In the aviation industry designs really do stand the test of time. A large number of airliners,props and helicopters were designed back in the 60's and 70's wit

In the aviation industry designs really do stand the test of time. A large number of airliners,props and helicopters were designed back in the 60's and 70's with only a few minor upgrades here and there. I can almost understand why the new jet is having a hard time replacing the previous one. I say almost because at a trillion dollars... Lol