Altimeter Setting

On 2010/06/01 04:54 PM, Bob Whelan wrote:
ybe I was just an idiot that particular day. Also, I like to think I'd'a
entered the pattern 'by eye' and not at 0' agl had that thermal not
worked for me.

Legality aside, use agl...*please!!!*

Flying's real safe so long as you don't inadvertently hit anything.
Though I don't know this for a fact, I'll bet my retirement that at
best, it'll be embarrassing to inadvertently hit the earth when your
'field level' altimeter suggests you're still OK.

Bob - sometimes 'common sense' isn't - W.
My Std Cirrus has an elegant solution - lots of panel space.
2 Altimeters. The metres one is set to QFE. Then I at least have some
idea how high the target should be on the final glide, iff the barometer
has not moved too much... Helps my puny brain.

The "legal" feet altimeter is always set to show MSL.

Bruce

--- news://freenews.netfront.net/ - complaints: ---

OK.. MSL it is......But.......

There's a lot more to the story!

Funny thing, where is REALLY matters, (collision avoidance) MSL is not
used.........such as transponders, PCAS etc.....they use pressure alt,
as does IFR flight above 18,000. Also flight recorders use pressure
alt. Acrobatic pilots tend to use alt setting zero, since they want
to know exactly where the ground is without doing math.

Of course all the "experts" say that glider landing, especially off
field landing, MUST be done by "visual reference to the ground" not by
altimeter at all.

Then there's

Absolute altitude
Calibrated altitude
Radar altitude
GPS altitude
All that "Q" stuff
Field elevation
So called, (but incorrectly) AGL (really should be "above starting
point" as the ground varies as soon as you move!)
Non standard pressure lapse rates
Flight for high to low pressure, flight from hot to cold, etc
Mean sea level
Altimeter error....(anybody know how much error is allowed?)(anybody
ever go around te airport and note the differences from one altimetier
to the other?)

Sensitive altimeter, non sensitive altimeter?

Then how about "metric" altimiters? 300 meters per revolution
How about altimeters with the "zero" on the bottom

So.... I trust that all you instructors teach all of this and more to
your first-lesson students....don't leave ANYTHING out... law of
primacy and all that.....

Cookie

On Jun 2, 11:27*am, "
wrote:
snip

Of course all the "experts" say that glider landing, especially off
field landing, MUST be done by "visual reference to the ground" not by
altimeter at all.
snip

Why put experts in the above in double quotes? Do you doubt that a
field landing should be done by visual reference?

On Jun 2, 7:16*am, Cats wrote:
On Jun 2, 11:27*am, "twocoolglid...@juno. com wrote:

snip

Of course all the "experts" say that glider landing, especially off
field landing, MUST be done by "visual reference to the ground" not by
altimeter at all.

snip

Why put experts in the above in double quotes? *Do you doubt that a
field landing should be done by visual reference?

No, I quoted "expert" because the same guys who are so big on
altimeter setting say don't use the altimeter on landing. I am of the
school that says the altimeter is not all that important, (in most
common glider flying) so where you set it is not all that important
either........you gotta do math in your head one way or the other!

My overall point was that in situations where it really matters, like
off field landings, the altimeter is not useful. Also MSL is not the
"datum" used in collision aviodance.

BTW "" double quotes"" would look like this "quotes" look like
this.......LOL

Cookie

Just to play devil's advocate on this "zero altimeter" thing.........

Here is a scenario.....

Your kid is running in a one mile track race........you want to time
the race.......

The race begins.....you look at your watch....the time is 12:30:
26.010

As your kid crossed the finish line you look again at you
watch...........12:35:49 070

How fast did the kid do the mile?

Now, when my kid starts the race, I had my watch set at 0:00:00.000

At the finish it reads.......5:23.060..........done! no math!

Altimeter is a TOOL.......tool's are for the ease of use of the
user.......My tools work for me, I don't work for my tools. Tools can
be used in different ways for different purposes. Using MSL on the
altimeter does serve a good purpose for many situations, but not
all........

Cookie


Cookie

On Jun 2, 12:39*pm, "
wrote:
snip

BTW * "" double quotes"" would look like this *"quotes" look like
this.......LOL

No, those are double double quotes.
The Single quote character is this: '
The Double quote character is this: "

Double quotes (plural) as you had two of them - one each end of
expert.

On Jun 2, 7:47*am, "
wrote:
Just to play devil's advocate on this "zero altimeter" thing.........

Here is a scenario.....

Your kid is running in a one mile track race........you want to time
the race.......

The race begins.....you look at your watch....the time is 12:30:
26.010

As your kid crossed the finish line you look again at you
watch...........12:35:49 070

How fast did the kid do the mile?

Now, when my kid starts the race, I had my watch set at 0:00:00.000

At the finish it reads.......5:23.060..........done! no math!

Altimeter is a TOOL.......tool's are for the ease of use of the
user.......My tools work for me, I don't work for my tools. Tools can
be used in different ways for different purposes. *Using MSL on the
altimeter does serve a good purpose for many situations, but not
all........

Cookie

Cookie

So what do you do when on a XC flight, not particularly high, and
encounter class D airspace that you'd like to fly over?

-T8

On Jun 2, 12:38*am, (Alan) wrote:
In article 150flivver writes:

On May 31, 10:14=A0pm, GM wrote:

Rolf, if memory serves me right, the FARs are clear about it: setting
to MSL is required.

I don't recall any regulation requiring the altimeter to be set to QNH
unless the particular operation requires it (eg. an instrument
approach).

* 14 CFR 91.121 * (aka FAR 91.121)

* For extra credit, note 91.121(a)(1)(i) which says you must use the setting
from the local radio source in preference to setting to the field elevation.
As was pointed out in this group a couple years ago, the examiner in the back
seat knows that regulation.

* * * * Alan

Yeah, but as for 91.121 you're not maintaining any particular cruising
altitude or flight level when operating a glider. I certainly agree
that cross country gliders should be operating off QNH but if you're
flying locally, you should have the option of setting QFE. I fly a
towplane and use QFE 99% of the time--any position calls I make I
convert to MSL (I have a table to reference on my legboard). If I
have to go and retrieve a landout, I'll use QNH.

"Yeah, but as for 91.121 you're not maintaining any particular
cruising
altitude or flight level when operating a glider. "


The FAA legal department told me they recognize the problem /
confusion with the English language usage used in the regulation.
Gliders do not "cruise." However, the intent of the rule is clear.
Glider pilots must be aware of airspace altitude restrictions
including aircraft cruising.

Recognized exceptions to setting the altimeter to MSL include crop
dusting and aerobatics.

Yesterday, there was a very close near-miss with a glider and
commercial jet descending for a landing. The club where the glider
flies commonly uses and teaches using AGL altimeter settings.

It will only take a very few of these encounters for gliders to be
required to have ADS-B transponders and perhaps be banned from certain
airspace near airports where larger aircraft fly altogether.

A new, highly accurate GPS satellite was launched yesterday. First of
a series leading up to the new transponder technology.

Tom Knauff

On Jun 1, 6:11*pm, Dean wrote:
American stopped the practice
when Boeing told them they wouldn't build those funky altimeters(mucho
twisting up and down each takeoff and landing) for the B777.

That's interesting since the same company designed and built the
display systems for both the MD-11 and the 777 and that company knew
how to make a QFE altimeter work very well on a PFD. Hardly any
twisting at all required for the MD-11. Maybe it was the old NIH
syndrome, DAC vs Boeing.

Andy