On 4/17/2021 7:28 PM, John Martindale wrote:
Not always so simple. A number of pitot (not static) entry tubes on certified
aircraft, for example Mooneys, have a small drain hole at their lowest point to
allow escape of water. This is corrected for during calibration of the
indicator itself
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
As I stated in my post, this is not a "calibration" test but simply a
test to see it the ASI is functional. I suspect many ASI in
experimental are not all that accurate but an ASI, when not used to
collect data, is simply used as a "reference" anyway. Without
"calibration" how do you know you are going 100K's when it reads 100 but
you do know for example the airplane stalls when it reads "65K's",
whatever that speed happens to be. I seldom believe anyone when they
give a "touchdown" speed as the pitot tube is at such an angle as to be
inaccurate. I once took off without noticing my pitot/static was bent
off line by about 10 to 15 degrees. I suspected something was amiss at
about 50 feet altitude when I looked at the ASI. It was reading very
low. I lowered the nose a bit but continued the climb. When at pattern
altitude I departed the pattern and to test the ASI I went level at full
throttle. When it indicated only 110 mph I knew it was in considerable
error. I returned to the airport and landed without incident while
disregarding the ASI. I now tend to give it a glance during pre-flight.
Larry Flesner
________________________________
-Please see LIST RULES and KRnet info at http://www.krnet.org/info.html
-Change list delivery options at
https://list.krnet.org/list/krnet.list.krnet.org/ Affinity List Info Board
-Search recent KRnet Archives at
https://list.krnet.org/empathy/list/krnet.list.krnet.org/
-Search John Boyea's decades of archive at
https://www.mail-archive.com/krnet@list.krnet.org/
