hi guys
can anyone explain to myself how can see aircraft in myflights to show being on the ground instead of showing levelled? as i only live a few miles from Leeds Bradford Airport i know when certain aircraft are on the deck!
cheers for any help
mark
Hi Mark
Use the Quickfilter above the MyFlights grid:
Set the first field to Status, set the centre field to = and click the button beside the third field - you'll want "0Ground" then click the Filter button.
That should do it.
EDIT - Does anyone know what "5Deleted" is meant to show???
Rod
cheers Rod
Make sure you set Leeds Bradford (EGNM) as the airport to get the QNH (currently 1011hPa) from in SmartView - tick the Autoset QNH tickbox. Then aircraft should show as on the ground when at 0ft QNH.
Tarbat
I am having trouble with this as LBA runway is at 681 ft.
Okay, I've got no way of testing this, as all runways near me are almost at sea-level. I always thought that setting the QNH would fix altitute readouts correctly. So, check that:
1. You've got autoset QNH ticked, and the correct airport setup, on Smartview, and the QNH pressure is correctly set.
In my screenshot, I have EGQK (Kinloss) selected as the airport, and that is currently reporting a QNH of 1017.
2. You've set the transition altitude in preference. I have mine set to 9999, so that anything below 10,000 feet (FL100) is corrected for the airport QNH.
See screenshots attached.
Tarbat,
There is no such thing as 'airfield QNH'. QNH is the barometric pressure at mean sea level (AMSL) for the region. Therefore, if you set QNH for the area it will always show the airfield's height above mean seal level. The barometric pressure at airfield level is known as the QFE and when set on a barometric altimeter will show 0' at airfield level.
The setting in preferences is to set the QNH so that aircraft show their height above mean sea level below the transition altitude set in the box above. Because the airports around you are almost at sea level, setting the correct QNH will result in the ac being shown at or around 0' when on the ground but at any other airport the height will always be the airport's elevation above mean sea level.
Tom
Setting the correct QNH will cause the altitude above mean sea level to be displayed. To display 0 on an airfield would require the QFE to be set. Pressure is measured in hectopascals as far as the UK is concerned (1hPa is the same as 1 millibar, the US measure pressure in inches). For our purposes we will assume that 1hPa is equivilant to 30 feet. Leeds is published as elevation 682 feet, so the QFE will be 682/30=22.73hPa different to the QNH. If you subtract 23 from the current QNH and enter it in the File - Preferences - QNH box as per Tarbat's screenshot you should see aircraft on the ground reading as 0'. Hope this helps
Tarbat
Sorry. I read too much into the 0 in 0ground. Tried it on network flights and could see aircraft on the gorund at Prestwick and Skipol. Will try it at Stansted when one lands.
At least I now know where the machine gets QNH
Dudley
Dudley,
Stansted is 348' amsl so the QFE right now (QNH is 1015) would be about 1003hPa
Keith
Understand now - thanks. So, with the correct local QNH set in RB, the altitude of an aircraft on the runway will show as the airfield height above sea-level.
I also understand that some types of aircraft which are on the ground may be sending out 0ft as part of there computer system, just to indicate they are on the ground - as per this post from Airnav - http://www.airnavsystems.com/forum/index.php?topic=1728.msg13704#msg13704
Locally to me, aircraft are generally instructed to set "clutch QFE" or "clutch QNH", depending on whether they're using the bombing range or not. See http://www.airnavsystems.com/forum/index.php?topic=1048.msg7944#msg7944
At least Radarbox does correct for local QNH. The SBS-1 Basestation makes no such correction, and I used to regularly see Tornados flying at NEGATIVE (-200ft) altitudes on my SBS-1.
Hi Tarbat, Ah, so you really are human like the rest of us! A very useful and enlightening thread for all of us.
Quote from: tarbat on February 11, 2009, 10:20:47 AMAt least Radarbox does correct for local QNH. The SBS-1 Basestation makes no such correction, and I used to regularly see Tornados flying at NEGATIVE (-200ft) altitudes on my SBS-1.
No wonder the neighbours complain about dangerously low flying!
Hi
I pressume the Clutch is Lossie and Kinloss. There is a clutch for Brize and Lyneham. Clutch pressure is used in preference to Airfield QHN. Regeonal pressure settings are change hourly but airfield and clutch may be more often.
Dudley
Hi
Unfortunatly, 0ground does not always work. I have just monitored 3 aircraft on the ground at Stansted all at 370 ft. Do not show on Status 0ground but listed for Altitude < 400 feet. Along with several timedout.
Dudley
Quote from: dudbaker on February 11, 2009, 11:41:55 AM
Hi
I pressume the Clutch is Lossie and Kinloss. There is a clutch for Brize and Lyneham. Clutch pressure is used in preference to Airfield QHN. Regeonal pressure settings are change hourly but airfield and clutch may be more often.
Dudley
Dudley,
There is no such thing as 'airfield QNH'. Barometric pressure at field elevation is QFE.
Tom
Tom
Just checked London Volmet 128.6, Stansted Atis 127.175 RAF Volmet on 5450 and all giving QNH. Lippetts Hill police helicopter site is giving QFE.
