I have a question, Often I hear pilots saying the plane was built like a Brick Sh#@house. I understand the sentiment, but on what criteria are we basing this on? For ex, My airline flies alot of 727-100's built in the mid 60's thay never break!! and seem to be rugged, however we also fly DC-8's and they are said to have "No airframe time Limits" because Douglas had overbuilt them. The DC-8's are indeed built like tanks!! But what jets weren't? Is it just perceptions or are their hard facts to prove these claims? just a fun subject to talk about.