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Originally Posted by Rat 5
Perhaps they have an airfield brief covering that topic?
I didn't think EK has cadets Are EK F/O's encouraged to speak up? |
From another forum I follow:
Heard about this a few days ago. they were about to join the localiser when they implemented a missed approach just under 1000ft ALT (i.e. above mean sea level, how "height" is measured in the majority of the world), the elevation (height above sea leavel) of Moscow DME is approx 550ft, i.e. they were <500ft (approx 165m) above the airfield, hills/buildings could easily make up the difference at 8nm out from the threshold. Apparently both pilots were immediately grounded and not even permitted to operate back to DXB and are presumed to be fired shortly. They operated another failed approach, my source thinks they only then understood the problem, before a third successful approach. The problem: Russia uses the metric system in aviation. While I, and most of the "rational" world are proponent of the metric system, the aviation world has always used nautical miles, knots and feet. I also think that this should stay this way and be the standard method used. Unfortunately two major aviation regions, Russia and China, choose to differ. The problem with Russia, since an Airbus has a button to switch altitude to meters, is that ATC don't provide instructions with altitude in meters (again, altitude = height above SEA LEVEL - also known as QNH), ATC in Russia provide instructions in QFE - meters above AERODROME. Part of the standard approach procedure at DME, when provided joining instructions to the localizer (a radio beam from the runway that indicates the extended centreline and is used by the aircraft in lateral navigation to line up with the runway) is to descend to 600 meters (!!!) Now unfortunately the A380 doesn't have an automated system in place to implement this instruction, so pilots have conversion tables where they must look this up. Given the descent pattern of the subject aircraft it is plausible that the pilots simply input 600ft into their aircraft, when the correct reading would be 550ft+600m = approx 765m = approx 2200ft. From what I've been told they only realised the issue and implement the missed approach when they received an alert from the GPWS (ground proximity warning system). The scary part: The radar altimeter which provides the height (height = distance to ground) callouts during final approach (1000 above, 500 above, 100 above etc) beings way above what they were at, so they would've heard 2 or 3 height callouts already, and their assigned altitude (if 600m QFE) would've been above even the first such callout. Very scary stuff indeed, a 500 person A380 buried in the Moscow suburbs. |
Discontinue use of QFE (and demand Russia does likewise).
Discontinue use of pressure altimeters (and thereby eliminate setting errors) except as backup to GPS altimeters. Discontinue references to feet and metres in altimetry in favour of 'flight levels' throughout. So an airliner cruising at FL330 has 33,000 indicated on its altimeters (as at present). A pilot flying circuits in his Cub or Cessna 152 will report his flight level (not altitude) as (for example) 14 (or 014). |
As one who loved QFE, all I can say to that, is EEEEEEERRRRG!:uhoh:
(and demand Russia does likewise.). Oh, and as one who called for QNH in Texas and was met with a silence never before heard on USofA airwaves, I know that we all need to be using the same terms as well as rulers. As an oldie, I can't imagine going to metres for height but if the whole world made the change it would make a lot of sense. Though like driving on the right in the UK, I'd hate to be the one responsible for all the initial carnage. |
Originally Posted by Discorde
(Post 9901434)
Discontinue use of QFE (and demand Russia does likewise).
Discontinue use of pressure altimeters (and thereby eliminate setting errors) except as backup to GPS altimeters. Discontinue references to feet and metres in altimetry in favour of 'flight levels' throughout. So an airliner cruising at FL330 has 33,000 indicated on its altimeters (as at present). A pilot flying circuits in his Cub or Cessna 152 will report his flight level (not altitude) as (for example) 14 (or 014). |
There is no "auto initiated go around"
Originally Posted by sleeper
(Post 9896509)
Never heard of "auto initiated" go-arounds. I am not familiar with airbus, but on Boeings there are no auto initiated go-arounds. It can be done on autopilit, but the initiation is done by the pilot.
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Again, operating on QNH in an QFE environment is an error waiting to happen, especially when you are fatigued, hard to understand ATC, don't frequent a location often, etc.
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I've operated for years in & out of Russia and it's always been Flight Levels given in Metres, and altitudes (actually, heights) referenced to QFE and also given in Metres.
The navigation charts carried onboard typically contain altitude / height conversion tables i.e. to quickly allow one to ascertain the conversion between metric and imperial. Also, on Lido approach charts (which is what EK & FZ use) they provide the arithmetic correction (i.e. how many Mb's are needed) to convert the QFE (provided by Russian ATC) into QNH for that specific airport (and which is what you set on your Altimeter, i.e. QNH). Inside your aeroplane you're flying the whole thing as normal, i.e. with reference to QNH and feet. I myself would make this a risk assessment / risk reduction 'briefing item' and make sure that we both fully understand how to use the conversion tables. Using the chart below as an example, it would (or should) go something like this: ATC: "EK388 you're cleared descend 900m QFE" Have already worked out the relevant QNH (from the ATC provided QFE) and set it on your altimeter, you would then refer to the conversion table for this airport, find out where it says 900m QFE and look across to the left side of the table to find the equivalent number of feet QNH... in this instance that'd be 3580'... and that's what you then set (or as close as you can get to it) in the MCP Altitude Window... you both check & confirm it... and away you go (and, if there's doubt, you confirm the clearance with ATC before you do it).It's not exactly f'ing rocket science and only gets slightly more burdensome when it's seriously cold (what with 'cold temperature corrections', albeit - in a radar environment - ATC are supposed to take care of that aspect for you). The following chart shows the sort of conversion table that is commonly used. http://code7700.com/images/altimetry...metric_qfe.png |
Except the difference between QNH and STD could be huge. Your Cessna could be flying at 200 ft above ground in your scenario. ICAO resolution 23/2020: 'No non-Russian registered aircraft will operate within Russian airspace unless their crews are permitted to use absolute altimetry (derived from GPS signals or local sea level air pressure) at all levels. Altimeter scales will be graduated in Imperial feet but indications (divided by a factor of 100) will be referred to as 'flight levels' at all levels.' |
Originally Posted by Old King Coal
(Post 9901724)
I've operated for years in & out of Russia and it's always been Flight Levels given in Metres, and altitudes (actually, heights) referenced to QFE and also given in Metres.
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Just a few thoughts:
As the chart says, you can request QNH then use the table on the chart to convert the cleared metric level into feet. For some companies this is SOP in Russia. GPS Altitude is not a reliable source and prone to DOP and Errors. Another factor could be, that Russia is not WGS84 compliant as they use a different Geoid for their GLONASS System. |
Airbubba:
And in RVSM airspace, Russia uses flight levels in feet |
Originally Posted by caiozink
(Post 9901516)
Airbus normal airplanes, flown by pilots too ! Go arounds are initiated by them....no such thing as auto go around !
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1 Attachment(s)
Originally Posted by Propellerpilot
(Post 9901815)
Just a few thoughts:
Another factor could be, that Russia is not WGS84 compliant as they use a different Geoid for their GLONASS System. |
Originally Posted by atakacs
(Post 9901860)
I'm actually quite happy to read that (although the initial wording was somehow implying differently) but out of curiosity what happens if the autoland detects some abnormally? Just an ECAM message and revert to manual flight?
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No it ain't rocket science but it is an extra two steps to a critical clearance (descent vector) to normal to be done a bunch of times on the arrival. Fair enough, happens all day every day but it is most certainly 2 big holes in the cheese waiting to add up to another distraction/busy environment/crew fatigue etc
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Couldn't agree more. Reams and reams of conservative rules and regulations in other areas and this is allowed in this day and age. Crazy, in my opinion.
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presumed to be fired shortly https://livingsafelywithhumanerror.c...-of-expertise/ https://livingsafelywithhumanerror.c...ion-accidents/ Reminded of a story about a junior exec who cost the company some heaps of money on a contract through some ill thought out decision. A toady sucking up to the boss remarked, "well, that's him for the sack". Boss replied, "what? after all the money I just spent on his education?". |
Originally Posted by maggot
(Post 9901949)
a bunch of times on the arrival
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GPS altitude : will not work below 3000 ft because the earth is not a perfect circle . Your C152 will find itself 1000ft below the ground in some places..