Dudley
Quote from: dudbaker on February 11, 2009, 02:15:26 PM
Tom
Just checked London Volmet 128.6, Stansted Atis 127.175 RAF Volmet on 5450 and all giving QNH. Lippetts Hill police helicopter site is giving QFE.
Dudley
Dudley,
In my experience as a pilot (retired now), most general aviation airfields and helicopter operating bases without ILS inform the pilot of the QFE so that he/she can join the circuit at the correct height.
Volmet and ATC services give QNH as they are 'area' based. ATC requires all aircraft to have their barometric altimeters set to the same datum for a particular FIR in order to maintain proper vertical separation. Aircraft also need to know what their height AMSL is as that is what the height of obstacles such as mountains etc is indicated on maps and charts.
Tom
In case others are wondering why the codes QFE and QNH are used, they are part of the three letter 'Q' codes invented when the Morse Code was the primary means of long distance radio communication. Some others are:
QNE - Atmospheric pressure at sea level in the International Standard Atmosphere (1013.25 hPa)
QDM - Magnetic bearing to a station.
QDR - Magnetic bearing from a station.
QFU - Runway in use (e.g. QFU 29 - Runway 29 in use).
QTH - What is your position?
QSY - Change frequency (e.g. QSY 123.40)
and my favourite:
QRM - Are you being interfered with? :-))
Tom
A question I've raised before and still puzzles me a bit is what barometric pressure do pilots use to set their altimeter. I hear ATC telling pilots to set both QNH and QFE. What rules (if any) determine whether a pilot sets their altimeter to QNH or QFE?
Secondly, is this barometric altimeter always used to set the ModeS/ADS-B altitude, or does this sometimes come from the aircraft's radar altimeter? This question particularly applies to military aircraft operating low-level.
Tom
Totall agree with all that. I notice that Northweald has a circuit height of 800 aal. What ever aal is. Stansted Stars all use QNH. Stansted Terminal chart gives both. For overshoot for example.
Tarbat
They all used to use QFE. Then for a while ATC would ask the captain what was wanted. (Company Policy). Both were on ATIS but now only QNH. Now QNH unless radalt problem. See MEL 34 42 02. If automatic call out not working operating procedures to be ammended to allow for manual calls.
Now I always thought mode C came from one of the altimters and ATC would see what the pilot sees. I was corrected by Allocator and Dave Reid, on one of the forums here. I checked my A320 notes and sure enough the transponer sends Standard. ie 1013.2. From the Air Data Computer not Radalt. Hence, as you have said on many occasions you need to set QNH on RB either manually or Automaticlly.
I am asssuming altitude reporting was changed because of a crash into the sea. Aircraft cleaners had left tape on the static vents. The pilot new he had a problem so asked ATC for his height. Unforunatly, ATC saw the same as the pilot and the aircraft hit the water with a reading 4000 feet. This may not always help but to you have more than one sourse is better.
It might be fun to set QFE on RB but would not make much diffence where you are.
Used to come up to Lossie to fly Canberras as silent targets for 8 Sqn Shackeltons.
Dudley
Quote from: dudbaker on February 11, 2009, 04:33:19 PM
Tom
I notice that Northweald has a circuit height of 800 aal. Whatever aal is.
aal = above airfield level
Quote from: tarbat on February 11, 2009, 03:40:41 PM
A question I've raised before and still puzzles me a bit is what barometric pressure do pilots use to set their altimeter. I hear ATC telling pilots to set both QNH and QFE. What rules (if any) determine whether a pilot sets their altimeter to QNH or QFE?
Secondly, is this barometric altimeter always used to set the ModeS/ADS-B altitude, or does this sometimes come from the aircraft's radar altimeter? This question particularly applies to military aircraft operating low-level.
Tarbat,
I answered your question regarding use of QNH/QFE a few posts back.
I think you will find that the radar altimeter is not reliable above/not used above 2,500 ft. So above that altitude it will be the baro alt that provides the input.
Tom
Quote from: viking9 on February 11, 2009, 05:56:29 PMI think you will find that the radar altimeter is not reliable above/not used above 2,500 ft. So above that altitude it will be the baro alt that provides the input.
Mode S altitudes (and possibly Mode C, though I'm not sure about that) may alternatively be GNSS-derived.
I checked my A320 notes and sure enough the transponer sends Standard. ie 1013.2.
There is a switch on the transponder marked - Alt Rptg or off. The note that goes with the switch says - Baro standard data is transmitted.
Dudley
cheers guys for the excellent help!
mark
Hi
Found this. http://www.nats-uk.ead-it.com/aip/current/enr/EG_ENR_1_7_en.pdf
5.3.1 When an aircraft is descended from a Flight Level to an Altitude preparatory to commencing approach for landing, ATC will pass the appropriate aerodrome QNH. On vacating the Flight Level, the pilot will change to the aerodrome QNH unless further Flight Level vacating reports have been requested by ATC, in which case, the aerodrome QNH will be set following the final Flight Level vacating report. Thereafter, the pilot will continue to fly on the aerodrome QNH until established on final approach. When requested by the pilot or local procedures require, the appropriate QFE and aerodrome or threshold elevation shall also be given.
Dudley