The spare engines, to be provided through the U.S. Foreign Military Sales program, are worth an estimated $35 million, the U.S. Defense Security Cooperation Agency said in its notification to Congress this week.
"The proposed sale will contribute to the foreign policy and national security of the United States by helping to improve the security of a friendly country that has been, and continues to be, an important force for political stability and economic progress in the Middle East," the agency said, and would help "improve the U.A.E.'s readiness and capability to meet current and future strategic airlift requirements."
The agency said the uses its C-17s to provide humanitarian aid in the Middle East and Africa region and to support its troops in coalition operations.
The prime contractor would be Pratt and Whitney. The Emirates' procurement of the engines wouldn't require temporary assignment to the emirate of U.S. government or contractor representatives.