In article ,
"Ozman Trad" writes:
"Ken Duffey" wrote in message

descendant of the Boeing B-29 !!

it is my understanding all modern passenger airframes are based on the
design of the B29

The B-29 pioneered a lot of the construction techniques and materials
used in modern aircraft (Well, a950-1960s modern, anyway, B-29s didn't
make any use of composites, for example.) Thick-skin construction,
the first large pressurized aircraft, the first large airplane built
with the armamant and sensor systems integrated into teh airframe from
the beginning, that sort of stuff.

It was also pretty much the first "Systems-Oriented" airplane, where,
in order to fly it effectively, it _required_ an integrated crew.
Before the B-29, Flight Engineers were, for the most part, Airborne
Crew Chiefs, as much there for Damage Control as anything else. In
the B-29, the FE was an integral part of the crew, acting as the
Systems Manager for the powerplants, fuel, and environmental systems.

That being said, there was a big departure in structural techniques
when the first U.S. jetliners wre designed (Boeing 707 & DC-8).
Instead of using the stuctural techniques that had been common
practice up to that point, ("Safe Life", which menat that you could
pretty much guarantee that an airframe would hang together for a
certain amount of time) both Boeing and Douglas developed "Fail Safe"
structures, which meant that, as much as possible, ther were no single
load paths which would allow, say, something like a fatigue failure to
cause catastrophic damage. I suppose a good practical example of that
would he the Hawaiian 737 that lost most of the upper portion of the
forward cabin in-flight.




--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster