A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Piloting
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

GPS Altitude with WAAS



 
 
Thread Tools Display Modes
  #32  
Old October 1st 03, 04:52 AM
Ray Andraka
external usenet poster
 
Posts: n/a
Default

WIth my Six, I've found that opening the floor vent about half way and turning
the cup to the front avoids the hot foot while at the same time keeping from
freezing out the back seat passengers. Perhaps that would work in the smaller
CHerokees as well?

David Megginson wrote:

writes:

My Cherokee probably has the potential of keeping things warm, but
the air leaks elsewhere make it chilly. Seems like while your shoulders,
neck, and arms are freezing from a draft, you simultaneously smell burning
rubber from down by the rudder pedals....


I *feel* the burning down in my feet, even through boots and two pair
of socks -- that's why I eventually have to turn the heat down.

All the best,

David


--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email

http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759


  #33  
Old October 1st 03, 12:03 PM
David Megginson
external usenet poster
 
Posts: n/a
Default

Ray Andraka writes:

WIth my Six, I've found that opening the floor vent about half way
and turning the cup to the front avoids the hot foot while at the
same time keeping from freezing out the back seat passengers.
Perhaps that would work in the smaller CHerokees as well?


It sounds like a good idea -- I'll give it a try.


Thanks,


David
  #34  
Old October 2nd 03, 03:23 PM
Mike Rapoport
external usenet poster
 
Posts: n/a
Default

The pigs will be flying long before there is a 5F day at OAK.

Mike
MU-2


"Fred E. Pate" wrote in message
...
John Bell wrote:
Let me add two links to the discussion:

This is on problems with cold weather altimetry:

http://www.aircraftbuyer.com/learn/train06.htm

This is about the accuracy of unaided GPS altitude in the context of
vertical guidance, but it bears some relavence to the discussion of the
accuracy of GPS altitude:

http://www.bluecoat.org/reports/Graham_2001_RawGPS.pdf

John Bell
www.cockpitgps.com


This one's for the Canadians on this thread. A notice on the new
Oakland, California (KOAK) "RNAV (GPS) RWY 29" approach
(http://www.myairplane.com/databases/.../OAK_agr29.pdf):

"BARO-VNAV NA below -15 deg C (5 deg F)"

And this is for a decision altitude of only 294 ft AGL. Seems like the
FAA is moving towards taking into account temperature errors in
barometric alitmetry. And, by implication, this supports the premise
that WAAS altitude figures are more accurate than the trusty old
"sensitive altimeter." (In the legend they specifically state that
WAAS-based VNAV can be used when BARO-VNAV is not approved due to
temperature.)



  #35  
Old October 3rd 03, 07:53 AM
external usenet poster
 
Posts: n/a
Default

Sure, but that's not tne point. These restrictions will be standard on all of these types of approaches nation wide. Its the first time I am aware of that the FAA has included temperature altimetry errors in instrument procedures.

Mike Rapoport wrote:


The pigs will be flying long before there is a 5F day at OAK.

Mike
MU-2


"Fred E. Pate" wrote in message
...
John Bell wrote:
Let me add two links to the discussion:

This is on problems with cold weather altimetry:

http://www.aircraftbuyer.com/learn/train06.htm

This is about the accuracy of unaided GPS altitude in the context of
vertical guidance, but it bears some relavence to the discussion of the
accuracy of GPS altitude:

http://www.bluecoat.org/reports/Graham_2001_RawGPS.pdf

John Bell
www.cockpitgps.com


This one's for the Canadians on this thread. A notice on the new
Oakland, California (KOAK) "RNAV (GPS) RWY 29" approach
(http://www.myairplane.com/databases/.../OAK_agr29.pdf):

"BARO-VNAV NA below -15 deg C (5 deg F)"

And this is for a decision altitude of only 294 ft AGL. Seems like the
FAA is moving towards taking into account temperature errors in
barometric alitmetry. And, by implication, this supports the premise
that WAAS altitude figures are more accurate than the trusty old
"sensitive altimeter." (In the legend they specifically state that
WAAS-based VNAV can be used when BARO-VNAV is not approved due to
temperature.)






