Why is it that some airliner prototypes are scrapped and some enter service? The first DC-10 is now sitting in Arizona after 20+ years of faithful service with American Airlines after being handed over in the early to mid 1970s, and is waiting to be converted to an MD-10 for FedEx. However, the first L-1011 was scrapped in Oklahoma in the 1980s after only 8000 flight hours. Why? Other examples include the first MD-90, recently scrapped, that made its first flight in April of 1993, while at the same time the first Boeing 777 will be delivered to JAL soon, after making its first flight in 1994 (I believe, maybe 1995?). The first MD-11 was converted to a freighter and now flies w/ FedEx. The first DC-8, an ex-Aeromexico example (XA-DOE) rests in Marana after many years of service. Why are some planes scrapped and others in service?