Converting QFE to QNH Rule of Thumb

[EtherealN]

Really? I was always instructed in terms of AMSL and AGL not Q--. This was about 15 years ago so I'm not sure if the teaching terminology has changed since then.

 

same here. I went to flight school in New Jersey back in 1998 and got my PPL in 1999 and the only thing I was taught was MSL / AGL so when given an altimeter setting from the tower, I set that and read my altitude MSL. Never got any Q's

 

We're on different continents so some variation in how things are done are to be expected, but "no Q's"? The QNH/QFE pretty much is the "altimeter setting". When I get my TO clearance the TWR will include a line stating what the qurrent QNH is, which I include in my readback. I just rotate the dial on the altimeter to display the QNH I was given et voila. (Or, if given QFE, which happens when dealing with the non-commercial aerodromes, same principle applies - QFE gets reported while getting my approach/landing clearances, I rotate the dial to that number and I have my AGL.)

 

If you've never "got any q's" I think you'd end up confusing yourself a lot if attempting to get clearances over here. They'll just say "Que Enn Eitch One Oh Oh Niner point Two Five" (or whatever) and assume you know what they're talking about. :P

(You can get your selection of nautical and metric though, whichever floats your boat. They're used to juggling planes with some on feet and knots and others on meters and km/h.)

 

QFE and QNH are arbitrary Q codes rather than abbreviations, but the mnemonics "Nautical Height" (for QNH) and "Field Elevation" (for QFE) are often used by pilots to distinguish them.

 

Average sea-level pressure is 101.325 kPa (1013.25 mbar, or hPa) or 29.921 inches of mercury (inHg) or 760 millimeters (mmHg). In aviation weather reports (METAR), QNH is transmitted around the world in millibars or hectopascals (1 millibar = 1 hectopascal), except in the United States, Canada, and Colombia where it is reported in inches (to two decimal places) of mercury. (The United States and Canada also report sea level pressure SLP, which is reduced to sea level by a different method, in the remarks section, not an internationally transmitted part of the code, in hectopascals or millibars.

 

...you guys always have to be so special. :P

 

On the note of conversions though:

http://www.hochwarth.com/misc/AviationCalculator.html

That one has a lot of nice little calcs that can be useful.

[as179mike]

same here. I went to flight school in New Jersey back in 1998 and got my PPL in 1999 and the only thing I was taught was MSL / AGL so when given an altimeter setting from the tower, I set that and read my altitude MSL. Never got any Q's

 

Thanks for coming to my rescue - I was starting to feel like an inferior pilot :helpsmilie:

 

I started mine in 1996 but had to take some time off and then finished up in 2001. I wasn't that far from you. I flew out of kgai in Montgomery county MD.

 

I think you're right ethereal, it must be different continents. We'll get the altimeter setting from the tower or from the weather recording and we set it on startup. I've always used msl or QNH and never zeroed the altimeter to the field elevation. Now this is all in a 172 ( from the 1970's no less) so it isn't the most hi-tech airframe out there. I have been given barometric pressure from ATC and the tower but it's always MSL (at least in my case as a VFR pilot).

Edited June 9, 2011 by as179mike
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[EtherealN]

Wow, I just checked one out, and yup - no Q-code on north american METAR, just that SLP. Crazy people. :P

[BlueRidgeDx]

In the US, everyone uses QNH; we just don't call it that. We simply say "altimeter". As in, "Altimeter Three Zero One Eight".

 

There's no reason to say the words "QNH", because there's no alternative standard in use; no one uses QFE.

[as179mike]

Wow, I just checked one out, and yup - no Q-code on north american METAR, just that SLP. Crazy people. :P

 

 

Haha - What else would you expect from us? We also still use imperial units for measurements :doh:

[EtherealN]

There's no reason to say the words "QNH", because there's no alternative standard in use; no one uses QFE.

 

Thanks, and yeah - makes sense. Sort of handicaps you for flights elsewhere, but I assume you have to fly quite some distance to find a place where it begins to matter.

 

(We had a similar "handicap" until recently here though - there were no english language proficiency tests for the issue of a radio license. With international borders with language switches a lot easier to find here in europe that's a pretty severe handicap and nowadays english language proficiency is a requirement even for a domestic license. Myself I "flew" Sierra Echo Whiskey Tango Foxtrot for my examination. The ATC guy didn't even chuckle though. :( )

Edited June 9, 2011 by EtherealN

[Shaman]

In the US, everyone uses QNH; we just don't call it that. We simply say "altimeter". As in, "Altimeter Three Zero One Eight".

 

There's no reason to say the words "QNH", because there's no alternative standard in use; no one uses QFE.

 

In Poland entire civilian aviation uses QNH or Flight Levels, however in military aviation all aircrafts inside MATZ airspace (military airport traffic zone) are separated using local QFE.

 

Because I was having my flights both inside MATZ and outside, I had experienced both worlds.

[redtail]

glad to see I didn't get inferior flight lessons :) It's just a matter of location and standards. Over here, we get the "altimeter" and that's what we set. Like others stated, I've never been tought to zero the altimeter only to use the field elevation in the rare chance the local altimeter setting is unavailable.

[Shanuck]

I don't know if anyone posted this or not, but here is an online easy calculator..just enter QFE and altitude of the airport 


https://www.hochwarth.com/misc/AviationCalculator.html#PressureAltitude

[ASAP]

Again, QFE is not used by the Air Force, or our NATO allies air forces. If you need to know how high you are above the ground look at your radar altimeter.