I agree with Evan.

But why not get the guys at LXNav, Naviter,
LXNavigation, to call it arrival "height" and reserve
"height" if you must have it? Which imho is what it is
displayed, and this more precise terminology might
remove at least one source of confusion.

While you're at it, Waypoints have Elevation, perhaps.



At 14:08 26 May 2017, Tango Eight wrote:
On Friday, May 26, 2017 at 8:46:28 AM UTC-4, MNLou
wrote:
Hi Evan -=20
=20
Would you please expand a bit on why you think it is
better to set
reserv=
e altitude to zero?
=20
Thanks!
=20
Lou

Uh, sure. This is a semi-religious issue, so opinions will
vary. Here's
m=
y $0.02 on a rainy day:

Conditions vary. Airport environments vary. I happen
to fly in a region
o=
f the world (Northern New England) that features a lot
of terrain that
runs=
between poorly landable and completely unlandable,
and weather than runs
f=
rom benign to a crash-waiting-to-happen. While my
environment is more
chal=
lenging than many, yours isn't uniform, either.

So, the basic point is: there is no one standard reserve
height that is
app=
ropriate in all situations. You as PIC need to be making
decisions based
o=
n environment, current conditions & anything else that
affects safety of
fl=
ight. The computer is your assistant, not your decision
maker.

For example: At my home airport (also DC's home
airport) our traffic
patter=
n is high due to surrounding terrain and your final glide
ought to be
padde=
d well beyond this because there is simply no safe
place to land other
than=
the airport for a radius of about 5 miles (and then only
one or two
places=
, not necessarily where you want them!). Furthermore,
the "safe" (that
is,=
landable) route into my home airport follows a river
valley which often
fe=
atures a) valley winds and b) subsiding air. I'm usually
looking for
1500'=
over an MC 2.0 (kts) final glide from 25 out, based on
the airport
elevati=
on. When I was learning to fly XC here, it was more
like 2000 over.=20

This is total overkill at a million flat lands airports.=20

The obvious, simple solution is to set your flight
computer to report
estim=
ated arrival height at any destination without any
reserve, then do the
PIC=
decision making thing. For old Cambridge gear, that's
trivial. For
Clear=
Nav, there's one gotcha involved (easily handled, set
the purple amoeba to
=
zero and the red one to 1000 agl), for SN-10, you have
to build yourself a
=
whole new database with fake-news airport elevations
(yes, people really
do=
this, I've watched).

Go fast, make good decisions, land safe!

best,
Evan Ludeman / T8