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Correcting Altimiters? |
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Mar 11 2007, 08:53 PM
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Cessna 152 Member

Group: Newbies
Posts: 29
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Member No.: 4,998

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Hello, I own FS2004 and whenever I do a flight the altimiters are always set to 2992. Is there anyway to correct this? They are the incorrect altimiters. Thanks. Sorry for double post... I can change the altimiters manually, but it keeps telling me their incorrect.
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Mar 12 2007, 09:41 AM
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Space Shuttle Member
     
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The 2992 (1013.3Hpa) pressure you talk about is the internationally standard value for altitude pressure variance. This figure is vital to ensuring that every aircraft in the sky is flying on the same vertical scale
Wait up...what is transition altitude?. Basically it is simply a pre-determined altitude set in ink in your particular country. When below the TA you are subject to different rules than when above.
So why is the TA used? When in cruise the altimeter generally does not show an exact hight above sea level. Above the TA every pilot uses a default pressure setting not the exact pressure. This standard pressure of 2992 allows all aircraft to operate all on the same setting so that they are all operating on the same base figure. If one aircraft is at 23,000ft and the other is 24,000, both operating on the same pressure setting, 1,000ft of vertical separation is guaranteed. For this reason all aircraft fly on the same pressure in any given sector.
Above the transition altitude it is not important to know height above sea level exactly, but to know that all aircraft are making their decisions extending from the same set altimeter. Under the TA however an exact figure of AMSL (disregarding instrument error) is required. For this reason there can be no default value. What a pilot must do is enter the exact pressure setting in the area under the TA. All pilots again fly on the same setting, however now the setting is almost accurate to the ground. This pressure is known as QNH and can be found in two ways-
1)In controlled aerodromes and most registered OCTA airports, aerodrome terminal information service (ATIS) or an aerodrome weather service (AWS) will provide the local pressure.This figure is simply entered by all aircraft in the sector.
2) If however the local pressure is not available by a weather service a pilot can find the local pressure by setting the altimeter to the known ground AMSL. So if your on an aerodrome that is 230 ft AMSL set your altimeter to 230ft. Simple eh?
So to set the altimeters accurately follow the methods above or simply hit the shortcut key of 'B' i believe.
I apologize for the rant, it is late and i am bored....
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Apr 2 2007, 12:32 PM
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Cessna 152 Member

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QUOTE(cobzz @ Mar 12 2007, 04:10 AM) [snapback]114427[/snapback] Press B or D (Forget which one), that sets the altimetre to the correct pressure. press B
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Apr 6 2007, 06:04 PM
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Space Shuttle Member
     
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There are 3 altimeter 'measurements'. Inches of mercury (ISA (international standard atmosphere) value of 29.92 inches of mercury) Millibars (ISA value of 1013.2) Hectopascals (Hpa) (ISA value of 1013.2) As you can see, Millibars are on a 1 to 1 equivalent to Hectopascals. In the UK we use millibars, but hpa are becoming the standard in other countries. Of course, MSFS was made by Americans, so they only use their native setting- Inches of mercury. Gets annoying when flying online and being given pressures in millibars, despite the altimeter being in inches of mercury. And yes, I've changed the settings within FSX to 'hybrid' which gives feet and millibars as measurements, but still no joy
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Apr 7 2007, 03:53 AM
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QUOTE(c150student @ Apr 7 2007, 08:04 AM) [snapback]115494[/snapback] There are 3 altimeter 'measurements'. Inches of mercury (ISA (international standard atmosphere) value of 29.92 inches of mercury) Millibars (ISA value of 1013.2) Hectopascals (Hpa) (ISA value of 1013.2) As you can see, Millibars are on a 1 to 1 equivalent to Hectopascals. In the UK we use millibars, but hpa are becoming the standard in other countries. Of course, MSFS was made by Americans, so they only use their native setting- Inches of mercury. Gets annoying when flying online and being given pressures in millibars, despite the altimeter being in inches of mercury. And yes, I've changed the settings within FSX to 'hybrid' which gives feet and millibars as measurements, but still no joy  There is one key difference between millibars and hectopascals that you failed to mention. Hectopascals (Hpa) is an SI unit, milibars on the other hand is not. Milibars as you said is still accepted, but is commonly discouraged from use. Sure they both mean the same thing but in the modern day of science it is more about presentation than the actual science....
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Apr 12 2007, 11:39 PM
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Cessna 152 Member

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Posts: 29
Joined: 10-March 07
Member No.: 4,998

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Thanks very much guys...
I couldn't quite figure out why it was like that.
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