  #36  
Old October 3rd 03, 03:33 PM
Mike Rapoport
external usenet poster
 
Posts: n/a
Default

I agree in principle but in actuality it never gets cold enough in the US to
make a difference. The only times that we have really low temperatures (-40
and below) there is an inversion.

Mike
MU-2


wrote in message ...
Sure, but that's not tne point. These restrictions will be standard on

all of these types of approaches nation wide. Its the first time I am aware
of that the FAA has included temperature altimetry errors in instrument
procedures.

Mike Rapoport wrote:


The pigs will be flying long before there is a 5F day at OAK.

Mike
MU-2


"Fred E. Pate" wrote in message
...
John Bell wrote:
Let me add two links to the discussion:

This is on problems with cold weather altimetry:

http://www.aircraftbuyer.com/learn/train06.htm

This is about the accuracy of unaided GPS altitude in the context of
vertical guidance, but it bears some relavence to the discussion of

the
accuracy of GPS altitude:

http://www.bluecoat.org/reports/Graham_2001_RawGPS.pdf

John Bell
www.cockpitgps.com


This one's for the Canadians on this thread. A notice on the new
Oakland, California (KOAK) "RNAV (GPS) RWY 29" approach
(http://www.myairplane.com/databases/.../OAK_agr29.pdf):

"BARO-VNAV NA below -15 deg C (5 deg F)"

And this is for a decision altitude of only 294 ft AGL. Seems like the
FAA is moving towards taking into account temperature errors in
barometric alitmetry. And, by implication, this supports the premise
that WAAS altitude figures are more accurate than the trusty old
"sensitive altimeter." (In the legend they specifically state that
WAAS-based VNAV can be used when BARO-VNAV is not approved due to
temperature.)








  #37  
Old October 4th 03, 12:56 AM
external usenet poster
 
Posts: n/a
Default


Okay. But if you're on a precision approach you'll be below the inversion, no?

Mike Rapoport wrote:


I agree in principle but in actuality it never gets cold enough in the US to
make a difference. The only times that we have really low temperatures (-40
and below) there is an inversion.

Mike
MU-2



  #38  
Old October 5th 03, 12:33 AM
Fred E. Pate
external usenet poster
 
Posts: n/a
Default

Mike Rapoport wrote:
The pigs will be flying long before there is a 5F day at OAK.

Mike
MU-2


Oh yeah, I forgot to add that those pigs will be using WAAS and LAAS
equipment to make their approaches into Oakland when it happens

  #39  
Old October 5th 03, 12:39 AM
Fred E. Pate
external usenet poster
 
Posts: n/a
Default

Roger Halstead wrote:

It seems a bit strange...
.
DH on the ILS at MBS is only 200 feet AGL and that is with no
temperature correction. In the winter we regularly see below zero
F and it's not rare to see it at minus 20 at night


Yup, but temperature doesn't effect the glideslope, just where you put
the MAP along that glideslope. On the so-called "Baro-VNAV" approaches,
the glideslope is defined using barometric altimeter data, so the entire
glideslope will be shallower and closer to the ground on a cold day.
And if there is a low-level temperature inversion the glideslope won't
even be a straight line.

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Different WAAS altitude readings Wyatt Emmerich Instrument Flight Rules 21 June 29th 04 07:27 PM
GPS Altitude with WAAS Phil Verghese Instrument Flight Rules 42 October 5th 03 12:39 AM
USAF = US Amphetamine Fools RT Military Aviation 104 September 25th 03 03:17 PM
WAAS question -- altitude accuracy? Craig Davidson Piloting 10 September 23rd 03 09:56 PM
AOPA Stall/Spin Study -- Stowell's Review (8,000 words) Rich Stowell Piloting 25 September 11th 03 01:27 PM


All times are GMT +1. The time now is 11:18 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.