@feld @saxnot @nixCraft
The requirement wasn’t ‘redesigning the fuselage’ it was to design an entirely new aircraft.
The present series of 737 is a frankenplane. The powerplant evolution has brought issues at every iteration due to short undercarriage legs designed to accommodate ground clearance for 1960s era low bypass turbojets.
Its avionics evolution has brought issues too: fundamentally a replicated/L-R side config where pilots expected to read the displays & ‘vote’ whether L or R presented the correct information (FBW & other common safety critical systems are triplex).
@winterayars
No doubt the 737 was a great aircraft in the 60s. Operators continue to fly -200s, one has even retrofitted electronic displays into the flight deck.
I was a big fan of the 757 and have often thought it should’ve been the mid-market aircraft. But I’ll accept the 757 was more equivalent in capacity to the A321 so the market makers at Boeing likely saw the 757 as too big while Airbus was selling A318s and A319s to compete better in 737 Classic replacement opportunities.
An evolved FBW 757 using 777/787 derived avionics would have been a great aircraft.
I’d rate the 777 as the last great aircraft to be designed & built by Boeing.
@guardeddon I don't know about "frankenplane", I'd describe it more like a design that has been stretched, bloated, and warped far beyond its original design goals. Maybe that's the same thing, though. Doing a totally new plane is expensive, taking an existing plane and changing it is cheap--and Boeing can talk the FAA into letting them only certify the new parts (and not the plane as a whole) so it's really cheap!
The original 737 series (737-100 and 200) was lauded for being an amazing plane for the 1960s. Nice to ride in, nice to fly, nice to maintain. However, you can look at the design and tell it bears almost no similarities to the monsters that now bear its name: http://www.b737.org.uk/737original.htm#737-100
Despite all the changes from that original design, they're still (as far as i know) flying under a modification of the original certification for the design from 1967. Because of the work of Boeing's engineers, the FAA, and airlines the plane has remained quite successful but i don't think Boeing is going to be able to push this thing further. It's clearly hitting its limits, at least without major design investment.