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Mobility Capabilities: DOD's Mobility Study Limitations and Newly Issued Strategic Guidance Raise Questions about Air Mobility Requirements

GAO-12-510T Published: Mar 07, 2012. Publicly Released: Mar 07, 2012.
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What GAO Found

The Mobility Capabilities and Requirements Study 2016 (MCRS-16) provided some useful information concerning air mobility systems—such as intratheater airlift, strategic airlift, and air refueling—but several weaknesses in the study raised questions about its ability to fully inform decision makers. In particular, the MCRS-16 did not provide decision makers with recommendations concerning shortfalls and excesses in air mobility systems. In evaluating capabilities, the MCRS-16 used three cases that it developed of potential conflicts or natural disasters and identified the required capabilities for air mobility systems. Based on data in the MCRS-16, GAO was able to discern possible shortfalls or potential capacity that could be considered excess or an operational reserve, even though the MCRS-16 was ambiguous regarding whether actual shortfalls or excess capabilities exist. It also did not identify the risk associated with potential shortfalls or excesses. Identifying the risk associated with specific mobility systems could help with decisions to allocate resources.

The Department of Defense (DOD) issued new strategic guidance in January 2012, which is intended to help guide decisions regarding the size and shape of the force. In the past, DOD has translated strategic guidance into specific planning scenarios, which it used in studies (such as the MCRS-16) to generate requirements that inform force structure decisions. Based on the new strategic guidance, the Air Force has proposed reducing its mobility air fleet by 130 aircraft, which would leave 593 mobility aircraft in the airlift fleet. According to Air Force officials, the proposals will enable the Air Force to deliver the airlift capabilities required to implement the new strategic guidance and remain within funding levels. However, the Air Force’s document that outlines its proposed aircraft retirements does not provide details of any analyses used to support the reductions. Given the new strategic guidance, it is unclear the extent to which the requirements developed from MCRS-16 are still relevant. In weighing the Air Force’s proposal, decision makers would benefit from a clear understanding from DOD of the basis for the proposed aircraft retirements and DOD’s ability to execute its new strategic guidance with its planned air mobility force structure.

Why GAO Did This Study

Over the past 30 years, the Department of Defense (DOD) has invested more than $140 billion in its airlift and tanker forces. In 2010, DOD published its Mobility Capabilities and Requirements Study 2016 (MCRS-16), which was intended to provide an understanding of the range of mobility capabilities needed for possible military operations. In January 2012, DOD issued new strategic guidance, Sustaining U.S. Global Leadership: Priorities for 21st Century Defense, affecting force structure decisions. This testimony addresses GAO’s previous findings on the MCRS-16 and air mobility issues to consider in light of DOD’s new strategic guidance.

GAO’s December 2010 report on the MCRS-16 (GAO-11-82R) is based on analysis of DOD’s executive summary and classified report, and interviews with DOD officials.


GAO previously recommended that DOD clearly identify shortfalls and excesses in the mobility force structure and the associated risks. DOD did not concur with the recommendations, stating that the MCRS-16 identified shortfalls and excesses and included a risk assessment. GAO disagreed, noting for example, that DOD’s MCRS-16 study did not explicitly identify excess aircraft and did not include mobility system risk assessments when potential shortfalls existed.

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AircraftStrategic airliftU.S. Air ForceForce structureMilitary operationsIntratheater airliftNational securityIn-flight refuelingMilitary forcesHomeland security