An inside look at maintaining NASA's Boeing 747SP

Lufthansa Technik in Hamburg has just completed a maintenance check on a uniquely modified Boeing 747 that provides a window on the solar system and beyond. Ian Harbison reports

Just three Boeing 747SPs remain in regular service, two of those serving with Pratt & Whitney Canada as flying engine testbeds. The third is the Stratospheric Observatory for Infrared Astronomy (SOFIA). Originally delivered to Pan American World Airways (Pan Am) in May 1977 as N536PA (c/n 21441), the widebody was christened Clipper Lindbergh by Anne Morrow Lindbergh, Charles Lindbergh’s widow, to commemorate the 50th anniversary of his solo flight from New York to Paris in 1927.

It was later acquired by United Airlines in February 1986 and spent nine years with the Chicago-based carrier as N145UA. Retired and stored in December 1995, it was acquired by NASA in 1997 and sent to L-3 Integrated Systems in Waco, Texas for a conversion programme that lasted from 1998 to 2007.

Its first sortie after modification was on April 26, 2007, after which it was flown to NASA’s Dryden Flight Research Center (now the Armstrong Flight Research Center) at Edwards Air Force Base, California for continued flight testing. Here it was rededicat…

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