altimeter settings in USSR

[L'Argonauta]

Which altimeter setting do you use when approaching an ex USSR Airport?

I was landing in Astana, below TL we decided to set Qfe at 4 Dme we were established and perfect VMC daylight the Egpws started to sound "TOO LOW TERRAIN", we disreguarded the warning and landed normally.

I reported it to my Tr.PH and he said that he had tha same warning when using Qfe because the EGPWS system works with altimeter setting and suggested me to use Qnh...

When you approach and land in Astana the ATC provide you with Qfe ( Qnh only on request ) but their clearances are issued in HEIGHTs ( example "descent to height 800 Qfe 998") so if you decide to use Qnh you have to do the maths by yourself to get the ALTITUDE ( height plus elevation ) and it's quite hard as long as you have to convert from meters to feets!!

:zzz::zzz::zzz:

[PicMas]

Disengage the terrain warning when approaching on QFE

[Son of a Beech]

According to my humble upinion the GPWS Mode 4 (A/B) callout "to low terrain" is a result of to high speed at to low RAD ALT not BARO ALT.

explaned mode 4(A/B)

4A - Unsafe Terrain Clearance With Landing Gear Not Down
This is the terrain clearance mode with the gear retracted, is armed after take off upon climbing through 700 ft radio altitude. When this envelope is penetrated at less than 0.35 mach the aural alert TOO LOW, GEAR is sounded. When the envelope is penetrated at more than 0.35 mach, the aural alert TOO LOW TERRAIN is sounded and the upper boundary of the envelope is increased to 1000 ft rad alt. The message is repeated until the flight condition has been corrected.

4B - Unsafe Terrain Clearance With The Flaps Not In Landing Position
This mode provides an alert when the gear is down and the flaps are not in landing position. If the envelope is penetrated at less than 0.28 mach with the flaps not in the landing position, the aural alert TOO LOW FLAPS is sounded. When the envelope is penetrated at more than 0.28 mach, the aural alert of TOO LOW TERRAIN is sounded and the upper boundary is increased to 1000 ft rad alt. The voice messages continue to occur until the flight condition has been corrected.
The TOO LOW GEAR alert take priority over TOO LOW FLAPS. The TOO LOW FLAPS and associated TOO LOW TERRAIN alert are inhibited with the flap inhibit switch when moved to the FLAP INHIBIT position

P.S trigger speeds may vary with aircraft type

[alkor]

exactly.

DO NOT disengage GPWS.

cheers,
a

[L'Argonauta]

What if you are in IMC? I think disengaging Egpws is not a good idea...I posted the same question on Tech Forum and many runers told me that even their planes have problems on EGPWS using QFE...so i think i have to do the maths!!

!:zzz:

[macjet]

- Which plane do you fly?
- Is the EGPWS software up to the latest revision?

Disengaging the itself capable system is not a good idea - Pilots doing the math is even worse...

mJ

[H.Finn]

Flown in the former USSR for as long as GPWS and EGPWS have been around, always used QFE and never had any warnings. Exceptions being arports which are not included in the EGPWS database, that is airports where you will have to use a local navigator to supply charts and act as an interpreter for ATC.

[Romasik]

Well, with GPWS it's clear - it's a dumb thing that only reacts on your radio altitude, configuration and speed. As for EGPWS - it's a different beast which uses terrain database with terrain elevation measured from MSL. Whatever your atimeter setting, it thinks it's QNH, and gets upset when you are actually on a perfect glideslope at a more or less elevated airport. So, use QNH and do your math. Disabling EGPWS is a bad idea, especially in IMC.

[Lazy Bird]

I agree with H.Finn.
we had troubles with terrain warning using QFE on few airports only.
Usually a call to Honeywell solves your problem after the next database update!
As you know, flying in russia might keep you busy, (seldom flights to russia, language, navaids, procedures, young collegues.......) then good luck on your maths. What is the higher risk if you are well prepared??

Let them spend the money and provide us with well consistent databases!

[theloveman72]

Talking altimeter setting in Russia. Any of you know if ATC will provide descent altitude corrected for low altimer/low temperature ?

I have heard that somewhere but i want to confirm it. It may be not usefull in Moscow but if you land in Petropavlosk (UHPP), with basic radar, that volcano gets very close if you have a bad altimeter setting.

[Red Goose]

Our company policy is to use QFE when flying in the CIS. And I think it is a good idea, as it allows less room for error, either from the controller converting QFE to QNH, or from me readind the wrong altitude on the Jeppesen chart conversion table ( if I am cleared to 600m height, and I read 2600ft (QNH) instead of 1920 ft (QFE), at least I am on the safe side). Previous example is for an airport at an elevation of 680 ft (Moscow UUWW).
If your FMS software is not adapted to QFE, you will get a terrain warning on approach when you reach the field elevation (i.e 680ft in Moscow UUWW), if you are flying in QFE. If that is your FMS condition , it might be better to fly QNH...

[galaxy flyer]

It depends a bit on where your EGPWS is getting its position information and is it "enabled". In the Honeywell and R-C systems I fly, if you leave the GPS enabled, the EGPWS should work fine, if the airport in the database and the DB is up-to-date, regardless of QFE or QNH. The EGPWS works off of GPS and WGS-84 which is the datum that the DB elevation and obstacle information is formatted.

However, you cannot use VNAV or FMS approach in QFE operations due to incompatible altitude information. You must fly approaches in raw data.

If the FMS enters landing elevation for pressurization, it needs to be put in Manual and a manual elevation of Zero entered.

It would be easier if we could enter "0" in the FMS landing elevation, all would be well.

You must turn off TERRAIN, if you have disabled the GPS receivers, btw. Because the EGPWS has no GPS positional information to work with.

GF

[PicMas]

I still maintain that if:

The controller is used to give altitudes based on QFE, the pilots should set QFE to avoid pilot and controller error in the conversion - as posted above.
The controller may very well agree to give QNH, and may correctly do so, if there is a handover or the controller looks at his scope and sees you entering a certain sector for the approach, there is a minute chance he will pass the same (QFE-based) altitude as for the previous 1,000,000 aircrafts, a well-known scenario for error based on law of recency.

In that case if:

The gadgetgizmo gives you warnings, and there is no sensible way to correct this ie. update database etc, the warning feature should be disconnected. The gadget - whatever it is - is not what is keeping the aircraft from hitting the ground. There are, for most Russian installations, two NDBs with corresponding altitudes, DME, timing and of course a glideslope or an AZELscope.

My vote is still for:

Fly QFE - to avoid conversion workload (this may already be increased due to conversion from meters to feet) and habitual clearances from ATC.

Disconnect known warning - The idea of ignoring a warning (if it can not be corrected).... no need to discuss that one I think.

The EGPWS is there to, among other things, warn about altitude being too low for a particular segment of flight, if it is known prior that this function is not performing as intended it should be disconnected. When it, on short final to Vnukovo, gives the TOO LOW TERRAIN warning this is incorrect.

[ahramin]

Not all EGPWSs use radar altitude.

[Son of a Beech]

Not all EGPWSs use radar altitude.

Mode 4 does, use RADALT

for the rest EGPWS uses geomatric altitude:

Geometric Altitude is a computed aircraft altitude designed to help ensure optimal operation of the EGPWS Terrain Awareness and Display functions through all phases of flight and atmospheric conditions. Geometric Altitude uses an improved pressure altitude calculation, GPS Altitude, Radio Altitude, and Terrain and Runway elevation data to reduce or eliminate errors potentially induced in Corrected Barometric Altitude by temperature extremes, non-standard altitude conditions, and altimeter miss-sets. Geometric Altitude also allows continuous EGPWS operations in QFE environments without custom inputs or special procedures by the flight crew when operating in a QFE environment. Required Inputs for Geometric Altitude The Geometric Altitude computation requires GPS Altitude with Vertical Figure of Merit (VFOM) and RAIM failure indication along with Standard (Uncorrected) Altitude and Radio Altitude. Ground Speed, Roll Angle, and Position (Latitude and Longitude) are used indirectly and are also required. Additionally, Corrected Barometric Altitude, Static Air Temperature (SAT), GPS Operational Mode and the Number of
Satellites Tracked are used if available. The required GPS signals can be provided directly from an external ARINC 743 / 743A receiver or from
the optional internal EGPWS Xpress GPS Receiver card. Standard Altitude, Corrected Barometric Altitude, and Static Air Temperature (SAT) are provided directly from the ADC. If SAT is not available, geometric altitude is computed using Standard Altitude with a corresponding reduction in accuracy.

Remember: The whole point of EGPWS and GPWS is based on warning the pilot for the mistakes a pilot made!!

SOAB

[galaxy flyer]

SOAB

Thanks for the very complete answer on how EGPWS gets its positional information and I agree except:

If an FMS uses GPS positional information for FMS Approach, in non-WGS-84 airspace, one must disable the GPS receivers and use DME-DME FMS information for FMS Approach or go Raw Data. GPS cannot be used for approach navigation in non-WGS-84 locales. Yes, the EGPWS works fine with GPS in non-WGS-84 airspace for warnings. Be careful about datums and the CIS isn't about to change to WGS-84.

GF

[ahramin]

Galaxy flyer, instead of disabling the GPS inputs, why not get the navdata for the datum used in that airspace and use that datum?

Quote:
Not all EGPWSs use radar altitude.
Mode 4 does, use RADALT
Class B TAWS are specifically not required to have RADALT. Mode 4 is accomplished through using takeoff elevation when RADALT is not available.

Relationship between GPWS and FLTA

FLTA produces alerts from things ahead of the airplane using a terrain database, GPS position, velocity, etc. GPWS produces alerts from things underneath the airplane and alerts from configuration, such as excessive descent rates while close to the ground, gear and flap warnings during landing, etc.
The FLTA features in Class A and Class B are identical and represent the same level of safety. The main difference is in the GPWS portion of the system. Class A requires a "fully autonomous" GPWS while Class B does not. The practical effect of this means:

Class A requires Radar Altitude and Class B does not.
Class A requires Airdata and Class B does not.
Class A requires both Gear/Flap inputs and Class B does not.
Class A requires an STC and Class B does not. (Money and time!)
Class A requires a map display and Class B does not. This does not mean, however, that a Class B lacks all the GPWS features. Instead, what was done in the regulation was to specify a minimum feature set in Class B which could be implemented by substituting "synthetic radar altitude" derived from the terrain database and GPS altitude to allow most of the GPWS alerting functions. Class B GPWS alerts are not autonomous, because failure of the GPS receiver will fail both FLTA and GPWS. In a Class A system failure of GPS will not fail the GPWS.

[Lear Jockey]

We had the same warnings. I suggest you keep the EGPWS on and don't, never, appart from flying into known mountainuous area and being VMC, shut it off!:=

If you quickly have a look on the Jepp charts, you'll find [B]both[B] QFE and QNH altitudes written on the side of the charts, STAR's, approach and even SID's. The matter is to have a look at the field elevation, convert it with the QFE given into QNH (add 1 hPa per 30 feet of elevation). When first contacting approach, ask them for QNH and compare with what you have. It is usually within 1 hPa anyway.
Then when ATC clears you to and altitude in meters QFE, you don't care, you compare the meters into the QNH on you Jepp chart and that's no more calculation!
Have a good flight!

[PicMas]

So you had the warnings? What did you do? continue?

I dont think anybody suggested turning off the EGPWS - Just the terrain warning.
What you suggest adds an extra step in each stepped descend, which basically means an extra opportunity to get it wrong for each descend clearance.

[jetopa]

Exactly! Fly the f...cking aircraft.

And one more thing: the 'USSR' ceased to exist in the 90s. It's either 'Commonwealth of Independent States' (CIS) or simply Russia, Kasachstan, Ukraine etc...

Last time I heard, the people there highly appreciate not to be called 'Soviets'.

[roljoe]

Totally agree with Jetopa,

this should have been the first remark to be posted...

About the primary object of the post...fly QFE..with a conversion table on your yoke..(jepp approach and/or jepp low/high level charts)..keep it simple..you'll never get a intermediate altitude or level not charted..

About the egpws..the main reason for activation is the non wgs standard used by russian and others in that world area..but nothing to be affraid for as long as your basic flying skills are present on the flight deck..

After a 20 years experience around this part of the world..I have just to mention that theyr have done a huge progress...and no more ak47 while opening the doors since a long time ago..

Happy trails...

[rsiano]

The Russians are gradually making their reference datum of PE-90.02 coincide exactly to WGS-84. Today, April 1, 2010 the maximum difference is half of a meter at worst and at best only six inches difference. Another adjustment to the PE-90.02 datum is to be made next year bringing it even closer to the exact same datum as WGS-84.
I believe with the two datums so close to one another, today I would leave my GPS sensors enabled while flying in Russia and the Commonwealth of Independent States. A maximum error of 18 inches will probably be not noticeable to the flight crew.
Thanks!
Dick Siano
Pilot Instructor FlightSafety International Teterboro, NJ

[galaxy flyer]

rsiano

Do you have a reference document available on PE-90 datum showing that information? I've searched a lot and cannot find one.

GF

[macjet]

still we don't know which airplane gave the warning...

maybe with the a/c type and the installed (E)GPWS and the manufacturer and maybe the software version we can find out more...?

happy easter

MJ

[pullup hard]

Do not use QFE if your aircraft is not pin-programmed for it. Do not switch of EGPWS, it is your life-saver in IMC.
Use QNH below TL: PF will set cleared ALT according to JEPP (or other) Approach plate table (on JEPP the NON-bracketed Altitudes) and your PNF will crosscheck for correctness.
Not rocket science.:ok:

[FixedRotaryWing]

Do not use QFE if your aircraft is not pin-programmed for it. Do not switch of EGPWS, it is your life-saver in IMC.
Use QNH below TL: PF will set cleared ALT according to JEPP (or other) Approach plate table (on JEPP the NON-bracketed Altitudes) and your PNF will crosscheck for correctness.

You have never been in UUWW. What will your PNF crosscheck on "decent height 400 meters, cleared ILS"? You will not find this height converted to an altitude on a Jepp approach plate. Converting a height in meters to an altitute in feet shortly before an 90° ILS intercept is lots of fun...

[Sepp]

Last time I went to UUWW, the imperial equivalents of 400 M QFE - both QFE and QNH - WERE shown on the ILS 02, 06 and 20 approach plates... in the little box in the bottom right hand corner of the horizontal profile.

[keepin it in trim]

We operate on QFE on main alts, with standby set to QNH, below transition. We also have the advantage that our Pro-line 21 displays metres alongside feet when selected.

As an aside, the AIP for Russia requires you to operate QFE below transition, within I think about 25 miles of the field. Our company policy is to comply with this, the only exception being in the event of very low QFE.

Our EGPWS does not have any problems with this. Daylight, VMC, absolutely sure that there is no hazard, we may continue with a "terrain" call - a "whoop, whoop, pull up" is mandatory response for us.

Enjoy:)

[notanastronaut]

"When in Rome do as the Romans do." Use QFE.
NAA

[keithskye]

We operate on QFE on main alts, with standby set to QNH, below transition. We also have the advantage that our Pro-line 21 displays metres alongside feet when selected.

As an aside, the AIP for Russia requires you to operate QFE below transition, within I think about 25 miles of the field. Our company policy is to comply with this, the only exception being in the event of very low QFE.

Our EGPWS does not have any problems with this. Daylight, VMC, absolutely sure that there is no hazard, we may continue with a "terrain" call - a "whoop, whoop, pull up" is mandatory response for us.



Simple and straightforward. If you cannot display meters on your altimeter, then you will need to convert. I have a very nice, one-page conversion table with all the necessary numbers you'll likely ever need when operating in Russia, Ukraine, etc. PM me and I'll send it to you by email. I keep a copy with me all the time, in case my Pro-Line 21 goes TU on me. I also have one for flying in China and would be happy to share that as well.

Keith

[galaxy flyer]

pulluphard

The EGPWS database and GPS both work on WGS-84, so as long as the GPS navigation is enabled in your FMSs, the EGPWS won't be affected by operating in PE-90. However, disable the GPS, so the FMS is working on DME/DME positioning, all bets are off.

Us clever running dogs of capitalism, mapped the world's surface without regard to local authority, but couldn't do the same for things like navaids.

GF

[Denti]

@notanastronaut

Without consulting the restrictions of your airplane, AOC etc?

For example the 737s we fly and used to fly to Russia can not be operated I. QFE, that is a very strict restriction by Boeing ("prohibited"). Operating in QNH is not a problem at all though as the Lido eRoutemanual has all the information needed (back when we used jepp they had it too, only the EAG material was insufficient and aditionally plagued with a very bad chart representation). Not to mention that you actually get a QNH if you ask for it, at least at the aiports we operate to including the Moscow area.

