----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----
We have seen a lot of 30+ year old
airspeed indicators giving falsely high airspeed readings. It could be
worth checking that first, both at cruise speed and down near minimum flying
speed.
Though it would be interesting to find out
what other Alon owners get in their flight tests the ultimate test is what YOU
get in your flight testing.
You might want to go out and do some
serious flight testing, timing a 2,000’ climb at every airspeed from
close to minimum up to a cruise climb.
If you (or some lurker) get the urge to do
the testing, here’s a procedure:
To compute the angle of climb, you need to
know the true airspeed (not indicated). That needs a reliable airspeed
indicator combined with altitude and temperature so you can convert indicated
airspeed to true airspeed. Then, figure that your forward speed in feet per minute is 88
times the true airspeed in mph.
I’d suggest starting each run at
1,000’ agl and stabilize your climb for 500’. Then, time it
with a stopwatch from 1,500’ agl to 3,500’ agl while you
concentrate on nailing the test airspeed (or convenient msl numbers). Record
the temperature at the mid-point of the climb on each run. Then, cool off
the engine gradually before you descend for the next test run.
I’d do the test runs at every 5 mph
from minimum up to about 90 mph so you have a complete profile of your plane’s
climb performance.
I found it helps to have a co-pilot along
to record data while I concentrated on smooth and accurate flying.
The best angle of climb is the speed where
climb
rate in feet per minute divided by forward speed in feet per minute is the
largest.
(The glide testing procedure is similar.)
Ed Burkhead
http://edburkhead.com
ed -at-
edburkhead???.com (change
-at- to @ and remove "???")
============================================================================== To leave this forum go to: http://ercoupers.com/lists.htm
