killed when his plane smashed into a steep canyon wall while dropping retardant on a fire near the park’s west entrance.

“This has been a difficult week for the Department,” said Chief Ken Pimlott, director of CAL FIRE. “Words can’t express my sorrow for the Hunt family, but I am incredibly thankful of the work our pilots, employees and fire service partners have done following this tragic accident.”

Officials say airbase personnel have returned to routine daily safety inspections and will be permitted to resume normal flight activities Friday.

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