I still that sounds like a lot to accomplish while picking a spot,
checking mags, carb heat,
mixture, fuel, checking wind direction, notifying someone on the
ground, and, oh yes,
flying the airplane. I've had two engine failures and didn't need a
gps screen to add to my workload.
Dan Caliendo
Ercoupe Mach 0.14
3658H
On Jan 21, 2009, at 1:41 PM, David Winters wrote:
The GPS-196 includes a really neat glide-ratio automated
calculation and display, if you select it. In fact, if you select
a target, it will tell you whether your glide will reach it… or
not. By coincidence, while taking some review lessons last night,
I discovered this ability and created one screen that displays ONLY
this information. It shows four big blocks on the screen. They are
GLIDE RATIO
GLIDE RATIO TO TARGET (required to reach the target)
COURSE TO TARGET
HEADING TO STEER (to target)
PROCEDUE TO CREATE THIS PAGE;
Go to the numerical data page. (one of only 4 main pages)
PRESS “MENU”
SELECT “SET UP PAGE LAYOUT”
“ENTER”
SELECT “4 BIG FIELDS” OPTION
“ENTER”
PRESS “MENU”
SELECT “CHANGE DATA FIELDS”
“ENTER” TWICE
SELECT ONE OF THE FOUR BLOCK TITLES ABOVE FOR EACH BLOCK IN TURN
“ENTER” FOR EACH BOX AFTER SELECTING
PRESS “QUIT” TWICE
Now you have an emergency glide display screen. You can keep it as
one of your four main pages OR you can preserve it as an option for
call-up only when you need it.
In an emergency, if you have a desirable landing point available on
the GPS, just select it as your destination and then bring up your
nifty “glide screen”. It will tell you in short order if you can
reach your target, and it automatically includes field altitude in
that calculation.
(I do realize, of course, that if you find yourself without power
and only a couple of thousand feet up, other issues will probably
be more urgent.)
This screen is also handy just for finding out what is your best
distance glide-speed.
Note that it does not tell you how to stay in the air for the
longest time. It only tells you how to glide the longest distance.
I suppose this ability must also be available on the 296, 396, and
496, but I did not confirm it.
Dave Winters
-----Original Message-----
From: [email protected] [mailto:ercoupe-
[email protected]] On Behalf Of Ed Burkhead
Sent: Wednesday, January 21, 2009 1:07 PM
To: [email protected]; ety
Subject: [ercoupe-tech] Coupe glide ratio
Darick,
Clever idea, doing the measurement like that. It could give a
useable number.
Was that all at idle power? A confounding factor is that turns use
energy and the steepness and radius of the turns determines how
much energy is lost in the turn.
However, that 8.5:1 ratio sounds like the ballpark glide ratio for
the Coupe.
The only really careful and accurate glide ratio testing I’ve heard
of in the last 30 years was mine and it was all bollixed up due to
the airspeed indicator I didn’t know was faulty.
The numbers I got were in that range too (after making guestimate
adjustments for the ASI error), perhaps, better at a bit higher
airspeeds.
Your estimate of 8.5:1 is consistent with my best guess for glide
ratio for around 70-80 mph.
If someone would like to do rigorous glide ratio testing, here is a
pretty good procedure – the old fashioned way. It’s kind of
tedious, but that’s what’s needed for rigorous testing of something
like glide ratio.
http://edburkhead.com/Ercoupe/performance_information.htm click on
glide ratio testing.
Some new electronic instruments will give a continuous readout of
glide ratio based on altitude, temperature, indicated airspeed and
altitude. My Stratomaster Extreme instrument package claims that
ability but it’ll be in my Challenger if I ever get that finished.
For that matter, my Garmin GPS will also give a glide ratio
readout. I bet many other good GPS units will do that, too.
Hope several of you do some testing at various airspeeds and report
the details (including details of your plane and its special drag
features [venturi, landing gear fairings, landing gear mounted
landing lights, etc.]).
Hummmmm, the idea of doing this testing with a glide ratio readout
GPS really sounds tempting. Go, people, Go!
Ed
