Tuesday, September 15, 2009

C-133 Design Questions

Last night, I talked for more than an hour with Don Elder, who was an aerodynamics engineer at Douglas. He worked the YC-124B and the C-133. I asked him about several questions that had come to me.

1. Why did the wing have a 12-degree angle of incidence?
This was because the aft fuselage was so long that, with a smaller AOA, the tail upsweep would have had to be much steeper. Increasing the AOA allowed less upsweep from the bottom of the fuselage to the tail cone.

2. The wing seemed to be located much farther aft that on other airplanes.
The important design consideration is the fore-and-aft relationship of the wing and the tail. The portion forward of the wing could be as long as necessary.

3. Were 4-bladed props ever considered?
Yes, they were. But, they presented a much larger flat-plate area than the 3-bladed props from (per Don Elder) the Curtiss toy company. The three-blade props were more efficient.

Cal Taylor

2 comments:

Papa Hans said...

FASCINATING,Cal. Thanks for sharing. Can we get Don Elder hooked into our blog? Does he do e-mail? Would he be willing to answer questions from our Crew Colleagues?

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