Approved for Release: 2013/06/25
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Secret NOFORN
Chapter 6
279
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[figure]
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invention of synthetic lubricants. Lockheed also had to search long and hard for a hydraulic fluid that would not vaporize at high speed but would still be usable at low altitudes. Finding a suitable hydraulic pump was just as difficult. Kelly Johnson finally modified a pump that was being developed for North American’s B-70 bomber project.²¹
Some of the greatest problems related to the high speeds and high temperatures at which the OXCART operated resulted from working with the material chosen for the airframe—titanium. After evaluating many materials, Johnson had chosen an alloy of titanium
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²¹ Johnson, “Development of Lockheed SR-71,” pp. 11-12.
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Secret
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Approved for Release: 2013/06/25