Elevation Surprise

[fsc_ba]

I had just been trying to land with a 737 at mexico city and got into all sorts of trouble landing with elevation readings i assume i was set at sea level because i was flying way to low on approach and got in trouble over mountains.

Can someone explain to me how you set airport elevation s correctly as this has thrown me never seemed to have come across this before.

Any help would be appreciated thanks in advance

[Dwaffler]

Make sure you know the barometric pressure at the airport before setting up for a landing. Check the ATIS for the airport as soon as you can get it, even check surrounding airports.

 

BTW, you did know that Mexico City's airport is at 7300 ft in elevation!!

[mallcott]

I had just been trying to land with a 737 at mexico city and got into all sorts of trouble landing with elevation readings i assume i was set at sea level because i was flying way to low on approach and got in trouble over mountains.

Can someone explain to me how you set airport elevation s correctly as this has thrown me never seemed to have come across this before.

Any help would be appreciated thanks in advance

 

Regularly use the `B` key to re-set that setting. This is a must for operation at high altitude airports. Not to be forgotten at places like Manchester or elsewhere in the UK!!

[lnuss]

To expand a bit on Dwaffler's post, you set your altimeter to the barometric pressure, or altimeter setting, provided by ATC, ATIS, etc., which is actually the current barometer reading corrected to be sea level equivalent, which is what's needed to set the altimeter correctly for aviation purposes.

 

Then you must know the field elevation, just over 7K at Mexico City and Flagstaff, just over 5K at Denver and Albuquerque, 1500 at Phoenix, 600 at Joliet, Ill., etc.

 

There may be some confusion since the UK apparently uses two forms of altimeter setting, one which is as described above and one that will let the altimeter read 0 ft. on the ground at the airport. This latter form won't work anywhere there are higher elevations, since the Kollsman window/setting knob are limited in their travel, so cannot set a field at, say, 5000 feet above sea level (MSL) to read 0 feet, and it would take a while to set it if that much adjustment WERE available.

 

So the above is one of many reasons that aeronautical charts have field elevation on them, as well as elevations of mountain peaks, obstacles, etc., to aid in avoiding these obstacles.

 

In other words, it's the pilot's job to know terrain, obstacles, elevations, and other pertinent information.

[mallcott]

To expand a bit on Dwaffler's post, you set your altimeter to the barometric pressure, or altimeter setting, provided by ATC, ATIS, etc., which is actually the current barometer reading corrected to be sea level equivalent, which is what's needed to set the altimeter correctly for aviation purposes.

 

Then you must know the field elevation, just over 7K at Mexico City and Flagstaff, just over 5K at Denver and Albuquerque, 1500 at Phoenix, 600 at Joliet, Ill., etc.

 

There may be some confusion since the UK apparently uses two forms of altimeter setting, one which is as described above and one that will let the altimeter read 0 ft. on the ground at the airport. This latter form won't work anywhere there are higher elevations, since the Kollsman window/setting knob are limited in their travel, so cannot set a field at, say, 5000 feet above sea level (MSL) to read 0 feet, and it would take a while to set it if that much adjustment WERE available.

 

So the above is one of many reasons that aeronautical charts have field elevation on them, as well as elevations of mountain peaks, obstacles, etc., to aid in avoiding these obstacles.

 

In other words, it's the pilot's job to know terrain, obstacles, elevations, and other pertinent information.

 

The ASL altude is on the charts. Even in FSX.

Use them.

They're listed on the GPS, so there's no excuse...