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Aerospace SR-71 Question

  1. Apr 23, 2010 #1
    My question is referring to the first picture of the SR-71 on wikipedia.


    What are those dark streaks on the wings of the aircraft near the engine?
  2. jcsd
  3. Apr 24, 2010 #2
    That's jet fuel leaking out of the seams. The SR-71 was designed to "seal up" at full speed through thermal expansion at Mach 3+. It has no fuel tanks in those sections of the wings. The fuel is stored directly in the bulkhead to save weight.
  4. Apr 24, 2010 #3
    Keen observation!
  5. Apr 24, 2010 #4
    You sparked my interest. I know the fuel is rather thick. It turns out to be JP-7. But check out this Wikipedia quote: "SR-71 development began using a coal slurry powerplant,"! I never would have guessed that one.
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