The Viper's serial number on nose is 2276NC. However, it's call sign was Viper 450. I believe that the 3-digit numbers like 450 or 591 are like the nose numbers on US Navy aircraft. For example, an F-14A Tomcat could have a serial number like 160299 but, since it is a fighter, it will have nose number in either the 100s or 200s. The Squadron commander's plane usually would have 00 at the end (100, 200, et al). Other aircraft would have nose numbers according to their type. For instance, A-6 Intruder attack planes could all have 400 and 500 series number, regardless of their serial number (That isn't the correct set of nose numbers for A-6s though). In flight operations, the nose number would be used to refer to the plane, just like Apollo when he first landed on Galactica. Captain Kelly referred to him as Viper 450. The 2276NC was visible on the nose (in low-viz markings unlike the Mk II) when Apollo met Tyrol. -By the way, the Tomcat serial number was for the first Tomcat sold to Iran, it ironically never had a Navy nose number. -I'll update the main article when I get back from my finals this afternoon. -Talos 12:15, 13 December 2005 (EST)