[Don Coyote]

If the aircraft is set up to work off QNH, including the GPWS then you will need to operate to QNH; otherwise you may get in the habit of ignoring GPWS warnings.

I have had a bit of experience operating an Airbus into CIS airfields and that would only work if QNH was selected (it is possible to have the aircraft operate to QFE, but that is an engineer function and is not selectable by the pilot). We also used AERAD approach plates which gave the height and altitude on the same chart.

The principle is straightforward, when given QFE by ATC you apply the correction given on the approach plates to convert it to QNH. When cleared to a height by ATC you then look at the chart and next to that height will be an altitude; you then simply fly to the altitude. ATC give you a small number and you fly to the big number - simple and no problem of crews having to convert and making a mistake.

As mentioned earlier, you will not get cleared to intermediate heights. If you go to an airfield frequently, as we did, then your company may wish to prepare conversion charts for that airfield that has all the information on one page which makes life a little easier.

Ideally, your operator should have procedures laid down in the operations manual detailing how you fly the aircraft in these areas. They normally appear in the Part C, if they don't then file an ASR and get them to put procedures in place.

[FalconFlyr]

..what's wrong fastjet45 .....not enough razor blades for breakfast. It is regrettable that the debate has continued after your definitive statement on the subject....

....and by the way your mate Don Coyote is not correct - operating on QFE as per the Russian AIP does not necessarily mean you'll grow to be immune to GPWS warnings. Depends on the equipment - many EGPWS use geometric data from GPS and work perfectly well regardless of what is set on the Altimeter.

Still you don't strike me as the sort to appreciate the subtleties of......well anything really...:rolleyes:

[Dumbledor]

If your SOP is to fly approches QNH then why not fly approaches in CIS on QNH too?

If you put QFE on the altimeters the EGPWS thinks you are lower by exactly the TDZE.

The GPWS will give terrain warnings for AP elev above 300', if I remember rightly if you do the approach on QFE. (VKO elev is 700' and Almaty 2200?) Riga volmet gives the QNH for some of the airports also for a double check. QNH can sometimes be obtained from approach control.

QNH = QFE + TDZE/27.

Converting metric Height to imperial altitude is no more difficult than converting metric height to imperial height. The conversions are on the approach chart.

Keeping SOP's unchanged as far as possible by flying QNH to compare with altitude with MSA, and by keeping the EGPWS working correctly is surely safer all round by reducing risk of CFIT.

D

[Don Coyote]

FalconFlyr,

With regard to ignoring the GPWS warnings I was referring to aircraft that are designed to be flown on QNH, and where the GPWS datums are taken from the QNH (i.e. Altitude) this causes false GPWS warnings if the aircraft is flown with QFE set; if this happens every time you are flying a QNH designed aircraft in CIS airspace then the human factors element would naturally lead to assuming that GPWS warnings in CIS airspace are spurious.

The important point is that instead of arguing about it here, Chief Pilots/Training Departments should be addressing these issues and setting out operating procedures to be put into operations manuals. Line training/recurrent training should then ensure that crews are aware of the appropriate procedures.

As has been mentioned already, it is not difficult and it is even easier if it has been thought about beforehand.

[notanastronaut]

@Denti

Thanks for the post.
Indeed, in some of the larger airports you can request and be given a QNH value, HOWEVER all the altitude clearances provided by ATC, including krug are always given with reference to QFE, never QNH.

Many thanks.
NAA

[Dumbledor]

notanastronaut,

You're right 'Krug' ('director' to us I think?) will always clear you down to a heights by QFE for the approach. It's just a bit of simple but careful cockpit work to turn the metric height into an imperial altitude with QNH set (or metric altidude if your a/c has a metric option) via the jepp approach chart. The heights that you will be cleared to and their conversions are all on the chart so you can make a note of them in the approach briefiing. The PNF could write down the actual clearance and the imperial altitude next to eachother.

As said before at least the EGPWS is still valid with QNH on the altimeters and you can compare your altitude with MSA / vectoring minima. It's safer all round.

I find it useful to keep climb and descent rates down a bit as the sectors seem to be seperated vertically, for example you often need to change freq to get a further climb/ desc. If you call approaching the level/alt around 1000' (a trick I learned from a Russian navigator!) before you may have time to change freq, check in, get a further climb/desc, convert & set it.

D