Landing with QFE - how to set the press. controller?
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From: near an airport
Landing with QFE - how to set the press. controller?
You are landing with a QFE altimeter setting, would you set the pressurization controller to 0ft? Or would this depend on the aircraft type?
Joined: Jun 2006
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From: Canada
On a normal aircraft no change, field elevation plus what ever fudge the AOM calls for {ie field elevation plus some fixed figure or corection for density alt, depends on AC type} But on some all magic aircraft the presure controller gets its info from the altimeter setting on the pilots display, which is a good reason not to use QFE {I only know of one aircraft like this and I belive they are all now modified} Other magic aircraft know where you are landing and dont care if you are using QFE, but again, why use QFE?
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From: Canada
Dvv, I know that, flew there many times {not counting the Cold War} The question remains Why use it? the top 300 feet of hills and mountains around the world are covered with bent metal thanks to QFE. {PS, I wonder how many even know the Q Code these days?}
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From: KIAD east downwind
clunckdriver, I guess it's because how it's been in Russia forever. And they hadn't had any pressure to use the western standartization on QNH (and foot altitudes and flight levels) until rather recently.
P.S.
Lots of places don't use fixed 18000'/FL180 for altimeter setting change, but I gather you know that already
P.S.
Lots of places don't use fixed 18000'/FL180 for altimeter setting change, but I gather you know that already
Last edited by dvv; 21st July 2010 at 00:00.
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From: Canada
Dvv, untill they programed the "wake you dumb twit" reminder to change to 1013mb/ 29.92inch on climb out on the 767 I lost track of how many times I was late on this, these days however in my little 421 it aint a problem, rarley get high enough to change, also never need QFE.Regards Clunck.
Joined: Dec 2002
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From: Where the Quaboag River flows, USA
Clunckdriver
I'd like to see some stats or accident reports blaming QFE for "the top 300 feet of hills and mountains around the world are covered with bent metal thanks to QFE"? The only one I can name is AA at KBDL in the early '90s where the tower abandoned ship due to high winds, the crew didn't have a correct QNH to convert to QNH and hit the trees on Avon Mountain. Other than that, I cannot remember an airline accident blamed on QFE. In fact, EA and AA used QFE precisely because it give pilots a better reference as to their height above the runway. Needless to say, I like it and, once accustomed to it at EA, saw it advantages.
Where QFE is the standard means of altimetry, why go against it. The conversions can cause more problems than just comforming.
GF
I'd like to see some stats or accident reports blaming QFE for "the top 300 feet of hills and mountains around the world are covered with bent metal thanks to QFE"? The only one I can name is AA at KBDL in the early '90s where the tower abandoned ship due to high winds, the crew didn't have a correct QNH to convert to QNH and hit the trees on Avon Mountain. Other than that, I cannot remember an airline accident blamed on QFE. In fact, EA and AA used QFE precisely because it give pilots a better reference as to their height above the runway. Needless to say, I like it and, once accustomed to it at EA, saw it advantages.
Where QFE is the standard means of altimetry, why go against it. The conversions can cause more problems than just comforming.
GF
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From: UK
To answer the question from the OP, I don't know about other aircraft but from the 737 FCOM, the last item for QFE Operation supp procedures is:
Landing altitude indicator ............ Set at zero
And whilst we're on the subject, can someone please explain to me the reason for this:
Use only raw data for navigation.
I can understand why they say don't use VNAV, but why not LNAV?
Landing altitude indicator ............ Set at zero
Note:
Do not use LNAV or VNAV below transition altitude/level.
Altitudes in the navigation data base are not referenced to QFE.
Altitudes in the navigation data base are not referenced to QFE.
Use only raw data for navigation.
Joined: Mar 2001
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From: I wouldn't know.
Our 737 FCOM has the following restriction in the chapter limitations:
"QFE Operation
The QFE operation is prohibited on the main aircraft altitude system due to the fact that EGPWS data are based on QNH." The supplementary procedure just contains a note that points to that limitation.
Not a problem to fly into QFE-Areas if you have a chart supplier that is up to scratch. LIDO makes a pretty good impression there, but Jepp was usable as well, only EAG was, as in all regards, really below par.
"QFE Operation
The QFE operation is prohibited on the main aircraft altitude system due to the fact that EGPWS data are based on QNH." The supplementary procedure just contains a note that points to that limitation.
Not a problem to fly into QFE-Areas if you have a chart supplier that is up to scratch. LIDO makes a pretty good impression there, but Jepp was usable as well, only EAG was, as in all regards, really below par.
