Barometric pressure question

In FSX and even FS2004 I have to constantly hit the B key (yeah, I cheat) to correct the barometric pressure. It varies greatly withen at least 30 miles or so. I use the Active Sky 2016 weather engine and despite its greatness that I can tell, I have large variances with pressure. Is this true in real life as well? I wouldn't think so, and in fact I think it might vary by just a few millibars withen about 100 to 200 miles at least. Or am I wrong? Does the pressure really change greatly withen about 30 miles? And if that's the case how in God's name do you maintain a constant and consistent altitude! LOL There's no B key in the plane after all.

 

Which brings me to my next question: Do you tune to the nearest ATIS or ASOS, etc every now and then to correct your pressure setting? Speaking in terms of most VFR flights under the U.S. transition altitude of FL180.

Barometric pressure can, indeed, vary quite a bit, even just a handful of miles apart, depending on conditions. There may be times when here at the house I'm within a couple of hundredths of an inch of Jeffco (now Rocky Mountain Metropolitan- KBJC), about 6 miles southwest of me, and there are other times when I may be .20 or more (even .50 on rare occasion) off of their report.

 

And I've flown (real life) from, say, Erie to, say, Centennial and had a considerable pressure change, even some difference from Erie to Jeffco.

 

How much change there is varies depending on where the lows and highs are, how strong they are, how fast they are moving, and other factors too. So I rarely find FSX or P3D unrealistic in that respect, except when they maintain the same pressure for too long a distance.

 

Does the pressure really change greatly withen about 30 miles? And if that's the case how in God's name do you maintain a constant and consistent altitude!

 

Again, depends on conditions. As to maintaining altitude, you're hopefully flying with the same altimeter setting as everyone around you, so you just refer to your altimeter (or tell "George" to hold it).

 

As for your question about ATIS/AWOS, I don't usually care about that part of realism that much, so if I need the altimeter set properly I use the 'B.' So it really depends on how "real" you want to be, since there is no 'B' key in real life.

 

But in real life, I'll usually use my departure altimeter setting for a while, unless I'm talking to ATC when I'll use whatever is specified for that area (ATIS or ATC report), then listen to various weather stations as I go along. However, I already have some idea of what the pressure is doing on my route prior to departure, since I get a weather briefing and usually get to also see a weather map with isobars on it.

 

Keep in mind with all the above, I'm not doing this airliner style, but rather "general aviation style" so I'm not IFR very often, especially in the sim (unless I want to practice IFR approaches).

Okay, thanks. I guess you have a map with the isobars and as you move into that area you correct the altimeter? If so, can I get such maps to compare in the Sim? Or is that a paid for product?

Okay, thanks. I guess you have a map with the isobars and as you move into that area you correct the altimeter? If so, can I get such maps to compare in the Sim? Or is that a paid for product?

 

Not that way. A map such as the one below from a government aviation weather site:

 

 

A really stormy one will almost look like a topo map in some areas, since the isobars are so close together in certain conditions. And you certainly can't set your altimeter from that. It just gives you an idea of what kind of changes to expect, but you still need to get the altimeter setting from ATIS/AWOS or from the Flight Service Station or ATC. The map shown here is for pretty mild changes, and is a surface prognostication chart, not current conditions, which are constantly changing.

 

You can see more about it in the FAA's Pilot's Handbook Of Aeronautical Knowledge Chapter 13 - look at page 14. There's a wealth of information available on the FAA's site that you can study to learn about this stuff.

 

Or if you want the easy way, use the 'B' key.

 

Today there are services which will let you access such stuff in flight, but that's a fairly recent thing (last 20 years or so).

And remember, when flying above 18,000 feet, set the altimeter to 29.92 (or 1013 mb).

Not that way. A map such as the one below from a government aviation weather site:

 

[ATTACH=CONFIG]203397[/ATTACH]

 

A really stormy one will almost look like a topo map in some areas, since the isobars are so close together in certain conditions. And you certainly can't set your altimeter from that. It just gives you an idea of what kind of changes to expect, but you still need to get the altimeter setting from ATIS/AWOS or from the Flight Service Station or ATC. The map shown here is for pretty mild changes, and is a surface prognostication chart, not current conditions, which are constantly changing.

 

You can see more about it in the FAA's Pilot's Handbook Of Aeronautical Knowledge Chapter 13 - look at page 14. There's a wealth of information available on the FAA's site that you can study to learn about this stuff.

 

Or if you want the easy way, use the 'B' key.

 

Today there are services which will let you access such stuff in flight, but that's a fairly recent thing (last 20 years or so).

 

Thanks.

 

Yeah, satellite services is a really big thing. I can only imagine ACARS being a thing of the past, although, a great backup. I wish I had the money to invest in some of these Sat airline companies, and especially when NextGen comes online. I have read that even the radio will change to digital, though I'm not too sure on that. It may be some sort of P25 protocol codec like what a lot of public safety uses now a days. Which means ours Sim at present will be very obsolete. :D

And remember, when flying above 18,000 feet, set the altimeter to 29.92 (or 1013 mb).

 

I do know that. Figured that out myself about 8 years ago when ATC kept screaming at me about not being at my assigned altitude. In fact, I figured a lot of things out myself. Like ILS, etc.

 

Good thing that's standard in the entire FS world. To me personally, I don't want to have to look up what the transition altitudes are in other countries. I fly around the world quite often. Been around the blue marble 4 times now.

Another good reason to request VFR flight following is that the controllers will give you local altimeter settings without you needing to pull up ATIS.