As said before WGS84 is an North American reference point made artificially to ensure positive altitude above its continent . Will not work in other parts of the world. QFE. meters and Russians : This is not the cause of this incident . Tens of thousands of western aircraft fly every year since decades in this mixed environment without problems. I would say lack of proper training is . This is the common denominator of many incidents / accidents we see today. Add fatigue to that , plus fast airline expansion introducing new routes/ airports ,and not visiting them often and there you go. Fixing the training issue would also far easier than changing Units of measurement on a global scale..:rolleyes: |
As said before WGS84 is an North American reference point made artificially to ensure positive altitude above its continent . Will not work in other parts of the world. |
Originally Posted by ATC Watcher
QFE. meters and Russians : This is not the cause of this incident
I would say lack of proper training is Add fatigue to that fast airline expansion introducing new routes/ airports The issue I submit to you ATC Watcher is not having the time to recharge the batteries between trips... ULR over the pole to LAX one day and a few days later doing a DXB/BKK/SYD trip for example! |
India 4 2 :
Nonsense! There is a reason why it is called the World Geodetic System. White Knight : I am not talking about EK in particular, just looking at incident/accident reports . The recent TK A330 in KTM, or the SFO 777 are good examples to start with. I think you perhaps mix up causes and contributing factors. For instance fog or Cb are not causes . Like QNH/QFE or m/feet conversion. Contributing factors maybe ( as we do not yet know yet what happened here , just Internet speculation ) but not causes. That was my point. |
WK and his reference to fatigue, speaks very true words.
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GPS altitude : will not work below 3000 ft because the earth is not a perfect circle . Your C152 will find itself 1000ft below the ground in some places.. As said before WGS84 is an North American reference point made artificially to ensure positive altitude above its continent . Will not work in other parts of the world. The grid is based on UTM, with 60 zones. Each gridline is its own unique reference line, and is ultimately accurate. Zone 1 and 60, moving from West to East, and letters from South to North., and does not relate to the Prime Meridian, nor 85W. Max difference between geoid and ellipsoid is 105m. IF you have a GPS on the aircraft, or wherever, the system calcs the difference between the Geiod (MSL) and the Ellipsoid (GPS alt) by means of the lat/long and corrects, so you dont have to. It does not give you AGL, it gives you altitude based on MSL. |
Back-up (pressure) altimeters would have local sea level air pressure value sent to them automatically by data link (with a readout of this figure available for cross-checking against forecast values). In commercial aircraft a discrepancy between the GPS and pressure altimeter indications exceeding pre-determined limits would generate a crew alert. Development of this sort of kit is within the bounds of current technology.
The Cub pilot would be responsible for manually setting LSLAP on his or her old tech altimeter. |
As Underfire stated, WGS84 is a worldwide system adopted by ICAO around 1989.
In the early days of RNAV, but later than 1989, many countries were not WGS84 compliant. More and more complied as the years passed. Several years ago if I would select an airway or terminal procedure in a country that was not WGS84 compliant, I would get an advisory message "X Country not WGS84 Compliant." I believe most countries are WGS84 compliant in 2017. I tested Russia at UUDD with a current database. UUDD has several RNAV approaches. I did not receive a WGS84 noncompliance advisory alert for a UUDD RNAV IAP that I selected. As to China, Hong Kong has RNP AR procedures. So, at least that portion of China is WGS84 compliant. So is Tibet as it has a very sophisticated RNP AR approach procedure developed some years ago for China Airlines by Naverous. I selected ZUCK in China that has some ILS procedures with RNAV transitions and some without. I wasn't able to select the RNAV/ILS procedures. I'm not sure what that means. |
I can confirm that 'underfire' and 'aterpster' are right. Many years ago I was involved in updating an airline's charting and in work on GPS and Galileo compatibility.
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Then I stand corrected.
I was in an ICAO meeting in the early 1990's where all this was explained, the earth being a " potatoid" (I remember that term !) therefore every major State used a different reference point/system fitting their Country or continent surface. Since GPS was going to be used worldwide , the USA GPS standard was chosen to the the ICAO standard for their GNSS. ( The then USSR fiercely opposed this , but since they dissolved around that time , they lost the argument ) To be fair in those days we were looking at 2D ( Lat/long positions maps, etc..) , not altitude at all. |
ATC WATCHER,
It was an interesting time when WGS 84 was being introduced and we found that all the individual country's surveys did not quite connect - sometimes by a few metres and sometimes by many miles! |
The confusion probably stems from the fact that, for all intents and purposes, WGS84 and NAD83 (North American Datum 1983) are virtually the same over North America and evolve together. That is why the US did not care if it was WGS84.
