A Chinese aviation executive has pleaded guilty to conspiring to hack and steal sensitive data from Boeing Co. and other U.S. defense contractors, the U.S. Justice Department said Wednesday.

The guilty plea by Su Bin, who was arrested in Canada in July 2014, comes during strained relations between the U.S. and China over cyberespionage. U.S. prosecutors have been bringing more criminal cases against what American officials allege is rampant Chinese industrial espionage of civilian and military products.

Mr. Su faces a maximum sentence of five years in prison and a fine, the Justice Department said.

According to the plea agreement, Mr. Su said he sought to gain access to Boeing Co. networks containing data on the plane-maker’s C-17 Globemaster III cargo aircraft, which was manufactured in Long Beach, Calif., until 2015.

The Justice Department also alleged that Mr. Su and two other co-conspirators were seeking data on the U.S.’s most advanced stealth jet fighters, the F-22 Raptor and F-35 Joint Strike Fighter.