Rockwell Collins is upgrading the low-frequency transmission system of the US. military's E-4B Advanced Airborne Command Post.

The work, expected to be completed by Sept. 30, 2016, was contracted by Boeing for an unspecified amount and will be conducted at Rockwell Collins' facility in Richardson, Texas.

"This selection continues our heritage of providing the U.S. military with strategic command-and-control systems," said Troy Brunk, vice president and general manager, Airborne Solutions for Rockwell Collins. "We're continuing our strong relationship with Boeing by providing reliable, survivable and endurable communications between the President (of the United States) and our nation's nuclear forces."

The E-4B Advanced Airborne Command Post is designed to be used by the National Command Authority as a survivable command post for control of U.S. forces in all levels of conflict, including nuclear war. It also supports the U.S. Federal Emergency Management Agency by providing communications following natural disasters