From Gerry Nolan
You report that Boeing found “that the two-hump design unexpectedly decreases
drag” for jumbo jets
(10 June, p 9).
They should have realised that this would be the case.
For at least 50 years, high-speed aircraft have been designed with
“waisting”, usually called the “coke bottle” shape, to reduce drag. That is, the
fuselage is made narrower where the wings are attached. It works because the
resulting aircraft presents a more smoothly increasing cross section to the
airflow instead of a sudden large increase where the wings are.
The two-hump aircraft with the dip over the wings would have the same effect
as waisting, thereby reducing drag. One would have thought even the Boeing
flacks would know this.
Sydney
