Altimeter confusion...

Obviously you don't fly commercially. Approach profile altitudes are based on QFE. Try again.

I don't fly commercially. I do however control commercially and I have not once used or given out QFE. I think you are confused by the terminology, by definition altitude is height above MSL hence QNH. QFE is never Altitude.

QNH = Altitude

QFE = Height

SPS = Flight Level

The procedure you linked does indeed reference AAL (Above Aerodrome Level). However they are still climbing to a Missed Approach "Altitude" hence will have QNH set. As pointed out above they will use either a radar-alt to provide the AAL references or add field elevation onto the referenced heights to convert to Altitude. No requirement for QFE there at all.

As for approach procedures and missed approach procedures they are all on the approach plate (where everything is flown with reference to QNH).

e.g.

Edinburgh 06 ILS

Humberside 02 NDB

The vast majority of GA airfields lay outside controlled airspace, so that's a poor example.

The vast majority of GA airfields don't have ATC so they can do what they like. Fly VFR in to any commercial airport or even try and transit their zone and you will be given a clearance at an altitude, not a height. Hence QNH.

The vast majority of GA airfields don't have ATC so they can do what they like. Fly VFR in to any commercial airport or even try and transit their zone and you will be given a clearance at an altitude, not a height. Hence QNH.

Simply not true. Biggin Hill, Lydd and Southend are all busy commercial airfields that will issue QFE to arriving traffic and traffic in the VFR circuit. Transiting aircraft will remain on QNH, but that's because they won't be entering the circuit.

Simply not true. Biggin Hill, Lydd and Southend are all busy commercial airfields that will issue QFE to arriving traffic and traffic in the VFR circuit. Transiting aircraft will remain on QNH, but that's because they won't be entering the circuit.

Your definition of "Busy Commercial Airfield" obviously differs from mine. Try getting a VFR transit or do circuits using QFE at Glasgow, Aberdeen, Edinburgh, Manchester, Birmingham, Cardiff, Southampton, Luton, Gatwick or Stansted and see how far you get.

The fact remains that, in the UK, with the exception of the RAF and VFR GA doing circuits at largely GA airfields, QFE is not used. Like I said, I've been a controller for almost 10 years and never used it once.

I don't fly commercially. I do however control commercially and I have not once used or given out QFE. I think you are confused by the terminology, by definition altitude is height above MSL hence QNH. QFE is never Altitude.

 

QNH = Altitude

QFE = Height

SPS = Flight Level

 

The procedure you linked does indeed reference AAL (Above Aerodrome Level). However they are still climbing to a Missed Approach "Altitude" hence will have QNH set. As pointed out above they will use either a radar-alt to provide the AAL references or add field elevation onto the referenced heights to convert to Altitude. No requirement for QFE there at all.

 

As for approach procedures and missed approach procedures they are all on the approach plate (where everything is flown with reference to QNH).

 

e.g.

 

Edinburgh 06 ILS

 

Humberside 02 NDB

OMG! People, I never mentioned Approach Plate. Re-read my whole conversation.

Now I already never liked flying as a passenger in commercial planes because I know they're not really flown, autopilot flies them. And it's all about doing it as cheaply as possible. And also the training has to be as cheap as possible... I oftne read crash investigation reports and it's amazing how often it's due to pilots making unacceptable errors, like forgetting how to fly the aircraft. This will only happen more and more often in the future I'm afraid, since airliners are getting more and more automated...

 

I like how Eagle7907 talked about setting QFE at KASE, Aspen, Colorado. That airfield has an elevation 7838ft. Let's say we're having a standard day, you're on the threshold and want to set QFE. You start turning your altimeter dial. And you're turning. And turning. And turning. Guess what, your altimeter probably stopped turning at 28.00inHg, because that's the lowest pressure range for most altimeters. To set QFE at KASE, you'd need to set your altimeter a lot lower than that, at around 26.56. You can't do that... And an airline asking it's pilots to use QFE basicly shows that the airline itself doesn't even think highly of their own pilots if you ask me.

 

The only advantage of QFE is that you will have nice round numbers on your altimeter (at most airports). This will make it easier for the pilot, because for some reason some pilots might have a hard time reading numbers that aren't round... So it's a simplification. The disadvantages are that it's an incorrect setting, on purpose. What the altimeter shows is erroneous. Another disadvantage: You can't read your altitude anymore. Another disadvantage, other pilots are probably doing it right and are using QNH. Imagine them flying around the one nutjob who's using QFE and hardly has a clue how high he's flying or where the other aircraft are. Conclusion: It's very bad practice to use QFE and in fact, it's unsafe.

 

It's kinda like when you're driving a car and the speed limit is 55mph. You decide to drive 60mph because it's easier to see on your speedometer and it's a nice round number

Actually, it's not as unsafe as you think it is, on a commercial airliner. We have three SEPARATE altimeters, also two separate transponders. The pilot flying can keep his altimeter to QNH while the pilot monitoring can set it to QFE. The transponder is slaved to the corresponding altimeter. So the pilot doing the approach, flying the airplane, maintaining separation, etc, will be using correct QNH and the other just knows how high they are from the runway. Even the autopilot can be slaved to either side. Thus, you will be at the correct altitude at all times when set up correctly.

