Altimeter Setting

On 6/1/2010 9:16 AM, T8 wrote:
On Jun 1, 10:54 am, Bob wrote:

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

Bob... I think you need another cup of coffee.

-Evan Ludeman / T8

Heh...you may be right. I meant - of course - "Set the steenking
altimeters so they display relative to MSL at the time/location of
setting...from which you can then 'instantly derive' AGL from perusing
the chart you naturally have because you're a legal type of pilot, n'est pa?

Bob W.

On Jun 1, 8:26*am, bildan wrote:
*Professionals worked this out a long time
ago. *It isn't *up to us to figure out yet another way to do it.

Not picking on you Bill, but have to jump in somewhere. At least one
major US airline used QFE for all takeoffs and landings, at least up
until the time the MD-11 was designed and maybe they still do. I
believe they received the QFE setting from company ops. That
requirements added a lot of complication to the PFD altimeter
software, including a customer specific option to enable QFE setting
and all the logic required to quickly transition between the QFE, QNH,
and QNE settings . In the days before glass cockpits I think that
same airline had an extra altimeter dedicated to QFE operation.

So some people saw the value of QFE operations in USA.

I always set QNH but was trained to set QFE for local flights in
England.

Andy

I'm not sure what the fuss is about. I was taught not to use it for
landing but to judge the circuit by eye - after all I might land in a
field at a completely different altitude. (it read -500' after my
last field landing) 1013 is good if I get into wave so I know what FL
I'm at - there is airspace to avoid - though a good wave day often has
a QFE of 1013 where I fly.

I'm not sure what the fuss is about. I was taught not to use it for
landing but to judge the circuit by eye - after all I might land in a

It helps when communicating with other aircraft.

We can't set "Zero", we are too high in MSL, we can't "dial it down that
far".
What does the poor AGLr due when he visits another club or travels out west?
He needs to learn the "correct way" and learn to do the mental math.


"Rolf" wrote in message
...
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

if you set it to zero.. I field elevation is 1000MSL, so you are reading
1000ft low.
So how do you know when you are above 12500 for O2 rules..
and how do you know when you are going to bust 18000 Class A airspace..
your altimeter is 1000ft low.!!

BT

"Rolf" wrote in message
...
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

If you took off from an 8149ft MSL Mt Airport.. you can't set the altimeter
to zero without breaking it!!

"Bob Whelan" wrote in message
...


Fast forward to another mountain airport and another time... There I wuz
about to launch from a field at 8149' msl elevation, with a steenking,
howling crosswind of 20+ knots. Naturally, I didn't want to land right off
tow, so I decided I'd tow to 3,000' agl instead of my normal
2,000'...insurance against broken thermals and getting blown downwind away
from the only landable pace for miles around (i.e. the airport).

I pop off at what my poor overstressed brain said was 3000' agl, known
that instant to be an indicated 10,150' (I rounded up 'for safety's
sake'!), in a decent-feeling upwelling and begin grinding around, keeping
a beady eye on my drift relative to the field. I begin climbing too, but
for some reason I couldn't get comfortable as fast as I thought my climb
rate should be permitting...something about that lurking ground bugged me.
About 500' into my climb I realized it was because the ground was WAY too
close for being 3500' agl. Apparently my instructor had been right about
my 'puny overworked brain' all those years ago!

Andy,

You are correct. Several US airlines used to use QFE for takeoff
and landing. (Eastern and American). 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. Plus they
had enough pilots from other carriers and military saying, "why are
you doing this?" . i.e. Takeoffs and landings had 2 altimeters set at
QFE and one at QNH. The practice also became absurd once radar
altimeters became standard equipment. (they read AGL). My airline has
used QNH from the beginning. Less chance for errors because of fewer
large altimeter corrections. Of course an altimeter setting 28.xx
instead of 29.xx can create an issue!
Back to gliders. Anyone who can't do the math(MSL) shouldn't be
flying gliders or anything. Period How tough is the math really? I
learned to fly in power aircraft.(general aviation-always use QNH).
Gliders don't have radar altimeters but pilots have Mark 1 eyeballs to
figure out high/low/on glideslope early in their flying career. This
thread has been fun to follow. The reliance on PDAs is just another
distraction for pilots. I suppose one can rely on them for altitude
information but it defeats the purpose of enjoying soaring for simple
and elegant flying if we are fixated on instrumentation and gadgets to
figure out if we are high or low.
Its a good reminder. We need to be vigilant for traffic at all
times. Don't fixate on altimeter/PDA. Look at the terrain and have
fun.

Aloha, Dean

On May 31, 10:14*pm, 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).

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