Originally posted by R_Mackey
I see Tom still hasn't read the Airdata And Calibration links provided for him numerous times.
You posted that link, in response to iSunTzu, here:
www.abovetopsecret.com...
You posted it, in response TO YOURSELF, here:
www.abovetopsecret.com...
You kids and your casual little insults & lies are bewildering to me, I gotta admit.
Nonetheless, I have read it carefully. And it simply reinforced the points that I made.
Originally posted by R_Mackey
Tom, you are partially correct with respect to a Cessna 172. Most of the errors you express are carefully examined and minimized in plumbing
chosen, length, location of ports. etc/
It's simple arithmetic to remove such errors once the variables are known.
Sorry, Rob, it is NOT "simple arithmetic to remove such errors".
Let's see if you can ACCURATELY define the math techniques that used to do this.
Let me help. They are called "e _ _ _ _ _ _ _ _ equations". And how do they typically generate them? And let's see you comment
intelligently on their accuracies & limitations.
Originally posted by R_Mackey
Over time, the aneroid wafers in altimeters wear, and therefore will not set to exact field elevation. This error does not wear/increase in one
flight. It takes years for an aneriod wafer to wear. Therefore the same error at take-off is the same error applied throughout the flight. Once
exceeding 75 feet, they then need to be either replaced or re-calibrated. Altimeters are required to be inspected and serviced every 24 months.
No, Rob. Anaeroid wafers do not "wear". They were specifically chosen for this application for two of their properties: 1. minimal hysteresis and 2)
no friction. "No friction" means "no wear", Rob.
Now, the capsules can change calibration, but for other reasons. And the whole instrument can be jarred - suddenly - out of calibration.
Originally posted by R_Mackey
Tom, how can a VSI be calibrated for instantaneous readings and free of errors, yet a PA be full of errors, when both sense pressure from the
same static port?
Surely, you're not really posing this as some mystery, are you, Rob?
1. Your premise is wrong. NO instrument is "free of errors".
2. No instrument is "instantaneous", although electronics are fast enough to be close. Mostly, IVSIs are only "instantaneous" in comparison to the
old style VSI's which depend on bleed orifices, and have significant lags.
3. Do you not know the difference between an absolute value and the "time derivative of that value" (aka "rate of change")? The absolute value can
be wrong, and the rate correct. The absolute value can be correct & the rate wrong. Or both can be correct. Or both can be wrong. Did you never take
freshman calculus or analytic geometry?
Tom