FYI the third one is the standby altimeter. Not as accurate as the other two. Used when all the generators go out.

One person asked a question, I answered. I'm being told I'm wrong, when I know AA dispatchers have the info. People, I'm telling you, it IS used, it can be used. End of line.

Approach plate, approach profile. Doesn't matter. What you said about QFE was still incorrect. Just admit that you made a mistake and let's move on.

Dude.... Whatever, go fly your precious game in whatever reality you want. I'll go fly my real plane using QFE if I want. Just don't call me a liar because you want to believe you're smarter than an airline pilot who has over 5,000 hours logged and been doing it for over 7 years.

It is used, it can be used. The end.

Your definition of "Busy Commercial Airfield" obviously differs from mine.

What has anyone's definition of busy got to do with it? You stated that ATC wouldn't have traffic flying on differing altimeter settings and that "QFE may be used at uncontrolled GA aerodromes but it certainly has no place in the commercial world." I've provided examples that show your statement is simply not correct.

What has anyone's definition of busy got to do with it? You stated that ATC wouldn't have traffic flying on differing altimeter settings and that "QFE may be used at uncontrolled GA aerodromes but it certainly has no place in the commercial world." I've provided examples that show your statement is simply not correct.

It's obviously a real vs gamer thing going on. I guess if you play a game, you are automatically an expert. They will not/refuse to understand. Let them be in whatever reality they want and we can go do the real thing.

It's obviously a real vs gamer thing going on. I guess if you play a game, you are automatically an expert. They will not/refuse to understand. Let them be in whatever reality they want and we can go do the real thing.

It would appear so. I've even had rep taken off me by someone who claims that I'm an "Amateuristic pretend-pilot", despite the fact that the only reason I know he's full of it is because I've got a pilots license and routinely operate in conjunction with ATC in a manner he says doesn't happen :lol:

Idiots.

It's a profile, man. In my American Eagle Airlines manual, that was certified by the FAA, it's tabulated "profiles". And there is a profile that almost looks exactly like that for that exact procedure. A go-around/missed approach for the pilot flying.

 

Like you said before, as a shortcut, it can be used. Or just do the mental math. 1,500MSL-500FE = 1,000 Above FE or 1,000' QFE

 

Edit: the pilot monitoring will have the more items related to QFE.

Procedure. I have an MA in English. Incorrect word usage frequently confuses me.

It's obvious that you have had some terminology confused, almost everyone in this thread has spotted that. But since you're such an experienced commercial pilot your pride won't let you admit it.

Altimeter confusion...

Procedure. I have an MA in English. Incorrect word usage frequently confuses me.

 

It's obvious that you have had some terminology confused, almost everyone in this thread has spotted that. But since you're such an experienced commercial pilot your pride won't let you admit it.

The tabulated chapter of the American Eagle Airlines, Aircraft Operation Manual for the EMB-145 Volume 1 says"PROFILES". So you are telling me that a corporation of 10,000 people got it wrong. Yeah. Edit: which is certified by the FAA, so the government got it wrong, too?

Listen, you can argue with me and say I'm stupid or I don't know what I'm talking about, but now you're saying thousands of people got it wrong? You may think it's about pride, when it's about fact. Unless you are an FAA inspector and can explain to me why an error is okay, then fine. Until then enjoy your game.

Corporations of 10,000 people are just as fallible as one person. In fact, with 10,000 fallible people it makes the chances higher. But that's beside the point. As an IFR-rated pilot you should know that the terms "approach profile" can also refer to the profile view on an approach plate, so why didn't you clarify that you were talking about an aircraft-specific procedure from the start? This brings up another question, under what circumstances would an "approach profile" for a specific aircraft override the approach profile as indicated in the approach plates?

Every resource I can find indicates American Airlines stopped using QFE as company procedure some time between 1995 (Flight 1572 incident) and 2003. Since we have had so many posers on these forums I will remain suspicious until I see that EMB-145 AOM and some kind of current documentation indicating that QFE usage is still practiced by AAL today.

Yeah. Edit: which is certified by the FAA, so the government got it wrong, too?

Don't even get me started on how many things the American government has gotten wrong. This isn't a political discussion board anyway.

Again, you can continue to defend your mistakes in this thread simply by your word, or you can provide the proof I requested above.

What has anyone's definition of busy got to do with it? You stated that ATC wouldn't have traffic flying on differing altimeter settings and that "QFE may be used at uncontrolled GA aerodromes but it certainly has no place in the commercial world." I've provided examples that show your statement is simply not correct.

I concede that perhaps QFE is more extensively used than I thought. But the fact remains that it is not used at any large airports inside controlled airspace for VFR or IFR. I am basing this on my own experiences as a controller that has worked 5 different sectors during my career, 3 large commercial airports and 2 low level area sector, all with a good mix of GA, commercial and mil traffic. Not once have I been asked for QFE. Fact!

