DUBUQUE, Iowa (AP) — Federal investigators say the loss of airplane control in bad weather likely caused a 2014 crash that killed a Dubuque physician who was running for the U.S. Senate.

The National Transportation Safety Board report says no mechanical problems with the plane were found to have caused the Oct. 13, 2014, accident in which 59-year-old Doug Butzier died.

He was returning to Dubuque from a campaign trip and flying his single-engine Piper Malibu on instruments because the bad weather prevented a visual approach to the Dubuque airport. Butzier missed on his initial approach and was circling for another attempt when his plane struck some trees.

The board report blamed the crash on "the pilot's loss of airplane control while attempting to fly a missed approach procedure in instrument meteorological conditions."

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