1. But approaching or reaching supersonic speeds presents a new set of aerodynamic problems that raise risks in areas that are unknown. 2. For the Department of Defense, flapping offers a way around aerodynamic problems that make it hard to miniaturize fixed-wing planes. 3. The contract had been held up pending agreement on a design fix to remedy aerodynamic problems. 4. Then the Navy held up release of the funds pending resolution of what officials described as an aerodynamic problem called wing drop. |
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