B-2 Bomber:

Review of the Air Force's Decision to Change Extremely High Frequency Satellite Communications Antennas

GAO-11-180R: Published: Dec 16, 2010. Publicly Released: Dec 16, 2010.

Additional Materials:


Michael J. Sullivan
(937) 258-7915


Office of Public Affairs
(202) 512-4800

The B-2 bomber is a low-observable, long-range strike aircraft capable of entering heavily defended areas to deliver both conventional and nuclear weapons. The B-2 currently uses an ultra high frequency (UHF) satellite communications system, but because of aging military satellites, the Air Force determined a new communications system was needed. As a result, the Air Force began an incremental acquisition approach for replacing the B-2's existing UHF satellite communications system with an extremely high frequency (EHF) communications capability. The first increment, which is expected to begin production in late fiscal year 2011, is designed to upgrade computer system speed and storage capacity. The second increment is expected to provide secure, survivable strategic communications connectivity, thus allowing B-2 pilots to receive emergency action messages during strategic operations--an EHF capability that U.S. Strategic Command has stated it needs by fiscal year 2016. The third increment is intended to enable the EHF system to connect with the Global Information Grid. The focus of our review was the second increment, which is scheduled to enter the engineering and manufacturing development (EMD) phase in early fiscal year 20131 and has an estimated total acquisition cost of $1.9 billion. In March 2008, the Air Force started a technology development and concept refinement phase for the second increment of the EHF system. In summer 2008, Air Force officials raised concerns during systems engineering activities about integration plans for a new EHF antenna subsystem, particularly as they related to the planned antenna location. As a result of these concerns, the Air Force decided to change the location of the antenna for the EHF system, and also changed the type of antenna it planned to use from a mechanically steered array to an active electronically scanned array (AESA). Because of concern over the change in antenna, the Senate Armed Services Committee directed us to review the decision process used by the Air Force to make a change in the antenna approach.4 This Senate direction was in addition to a request from the House of Representative's Armed Services Committee, Air and Land Forces Subcommittee for us to (1) review the decision-making process used to support the antenna changes, and (2) determine the extent to which the program is employing a knowledge-based acquisition approach to identify and resolve technical gaps prior to the start of EMD. On August 17, 2010, we briefed our findings to congressional staff.

The Air Force's decision to change the antenna location to lower risks appears reasonable. However, the Air Force's decision process used to change antenna type was not supported by comprehensive, detailed analyses of cost, schedule, and technical risks for alternative antenna options. Without such analyses, it is difficult to determine whether the program is pursuing the most cost-effective and lowest risk antenna solution. An Air Force Aeronautical Systems Center (ASC) Acquisition Center of Excellence expert panel that examined the antenna selection process found the decision to exclusively pursue an AESA antenna may have precluded lower risk, more mature, and more affordable options. Finally, while the program's acquisition strategy incorporates several knowledge-based practices, there are additional options, particularly the pursuit of more robust competitive prototyping and maturing technologies to higher readiness levels, that could help reduce risk and improve the program's chances of a successful outcome.

Dec 5, 2016

Oct 5, 2016

May 4, 2016

Apr 27, 2016

Feb 3, 2016

Sep 18, 2015

Jun 2, 2015

May 21, 2015

Looking for more? Browse all our products here