Primarily for general aviation discussion, but other aviation topics are also welcome.
By AlanM
#1667770
GolfHotel wrote:To those that were interested in the original thread. I apologise for giving people who wish to nit pick rather than make a positive contribution a chance.

I thought the thread showed a couple of positive points. Unfortunately they have totally been lost following @AlanM finding it more appropriate to concentrate on a slip I made rather than the quite frankly much more important positives.

Such is life. Unfortunately.


Wow! Quite the outburst.

May I suggest a re-read from the top. I sent an answer as to which QNH was needed, an explanation of how the QNH is input into the Radar Data Processor and a link to the ENR section of the AIP.

I also praised the OP for his use of a listening squawk.

Well at least we all now know that CTRs in Italy are not to the surface (in case the OP goes there)

I am genuinely smiling at your outbursts.
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By AlanM
#1667777
Lockhaven wrote:
Iceman wrote:Tim, could you illustrate a CTR that doesn't touch the surface ?

Iceman 8)


I believe you can fly under the Cardiff CTR whilst flying over the water but not 100% certian so dont try this at home until checking first.


From the CAP 393: The Air Navigation Order 2016 and Regulations.

“Control zone” means controlled airspace which has been further notified as a control zone and which extends upwards from the surface

So, the sea and land are considered to be surface.

*unless in Italy and probably other jurisdictions.
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By Iceman
FLYER Club Member  FLYER Club Member
#1667781
Lockhaven wrote:
Iceman wrote:Tim, could you illustrate a CTR that doesn't touch the surface ?

Iceman 8)


I believe you can fly under the Cardiff CTR whilst flying over the water but not 100% certian so dont try this at home until checking first.


I believe that that was Maurice Kirk's defence once against having done exactly that.

Iceman 8)
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By Pilot Pete
#1667820
Slight thread drift (ok huge)
I would like to comment on the excellent service I've had from Luton on several transits lately.
A couple also included a Traffic Service a welcome distance outside their class 'D' despite being busy.
While avoiding Stapleford I consciously veered further south to avoid an aircraft that they hadn't seen (possibly microlight sans transponder), and the nice man came on the radio just to check I wasn't goung to bust the London city zone. ( Which I wasn't)
Top service.
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By GolfHotel
#1667834
AlanM wrote:
I am genuinely smiling at your outbursts.


I’m hardly surprised that you consider my comments outbursts, while apparently being happy to be pedantic to the detriment of the thread.
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By T67M
FLYER Club Member  FLYER Club Member
#1667864
xtophe wrote:I was under the impression that the vast majority of ATC SSR setup automatically convert the relevant mode C/S flight level to altitude. It must be requirement for the system with control airspace infraction detection.

So I would think it is a problem with the OP altitude encoder. But his transponder was displaying the correct FL. So quite confusing.


So the OP was flying well below controlled airspace, using a QNH which was either correct or within 1hPa, their transponder was indicating the correct FL to correspond with their actual altitude, yet Luton's controller see them as an infringer. Sounds like some more investigation work is required to understand why the flight appeared to be infringing when it wasn't.
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By Flying_john
FLYER Club Member  FLYER Club Member
#1667892
Please explain. I too looked at this on my return, but could not see how to get an altitude graph similar to SD or RunwayHD does at the bottom of the display.
By PaulB
#1667894
T67M wrote:So the OP was flying well below controlled airspace, using a QNH which was either correct or within 1hPa, their transponder was indicating the correct FL to correspond with their actual altitude, yet Luton's controller see them as an infringer. Sounds like some more investigation work is required to understand why the flight appeared to be infringing when it wasn't.


I've been reading this thread on and off and that was my thought too. Further, was this recorded as an infringement that will appear in the stats that make us all look bad?
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By Iceman
FLYER Club Member  FLYER Club Member
#1667907
May be an engineering check of the aircraft's altimeter and its calibration is required. Or perhaps the aircraft's altitude encoder has an offset/gain problem. If the aircraft's transponder has a pressure altitude readout then it would be a useful exercise for the OP to set 1013 on the altimeter and compare the transponder's pressure altitude readout with the altimeter at various levels in order to see if there is any discrepancy.

Iceman 8)
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By Flying_john
FLYER Club Member  FLYER Club Member
#1667955
He have on board an EFIS with Alt readout, A steam driven conventional Altimeter, A GPS running RunwayHD and an MGL altimeter, all tested (well not the GPS) at the last annual with a test set and they all agreed with each other +- a little/
The txpdr has an FL readout, which when the other on-board altimeters had their subscale set to 1013, agreed with the FL reported on the front panel of the Txpdr.

The controller who spoke to me was very nice, there was no mention of an MOR and I was not asked to telephone them. I simple descended another 200 feet to an indicated 2000 - 2100 feet and heard no more.
By PaulB
#1668066
Flying_john wrote:The controller who spoke to me was very nice, there was no mention of an MOR and I was not asked to telephone them. I simple descended another 200 feet to an indicated 2000 - 2100 feet and heard no more.


But the base is 2500' and you were below that anyway. In effect, this is making the effective base drop by 100' for every 3hPa the pressure falls below 1013.25hPa. I wonder whether the opposite applies when the pressure is high? :-)

I saw mention of the base of the LTMA being relative to Heathrow's QNH. I don't fly in that area much. What QNH would ATC give to aircraft flying in that vicinity?