Congratulations to the Boeing Co. board for holding its top executive to the standards set in the company’s code of conduct.

Amid the many recent scandals involving CEOs of large U.S. corporations, it’s refreshing to see the Boeing Co. stand by its own code of business conduct even when enforcing that code leads to the departure of the company’s top executive.

Harry Stonecipher, president and CEO of Boeing, resigned at the request of the company’s board Monday after it came to light that the married 68-year-old Stonecipher had had a relationship with a female Boeing executive.

Boeing’s board chairman said that having an affair is not, in itself, a violation of the company’s code of conduct, but additional circumstances surrounding the relationship led to the board’s determination that Stonecipher had violated the code and his actions “would impair his ability to lead the company.”

It was a blow to the company. Stonecipher was the second Boeing CEO to resign in scandal within the last 15 months. His predecessor, Phil Condit, left the company as the result of a defense contracting scandal that sent an Air Force procurement officer and Boeing’s chief financial officer to jail.

In that context, it’s understandable that Boeing board members are of a mind to have zero tolerance of inappropriate behavior by its top executives.

It’s ironic that Stonecipher reportedly had been an outspoken advocate of adhering to ethical conduct and defending Boeing’s code. It too often seems that executives at the top of a company consider themselves to be exempt from many of the rules that apply to other employees. It’s a credit to Boeing’s board that it decided that the company’s ethical standards should apply to all its employees, starting at the top.

The company has withheld the name of the female executive who was involved and isn’t going out of its way to sully Stonecipher’s reputation, but the board left no question about the primary reason for his departure.

The American public — not to mention company stockholders — should welcome Boeing’s action and hope it sets an example that will make other corporate boards more willing to take a hard line in requiring ethical and appropriate behavior from their top executives.