Altimeter Setting

Over the years (30 or so) Caesar Creek Soaring Club has vacillated
with setting the altimeter to zero or MSL. Last year the Board decided
to put the Club ships on an MSL basis (private gliders exempted).
There are however a number of members who are continuing to make it an
issue. I would be interested in your thought and comments.
Thanks
Rolf Hegele
CCSC President

On 5/31/2010 7:07 PM, Rolf wrote:
Over the years (30 or so) Caesar Creek Soaring Club has vacillated
with setting the altimeter to zero or MSL. Last year the Board decided
to put the Club ships on an MSL basis (private gliders exempted).
There are however a number of members who are continuing to make it an
issue. I would be interested in your thought and comments.
Thanks
Rolf Hegele
CCSC President


It seems to me it would make a lot more sense to use MSL, as then the
elevation on the altimeter will correspond to the elevations on the
sectionals and other charts and maps. What is the rationale for using AGL?

York Soaring in Ontario, Canada just switched over to MSL for the club
operations after using AGL for so many years. It was hotly debated
with arguments on both sides.

AGL is great for basic training. We teach the circuit based on AGL:
800'-1000' at the IP to start the circuit, turn base at 400'-600' and
turn final at 300'-500'. Real quick and simple, just read it off the
altimeter with no math conversion. Minimises the mental load on a
student pilot.

Causes minor problems in operations, though:
- xc pilots work on MSL but the club ships were AGL, so moving the
dials back and forth
- pilots confusing MSL vs AGL readings
- power pilots are on MSL, people would confuse heights given over the
radio, thinking it was AGL

As a concession to those firmly entrenched with AGL, we've put printed
stick-on rings around the altimeters that has AGL markings specific
for our club. The thousands pointer indicates zero AGL when set to
field elevation.

On May 31, 7:28*pm, Greg Arnold wrote:
On 5/31/2010 7:07 PM, Rolf wrote:

Over the years (30 or so) Caesar Creek Soaring Club has vacillated
with setting the altimeter to zero or MSL. Last year the Board decided
to put the Club ships on an MSL basis (private gliders exempted).
There are however a number of members who are continuing to make it an
issue. I would be interested in your thought and comments.
Thanks
Rolf Hegele
CCSC President

It seems to me it would make a lot more sense to use MSL, as then the
elevation on the altimeter will correspond to the elevations on the
sectionals and other charts and maps. *What is the rationale for using AGL?

There is absolutly no rationale for setting the altimeter to AGL.The
only excuse I am willing to accept, and it is a rather poor one, if he
or she would NEVER EVER be willing to be out of glide to their home
field. And how many glider pilots were NEVER EVER in that position? 6PK

On May 31, 8:22*pm, PK wrote:
There is absolutly no rationale for setting the altimeter to AGL.The
only excuse I am willing to accept, and it is a rather poor one, if he
or she would NEVER EVER be willing to be out of glide to their home
field. And how many glider pilots were NEVER EVER in that position? 6PK

Not even that!

What if the pilot hears a radio call such as "Airport XYZ traffic,
Cessna 1234, 2 miles south crossing midfield at 2500"?

Where will he be looking? Up? Down?

When I flew at CCSC 18 or so years ago, I would set the club ship's
altimeter to the CORRECT setting, and let the next pilot deal with it.

-Tom

Rolf wrote:
Over the years (30 or so) Caesar Creek Soaring Club has vacillated
with setting the altimeter to zero or MSL. Last year the Board decided
to put the Club ships on an MSL basis (private gliders exempted).
There are however a number of members who are continuing to make it an
issue. I would be interested in your thought and comments.
Thanks
Rolf Hegele
CCSC President


The English way is (or at least was) to set QFE for landings and
takeoffs, and to set QNH at (if I remember) 3000 ft. The station baro
setting for QFE was transmitted on arrival at destination. En-route, the
forecast QNH was used. Both settings were provided in millibars.

Oh, I should translate QNH to mean a baro setting = 0 ft "Altitude" at
mean sea level and QFE baro setting reads 0 ft "height" at station
elevation.

The American way is to use QNH until at flight level altitudes the
pressure altitude setting of 29.92 inHg comes into play.
The American way minimizes screwing around with baro settings: a current
QNH value may be obtained by tuning ATIS, AWOS etc. frequencies en route.
The English way can I suppose lead to better pattern altitudes
( = circuit heights) because they can always be 500 ft, 1000 ft,
or 400 ft., 800 ft indications.

The American way involves descending to a pattern altitude as given by
elevation (from the chart) + pattern height. At Altus for example, that
would be 1433 + 1000 ft


For what it's worth...


Brian W

They must all decide if they wish to be airmen or mere pilots. Those
wishing to select zero are lazy and don't want to think or maintain an
acceptable level of airmenship. Those who allow such practice are
tired of beating a dead dog to fetch a bone.
Here's the thing.... when the canopy closes, who's to know. The
individual is still responsible for his performance.
The club should establish the level of expected performance and
standard operating procedures. This level must be high knowing that
some individuals will slack off 20+%. Training to 95% - 20% is just
within acceptable levels. But train to 80% , well now you have to have
good insurance and extra gliders.
The good side of weak requirements is the increase demonstration of
Darwins theory of Evolution and the improvement to the gene pool.
Wait till someone has to tell the old geezers they fly like crap and
no longer are allowed. They won't be thinking MSL anymore.
30 years to decide, huh? All of you should go back to school.
Who the hell is in charge?
R

Rolf,

From the inception of the club to about 5 years ago, we flew and
taught AGL only. No self respecting power pilot would fly AGL.
Flying AGL is a crutch intended to help new pilots. But It is better
to learn it right from the get-go than to have to relearn it later and
maybe getting into an accident.

