Interesting hit on N474NA - pinging Mode S AA0DB8 (1850-1906 Pacific Time, 20 Feb, 36-37 Thousand Feet) - NASA Stratospheric Observatory For Infrared Astronomy (SOFIA) - I understand it operates out of Edwards AFB in California - No position info but I picked up the Mode S here in Reno NV - I remember seeing a program on TV a while back about all the modifications that were made on the 747 - neat to see it on the Radarbox - I now have it in my alerts.