The second-largest military contractor would be the McDonnell Douglas Corporation, with revenues of $14.4 billion last year.
As the nation's second-largest military contractor, Boeing is dependent on buying decisions from the committee.
Mr. McSweeny's departure continues a period of upheaval at General Dynamics, the nation's second-largest military contractor.
Boeing is the world's largest aerospace company and the country's single largest exporter but only its second-largest military contractor after the Lockheed Martin Corporation.
With the consolidation, General Dynamics, the nation's second-largest military contractor, has eight divisions and six subsidiaries.
Over the next four years, the nation's second-largest military contractor will let 27,000 workers go.
G.E., the nation's second-largest military contractor, said it was investigating the contract problems.
The company, the nation's second-largest military contractor, said the decision made sense in light of the heightened competition among contractors as the Pentagon cuts costs.
Boeing, the second-largest contractor for the Defense Department, has operated under a heightened level of security since the terrorist attacks.
Lockheed, the nation's second-largest military contractor, must respond today to the Government's threat to block the deal on antitrust grounds or face court action.