SACRAMENTO (CBS Sacramento/AP) — The California Highway Patrol’s fleet of airplanes and helicopters may be getting old, but state lawmakers should not fund the purchase of replacements until the state police force justifies why it needs 26 new aircraft, according to the independent Legislative Analyst’s Office.

The recommendation came Thursday, when the office released its review of Gov. Jerry Brown’s 2014-15 transportation budget proposal.

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Currently, 19 of the CHP’s 30 aircraft have flown more than 10,000 hours — when maintenance becomes costly and some aircraft risk being unsafe, according to Brown’s budget spokesman, HD Palmer. He called the replacement plan a “safety-driven request.”

The CHP has said it wants to downsize to 26 aircraft, and lawmakers approved $17 million in the current budget to start the process by buying three helicopters and one plane. None has yet been acquired.

In his proposal for the budget year that starts July 1, Brown requested $16 million to replace two planes and two helicopters.

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The analyst’s office wrote that the CHP has not justified why 26 would be the right number, “particularly given limited resources and the high cost to purchase, operate, and maintain the aircraft.”

The office also suggested that the CHP could ask local law enforcement agencies which rely on CHP aircraft, sometimes because their own tight budgets meant a cut in their own fleets, to reimburse CHP for some costs.

The aircraft are used for a range of missions, including patrolling electrical and water infrastructure, emergency response, and enforcement of speed limits. Each aircraft costs about $2 million annually to operate and maintain.

The CHP deferred comment to Palmer, though a spokesman said the agency’s helicopters are used in harsh environments such as deserts, where sand can cause problems, as well as in national parks where the CHP conducts search and rescues under an agreement with the federal government.

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