Well it's a well know procedure that when a company is developing a plane, to look at other planes to save on R&D costs. For example, when Lockheed got the order for a medium maritime patrol aircraft, they looked at their L-18 Lodestar airliner and took it from there, creating the Hudson. But in some instances, it's just the nose, the forward portion of the fuselage which is enough and there are some surprises wth the planes I'm going to mention. First up, the plane that got somewhat of a reputation, even a band like the Bloodhound gang mentioned it as being "Guaranteed to go down" but all the same is still a dependable workhorse now that all the kinks have been ironed out: the McDonnell/Douglas DC-10. A KDC-10 Extender as operated by the Royal Netherlands air force. The DC-10 was Douglas' first wide body long range airliner, a rival for the Boeing 747, it has been used as an airliner, a freighter and a military air to air refueling station and transport plane. So when MDD got an order for a medium heavy transport plane they decided to cut development costs by using the nose and all of the flight systems of the DC-10, resulting in the YC-15. The YC-15 was an astonishing plane, it could take off from very short runways, the thrust reversers were so powerful that it could go backwards and it proved to be tough as nails. The USAF was impressed enough to order it into production and the subsequent developed version of that plane has become a mainstay of the USAF: The C-17 Globemaster. The C-17 still has the nose of the DC-10. Father and son and the family resemblance is all in the nose. To continue, here's another plane which got a real reputation for coming down, the graceful DeHavilland DH-106 Comet. We all know how the Comet was the first jet airliner to enter service but what's best known about the Comet is how it became known for a condition called metal fatigue. But what isn't that well known is that Comet, once the kinks were ironed out was kept into service well into the seventies. A diagram on how later versions of the comet differed from the version that crashed seeming all of the time. But it was across the channel that the French bought the licensing rights to the Comet, not the whole plane, just the nose. The Sud-Est Caravelle, used the entire forward fuselage of the Comet, which included all of the flight systems, the Caravelle is also important in it being the very first airliner to utilize the twin engines at the tail configuration, that planes like the DC-9 would be so successful at. Again the family resemblance is all in the nose here.