Boeing 707, 727 and 737 fuselage cross-sections.
Thread Starter
Boeing 707, 727 and 737 fuselage cross-sections.
For the 707, Boeing employed what looks like (head-on) an oval shape cross-section. The 727 used an apparently perfectly circular section. The 737 saw a reversion to the 707 style. Does anybody know why Boeing didn't stick to one design for its narrowbodies ?
Thankyou.
Thankyou.
It's a double bubble - top and bottom are cylinders of different radii with a floor to take up the difference in load - picture a round section pulled inward by the floor. It allows more width at the shoulder height of the passengers which allows more seats across the width. It probably requires a small weight increase over a circular section. For a large enough diameter it is less useful.
Thread Starter
Thankyou Mech, that's what I thought. I work extensively with 737s and have noticed the double bubble. It just seems strange that Boeing abandoned that particular design for the 727 and then took it up again for the 737.
Read my earlier post. The 727 fuselage is the same double-bubble as the 707/737. It's not circular.
It's a double bubble - top and bottom are cylinders of different radii with a floor to take up the difference in load - picture a round section pulled inward by the floor. It allows more width at the shoulder height of the passengers which allows more seats across the width. It probably requires a small weight increase over a circular section. For a large enough diameter it is less useful.
Thread Starter
Diagrams I have seen from various spotter books over the decades. I can't reproduce them here but the head-on view of the 707 and 737 are identical, i.e. double bubble or oval shaped and the 727 is a perfect circular section. Either the books are wrong or I am.
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The Stratocruiser also had the double bubble and in fact design studies to develop it into a swept wing jet transport led to the 367-80 "707" prototype, which retained the same diameter upper bubble as the Stratocruiser. The upper bubble width was increased for the C-135 and again for the 707 so there was space for six abreast seating.
Sad that I never flew on a 707/720.
Sad that I never flew on a 707/720.
The DH Comet was circular.
I think the Boeing 757 has the same section as the 707/727/737. It started life as a stretched 727 with a Tee tail and two rear mounted engines, then morphed into the aircraft we know today.
I think the Boeing 757 has the same section as the 707/727/737. It started life as a stretched 727 with a Tee tail and two rear mounted engines, then morphed into the aircraft we know today.
All the Boeing civil narrow bodies have a fuselage 148" wide and 158" high.
But don't take my word for it, take Boeing's:
.As for the KC-135 - it wasn't commercial...
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