On 9/27/2011 9:54 PM, Beryl wrote:
Richard wrote:
On 9/27/2011 12:13 AM, Beryl wrote:
Richard wrote:
Do you know what would happen if the elevator were rigged for zero
trim at 500 mph?
...
What's the tradeoff?

Less efficiency at the speeds where most airplanes spend most of their
time, cruising along at ~70% power.


How about a 200 MPH landing speed?

X-15? What lands at 200 mph?

Not exactly a taildragger, is it?
Well, actually it sorta is - skids rather than wheels.
LOTS o drag on that there tail.


Are you saying that the Galloping Ghost, or Strega, couldn't be rigged
for minimum drag at 500 mph because they'd then have to land at 200?

Minimum drag, sure.

Zero drag, no.


Note that I never said the Stabilizer produces no nose-down force at 500
mph. I'm only doubting that the Trim Tab/Elevator are doing much work
there, at all. Set the Stabilizer to do the work, and lift (downward)
comes by way of Angle of Attack. But set the Trim Tab and Elevator to do
the work, and lift (downward) comes by way of Camber. And not even a
good camber, it's all zig-zagged and creased.

It's still drag.

And you can calculate how much will be there under any given conditions.