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From: on.tour
QFE
..we always set 0 ft in CRJ2/CL850
no big deal if you forget a apts with low elevation, but expect a pressure bump upon landing at eg Almaty, if you don´t set 0ft.
@ drivers handbook:
asked exactly this question at the cl30 rating, it took the FS guys half a day to find the correct answer (oft)
fly safe
welle
no big deal if you forget a apts with low elevation, but expect a pressure bump upon landing at eg Almaty, if you don´t set 0ft.
@ drivers handbook:
asked exactly this question at the cl30 rating, it took the FS guys half a day to find the correct answer (oft)
fly safe
welle
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From: Canada
Galaxy, I started to list them but found an easier way, if you simply Google "Aircraft crashes due to QFE" it should answer your question, if not PM me. Buried in the data is a very interesting clip from Flight Magazine 1969/1355, a case of "Whats that Mountain Goat doing up here in the clouds?" Regards, Clunck.
Per Ardua ad Astraeus
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From: UK
Clunk - QFE ops require an extra amount of airmanship/care which is probably lacking today. It is just an awareness of where you are and where the 'hard stuff' is that is required, and if you (correctly) leave QNH on the standby........................job done?
Not everyone has the luxury of operating on QNH everywhere.
Not everyone has the luxury of operating on QNH everywhere.
Joined: Nov 2001
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From: on.tour
why..
why use QFE?
Flyin´in and out of moscow and russia everyday, using QFE is the easiest and best option to do.
1st: try to request local QNH from UUWW/Vnukowo approach controller on a buy day...., have fun - have even more fun and request an Altitude not Height..
2nd: try to find QFE tables for some inner-russian apts, where there are not even jepp. plates available and you have to use a navigator
3rd: use QFE to avoid confusion: all acfts and controllers around use QFE and Meters..., so if you are instructed to descend 400m and cleared approach on a 90° heading - i think it is not the correct time to check the approach plate head down and find the correct value out of three colums and recheck with the PM. just set 400m and fly the aircraft.
my 3 cents
welle
Flyin´in and out of moscow and russia everyday, using QFE is the easiest and best option to do.
1st: try to request local QNH from UUWW/Vnukowo approach controller on a buy day...., have fun - have even more fun and request an Altitude not Height..
2nd: try to find QFE tables for some inner-russian apts, where there are not even jepp. plates available and you have to use a navigator
3rd: use QFE to avoid confusion: all acfts and controllers around use QFE and Meters..., so if you are instructed to descend 400m and cleared approach on a 90° heading - i think it is not the correct time to check the approach plate head down and find the correct value out of three colums and recheck with the PM. just set 400m and fly the aircraft.
my 3 cents
welle
Joined: Oct 2006
Posts: 658
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From: Ankh Morpork, DW
BOAC wrote:
Okay, no he didn't write that last part. . .
Break break.
I do QNH into QFE fields several times a month. It truly is a pain in the butt to get a clearance, read back the clearance, look at a table, set one altitude in feet and say a totally different number in meters.
QFE ops require an extra amount of airmanship/care which is probably lacking today. Back in my day, we had to hand prop our turbojets! And we also had to distill our own Jetfuel. Jet-D we called it - because we had to go out and kill the Dinosaurs that became the oil that became the fuel.
Okay, no he didn't write that last part. . .
Break break.
I do QNH into QFE fields several times a month. It truly is a pain in the butt to get a clearance, read back the clearance, look at a table, set one altitude in feet and say a totally different number in meters.
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From: no more moscow
correct setting of pressure controller
After reading the first post, most of the following posts seems to be a complete off the target...
... so I'm not getting into QFE vs QNH ops discussions in a QFE environment...
As the answer to the question is maybe type-specific, the easy way to check the correct setting of the pressure controller is as follows:
- after landing (when normally all outflow valves have opened), the cabin altimeter shows a certain value.
- if this value is zero, (like the main altimeters when set to QFE) then the pressure controller should have been set to zero.
- if that value shows approx. the elevation in ft, the pressure controller should have been set to elevation.
While it does not really help on the first landing, it helps at least for all the following flights on that type.
Nice flights
MJ
... so I'm not getting into QFE vs QNH ops discussions in a QFE environment...
As the answer to the question is maybe type-specific, the easy way to check the correct setting of the pressure controller is as follows:
- after landing (when normally all outflow valves have opened), the cabin altimeter shows a certain value.
- if this value is zero, (like the main altimeters when set to QFE) then the pressure controller should have been set to zero.
- if that value shows approx. the elevation in ft, the pressure controller should have been set to elevation.
While it does not really help on the first landing, it helps at least for all the following flights on that type.
Nice flights
MJ