Now lets start talking vertical datum, ellipsoids and geoids, h and H, that is hours of fun! |
aa,
A man after my own heart! Hours of fun indeed, trying to explain the difference between h and H to people who have never heard the term ‘geoid’ and who think lat/long values can never change. underfire, A small clarification. Universal Transverse Mercator (UTM) is a widely-used and very useful map projection, but it has nothing to do with the definition of WGS84. Confusion can arise because the projection formulae use the parameters of a spheroid to convert lat/longs to eastings/northings. The spheroid used is usually the same spheroid that is specified in the geodetic datum that was used to calculate the lat/longs, but it doesn’t have to be. As a consequence, a properly labeled map will have not only the geodetic datum parameters, but also the parameters used for the projection, including the spheroid. Rather than expand at length, I offer the following Wiki links, for further reading: https://en.m.wikipedia.org/wiki/World_Geodetic_System https://en.m.wikipedia.org/wiki/North_American_Datum https://en.m.wikipedia.org/wiki/Univ...rdinate_system On a final note, the US DOD were the initiators of the work that led finally to WGS84 and they did this because they needed a world-wide, earth-centred datum, to help in targeting ICBMs. |
Crazy enough, when the Collins FMS-800 was installed in the C-5, we could select the datum to be used with WGS-84 as the default. If wanted the Argentine 1926, if was there and everything shifted. Not sure who thought that up.
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It was an interesting time when WGS 84 was being introduced and we found that all the individual country's surveys did not quite connect - sometimes by a few metres and sometimes by many miles |
Originally Posted by India Four Two
(Post 9903838)
On a final note, the US DOD were the initiators of the work that led finally to WGS84 and they did this because they needed a world-wide, earth-centred datum, to help in targeting ICBMs. Then remember selective availability, which Bill Clinton finally turned off. |
It's likely as you read this that there are several aircraft around the world flying with mis-set or mis-read altimeters. Some pilots will have omitted to change from QNH to standard when climbing through transition, others the opposite during descent. Some will be reading altitude on QFE and others height on QNH, which may result in level busts or airspace violations. Some will have incorrectly converted feet to metres or vice versa.
In Europe the problem is compounded by low Transition Altitudes. Every time a deep low pressure weather system crosses the UK a Notam has to be issued to remind pilots to be vigilant in setting standard when climbing through TA to avoid traffic conflicts. Of course, in such weather turbulence and wind shear are more likely to be encountered, distracting crews from essential tasks (such as resetting altimeters) at this critical time. The consequences of altimeter mis-sets or mis-reads will usually be limited to red faces when the error is discovered. But now and again . . . |
Originally Posted by Discorde
(Post 9904779)
In Europe the problem is compounded by low Transition Altitudes.
Why put the transition altitude/level down low where things are busy and traffic is most congested? :confused: Fortunately QFE, like ADF holding, is almost extinct at large international airports in my experience. :ok: |
As to China, Hong Kong has RNP AR procedures. So, at least that portion of China is WGS84 compliant. So is Tibet as it has a very sophisticated RNP AR approach procedure developed some years ago for China Airlines by Naverous. Yes India24, the UTM was comment rushed, I was thinking about the current project I am working on where the land based mapping is UTM. WGS 84 is based on the prime meridian. A straight path across the surface is one thing to calculate, but a curve path on the surface is quite the other...the regulatory agencies were using the Helmert Formula, but that is not accurate enough for curves, so we use Vincenty's Formula which is far better. In the end, the aircraft system understands WGS 84... From Jeppeson. WGS84 Compliance worldwide... https://i.imgur.com/GpE3qhw.jpg http://ww1.jeppesen.com/company/publications/wgs-84.jsp |
From WK--
The issue I submit to you ATC Watcher is not having the time to recharge the batteries between trips... ULR over the pole to LAX one day and a few days later doing a DXB/BKK/SYD trip for example! However, the point about time zone change and subsequent effects is the one that strikes me . I have always wondered why it was not possible for a roster to avoid this mix of Far West , followed by Far East . I always felt it should be a case of one or the other, with a North/South rotation filling in the rest of the month , (although in this case a Moscow trip would be following that philosophy ) . But then, bidding software perhaps makes that wish "mission impossible" . I don't know , but I do have a lot of sympathy for the rostering departments ; an unenviable job , as you could never satisfy everybody. , especially with the top floor guys coming in at short notice to make their own requests for favorite destinations ( usually combined with favorite seasonal weather---westbound in summer, eastbound in winter,---" no typhoons approaching; no Cat 3 approaches, please...). In a previous gentlemanly life, (744 cargo) , we had a great route structure; set off eastbound and arrived back at base 2 weeks later, having traveled round the world in one direction (with multi day layovers), followed by a week off to "recover". 60 hours a month, if you were lucky. Sadly, it seems those days are long gone..... |
Rather long missive published to all Pilots by EK Training Management. Reference all the recent accidents incidents etc. Shake up in training and including introducing regular unannounced spot checks on route sectors by Route Check Capts.
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