So about 5 years ago my Club's flight chair said that flying AGL was
wrong, dangerous and (if I am not mistaken) illegal. So the board
made an edict and we changed overnight at the start of a season. We
marked all altimeters in club ships "MSL Only Club Policy". There was
some, but not a tremendous amount of, consternation ... such as "But
it is so flat around here." or "But I always land back home."

We did have one incident related to the AGL/MSL switch that might be a
good to read about. One day yours truly flew a club ship and set the
altimeter to MSL. The next pilot was an die hard AGL'er. The AGL'ers
were used to finding the altimer not quite at zero due to barometric
changes and would "tweak" the altimeter to zero at the start of each
flight. Our field elevation is 888 feet. So the next pilot tweaks
the altimeter to "zero" but instead of subtracting 888 feet (by moving
the hands CCW), he tweaks it CW and adds 112 feet! Can you see where
this is going?

He then takes a tow to what he thinks is 3,000 feet AGL but is only
really at 2,000 feet AGL. The tow pilot doesn't think much about it
as people get off tow early all the time. About to enter the pattern
the AGL'er thinks, "Gee, the ground seems to be kind of large
today ... but I am still at 1500 feet AGL so I'm must be OK." He then
almost lands short as he was 1,000 feet lower than he thought. End of
story? Nah.

The AGL'er gets back on the ground and complains that the altimeter
must be wrong. We look at the altimer and see that it is showing
1,000 feet. Putting 2+2 together we figured out what he did. So get
this ... an old timer CFIG says it was my fault as I should have reset
the altimeter to zero when I got out. Sorry, wrong-o. Who was the
PIC on the second flight? The AGL'er of course. It is his
responsibility to ensure that the instrumentation is set correctly,
not mine. Can you tell that it still grates a bit? Ok, I feel better
now.

Anyway, my suggestions are to;

1) Do it!
2) Convert "big bang" all at once, not by dribs and drabs or over a
"transition" period.
3) Mark the altimeter with an "MSL Only" sign to reenforce the new
policy each time a pilot climbs into the cockpit.

Good luck, John DeRosa

PS Early in my soaring career, I remember flying at a commercial
operation while on a business trip and was told to set the altimeter
to MSL. I started sweating worrying about all the math I would need
to calculate in my head. Luckily I was in Miami at the time and the
field elevation was all of 20 feet - not much of a problem.

On 5/31/2010 8:06 PM, ContestID67 wrote:


He then takes a tow to what he thinks is 3,000 feet AGL but is only
really at 2,000 feet AGL. The tow pilot doesn't think much about it
as people get off tow early all the time. About to enter the pattern
the AGL'er thinks, "Gee, the ground seems to be kind of large
today ... but I am still at 1500 feet AGL so I'm must be OK." He then
almost lands short as he was 1,000 feet lower than he thought. End of
story? Nah.

The poor guy couldn't tell the difference between 500' AGL and 1500' AGL
by looking out the window? Sounds like it was time to retire his wings.

On May 31, 11:22*pm, Greg Arnold wrote:
On 5/31/2010 8:06 PM, ContestID67 wrote:



He then takes a tow to what he thinks is 3,000 feet AGL but is only
really at 2,000 feet AGL. *The tow pilot doesn't think much about it
as people get off tow early all the time. *About to enter the pattern
the AGL'er thinks, "Gee, the ground seems to be kind of large
today ... but I am still at 1500 feet AGL so I'm must be OK." *He then
almost lands short as he was 1,000 feet lower than he thought. *End of
story? *Nah.

The poor guy couldn't tell the difference between 500' AGL and 1500' AGL
by looking out the window? *Sounds like it was time to retire his wings..

Here's a good one. I usually fly out of a busy general aviation
airport right on the edge of Class C airspace. We are surrounded by
mountains, talk to power planes and controllers, and fly cross country
a lot, so we always use MSL. Recently I spent a sunny afternoon down
at the local gliderport where they do a lot of training. I took a tow
to the ridge and got off at about 3,200 (MSL). Much later that
afternoon, the owner was up flying so I asked someone what I owed for
the tow. They asked me how high I went and I said "3,200 feet." A
quick look at the handy chart on the wall told me what I owed them for
"3,200 feet" and I happily paid and left. On the drive home I was
musing about how the price of tows was always going up, but who cares
when the planes and gadgets cost so damned much. Then it hit me WHY
they were going up. The gliderport uses AGL for training AND to
calculate the tows to simplify the billing, and I hadn't deducted the
field elevation when I told him "3,200 feet." I had bought about 800
feet of it sitting at the end of the runway waiting to hook up. All
I could do was laugh at myself, and they are welcome to the tip for
all they do for all of us. At least I hadn't scratched around cross
country for two hours with my gear down like I usually do... Now THAT
****es me off!

Don