The main point I was trying to make in this thread was that I would find it very unlikely that a commercial operator (like AA) would use QFE for anything. The "procedure" or whatever he calls it that Eagle7907 linked to makes no reference to QFE at all. This Thread on pprune appears to confirm that AA did use QFE up until the 1990s but, according to that thread, has followed most other operators in banning the use of QFE.

I'm not sure what this "profile" thing that Eagle keeps bleating on about. At the end of the day the approach plate is the law, it tells you how you "must" fly the approach. End of discussion.

The other posts I have made in this thread were to correct obvious mistakes and misinformation...

Also since when did aircraft have 2 transponders? And why would any of them need to be slaved to the cockpit altimeters? Genuine question?

It's obviously a real vs gamer thing going on. I guess if you play a game, you are automatically an expert. They will not/refuse to understand. Let them be in whatever reality they want and we can go do the real thing.

Now now, no need to resort to insults. I never pretended to be an expert and I'm certainly not basing my opinions on a game.

Idiots

Nice to meet you too buddy :thumbup:

This Thread on pprune appears to confirm that AA did use QFE up until the 1990s but, according to that thread, has followed most other operators in banning the use of QFE.

This NTSB report on AA Flight 1572 says that company policy was to set both captain's and first officer's primary altimeters to QFE and the standby altimeter to QNH (which doesn't match the procedure Eagle was talking about when he said that only the first-officer sets his altimeter to QFE). There's also a scan of a 1995 AA flight manual detailing the needlessly complex procedure.

Also in this book it says that AA stopped using QFE as company procedure "for various reasons" shortly after the Flight 1572 incident in 1995. I reached my "viewing limit" on that site so I can't provide an exact page number for that reference, but it's in the footnotes.

I concede that perhaps QFE is more extensively used than I thought. But the fact remains that it is not used at any large airports inside controlled airspace for VFR or IFR. I am basing this on my own experiences as a controller that has worked 5 different sectors during my career, 3 large commercial airports and 2 low level area sector, all with a good mix of GA, commercial and mil traffic. Not once have I been asked for QFE. Fact!

I've only flown in the SE UK but it's always QFE for arrival/circuit work. From what I understand of ATC, the training you get is pretty specific to your sector, and if you don't get much GA I'm not surprised you've not used it. I've also transited Gatwick's airspace; I can understand why you wouldn't use it for an airport like that either. It's crazy busy!

Also since when did aircraft have 2 transponders? And why would any of them need to be slaved to the cockpit altimeters? Genuine question?

More sophisticated aircraft have two transponders, but a single panel, so it's not obvious. See this 737 panel:

Bottom right you select which one you want to use. Above it you can select the air data computer source you want it to use (either captain's of fo's). The altitude reported by that air data computer will be what gets transmitted to your scope via mode c/s. I imagine if you fiddle with the baro knob on the altimeter, it'll change the reading transmitted to you, and hence Eagles comments about choosing which one's selected.

Nice to meet you too buddy :thumbup:

You've conceded, and that's something you don't see much on the 'net :thumbup:

Guys I said was I've seen the ACARS print out from dispatch sent to my aircraft. I didn't even know what it was for until the Captain said that was for AA flights. He said sometimes dispatchers will mistakenly send AA stuff to us. And this was 2 years ago. So explain that to me? I don't know what your source is, I don't know if it's reliable or not. I'm done with this debate. Unless you work for AA, pilot or dispatcher, who can explain why we get this information then I'll eat my words. Until then game on.

Idiots.

You don't wanna go there. That goes to all of you.

I know they say that if the wiser man always gives in, the moron will rule the world, but seriously, return to a factual discussion or just don't post here.

.Oh, and I also think you forget to mention you most probably have 4 or 5 altimeters, instead of only 3.

1 or 2 radio altimeters. Am I right?

Congratulations, you found Wikipedia. You're still clueless about aircraft operations.

And I fly GA, so one altimeter and no autopilot.

Actually, that information is in my head. Has been for years. It's kinda dangerous to say I'm clueless about aircraft operations if I apparently know more about it than you do, judging by at least this thread.

 

You could be just as wrong as you are about using the altimeter and how your transponder works...

Assumption is the mother of all **** ups, especially in aviation.

 

You know, you also could've replied in another way, like admitting you were wrong and thanking me for showing how it really works. What's wrong with that?

I know how mode c works. Airliners with ADS / mode s are not my specialty. I was hypothesizing based on Eagle's comments.

If you claim to knew anything about ops, why do you continue to insist that QFE is pointless/dangerous etc when it's used routinely?

As Grzly alludes to the reading we get from the transponder is based on 1013.2. Our radar processors then convert to altitude based on the QNH and where you are on the radar. It's obviously easier this way round as the transition altitude changes depending on where you are, and it also rules out pilot error in setting the subscale.

The reason I asked about the slaving is because I was always under the impression that the transponder in most modern airliners had it's own altimeter and encoder (but still fed from the same static source). Could the switch in your image perhaps be to switch between static sources as opposed to altimeters?

You've conceded, and that's something you don't see much on the 'net :thumbup:

I'm the first to admit when I'm wrong :)

Nice excuse. Too proud?

Stop trolling.

This is my last warning. This will either continue as a factual discussion or it will be shut down.