Brian Robertson, chief executive of Seal Beach-based Amonix Inc., died in a plane crash yesterday.

He was 38.

Robertson, a Huntington Beach resident, was piloting a 1980 Cessna, which crashed in a cornfield near York Airport in Pennsylvania, according to Northern York County Regional Police.

Amonix is a private company that manufactures solar power systems for commercial use in the U.S. and internationally.

Robertson became Amonix’s chief executive in 2009 when the company acquired Sunworks Solar LLC, a solar manufacturing plant developer that Robertson cofounded in 2008.

Robertson previously was president of Belmont-based SunEdison LLC, which was acquired by St. Peters, Mo.-based MEMC Corp., a maker of solar wafers and other products.

Robertson was a graduate of Massachusetts Institute of Technology and earned a master’s degree from Harvard Business School.

He is survived by his wife and three children.