Date: 16 Sep 97 02:35:25 From: jf mezei <"[non-spam]jfmezei"@videotron.ca> Organization: VTL References: 1 Followups: 1
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Mark E. Ingram wrote: > An _AvWeek article of three or four years ago stated flatly that Boeing > aerodynamicists were totally surprised when the longer hump of the first > "extended upper deck" 747 (the -300) caused a *decrease* in drag over the > original design. Can anyone comment on (or verify) this? (speculation) If the hump of the SUD "fades" over a longer distance, and the hump of the -200 ends more abruptly, I would *assume* that airflow disruptions would be lessened. I would also speculate that on the SUD, there is a long enough section of "smooth" fuselage where the disruptions caused at the front of the hump have time to smooth out a bit before the disrubtions caused by the end of the hump occur. Is this a fair appraisal ? Or totally out of wack ? ... But if the hump actually reduces drag, how come other Boeing planes which were designed afterwards (767,777) don't have a hump too ?