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Feature Request: TDZ Lights

Started by tango4, Tue, 23 Dec 2014 14:39

Hardy Heinlin

Actually, the rosy sector itself now has a gradual color change. There's no switch effect at all anymore, not even a switch to/from rosy :-) Even though the transit takes just 3 arc minutes (0.05°), it looks much more realistic this way, i.e. smoother rather than flipidee-floppidee.

Tom Gorzenski

#41
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 07:09
Actually, the rosy sector itself now has a gradual color change. There's no switch effect at all anymore, not even a switch to/from rosy :-) Even though the transit takes just 3 arc minutes (0.05°), it looks much more realistic this way, i.e. smoother rather than flipidee-floppidee.

Yes, it's true that a there is normally a color transition zone between red and white, in any PAPI/APAPI light unit. Please note that 3' is the absolute maximum allowed as per ICAO Annex 14, point 5.3.5.30. See also ICAO Doc 9157 points 8.3.8 and 8.3.9. The color transition to be considered satisfactory sharp, should appear virtually instantaneous when viewed from ranges in excess of 300 m. The transition zone can not be greater than 3'.

You wrote earlier that presently (10.149), the transition sector is only 0.0001°. I have found it to be more like 0.005° or 0,0001 rad - approx 2 ft from 3.0 NM, which is about 0.3 arc minute. So, this is approx. 10 x less than the maximum limit established by ICAO. Understand you are going to make it now 10 x wider, right at the maximum limit established by ICAO. Thats' fine but you might take into consideration that modern PAPI LED systems tend to have a bit better performance than 3'.

Hardy Heinlin

You mean I should reduce it to 2 minutes? :-)

Tom Gorzenski

#43
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 12:40
You mean I should reduce it to 2 minutes? :-)

Well, I can have more detailed information on that subject from some PAPI/APAPI manucturers next week (I have been involved recently in an aerodrome lighting project). But I have never heard in recent years that any PAPI or APAPI unit had failed to meet that requirement during certification tests or complete installation tests and flight test. So, I think they must do noticeably better than 3'.
I would be fine with 3' transition if you decide to make it so, but I would say 2' would be realistically just about right, most likely... :-)

Hardy Heinlin

Quote from: Tom Gorzenski on Fri,  7 Jan 2022 10:34
You wrote earlier that presently (10.149), the transition sector is only 0.0001°.

I was just kidding with an exaggeration, similar to the word "zillions". I don't recall the exact angle.

Tom Gorzenski

#45
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 13:36
Quote from: Tom Gorzenski on Fri,  7 Jan 2022 10:34
You wrote earlier that presently (10.149), the transition sector is only 0.0001°.

I was just kidding with an exaggeration, similar to the word "zillions". I don't recall the exact angle.

Understood :-)
P S. But you have been pretty close to the actual number, though... ;-)

Hardy Heinlin


Tom Gorzenski

#47
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 21:37
The 4-light PAPI is now implemented in PSX 10.150: https://aerowinx.com/board/index.php?topic=4191.0

|-|ardy

What?! I was supposed to go to bed... It will need to wait :-)
Thank you Hardy!

P.S. The PAPI works great! Good to have PAPI instead of APAPI...

Raj Hoonjan

Quote from: Hardy Heinlin on Fri,  7 Jan 2022 21:37
The 4-light PAPI is now implemented in PSX 10.150: https://aerowinx.com/board/index.php?topic=4191.0


|-|ardy

Currently, I use PSX in standalone mode only and this is a fantastic enhancement.

Thank you Hardy.

Mariano


Frans Spruit

Hi Hardy,

.150 is top!
Thank you very much,

Frans Spruit

Tom Gorzenski

#51
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 21:37
The 4-light PAPI is now implemented in PSX 10.150: https://aerowinx.com/board/index.php?topic=4191.0

Good day Hardy.

Could you please verify that the new PAPI angular sectors are exactly as depicted here:
https://www.easa.europa.eu/sites/default/files/online-publications/EasyAccessRulesforAerodromesRegulationEUNo1392014Revisionfro-75.png
?

I did some measurements of those sectors in the PSX today and found out, that while the "on glide path" (2 whites/2 reds) sector's width was pretty close to the expected 20 arc minutes, both the slightly low (1 white/3 reds) and slightly above (3 whites, 1 red) sector widths were approx 6 arc minutes each - only a bit more than a half of the normal width per ICAO standards - 10 arc minutes.

What I got for one particular runway (EHAM Rwy 06):
well below glide slope <2°45'
slightly below glide slope 2°45'-2°50'
on glide slope  2°50'-3°10'
slightly above glideslope 3°10'-3°15'
well above glidelope >3°15'

i.a.w. ICAO Annex 14:
well below glide slope <2°30'
slightly below glide slope 2°30'-2°50'
on glide slope  2°50'-3°10'
slightly above glideslope 3°10'-3°30'
well above glidelope >3°30'

Alternative ICAO sector widths for the purpose of better harmonisation of ILS glide path and PAPI signals to a point closer to the threshold:
well below glide slope <2°25'
slightly below glide slope 2°25'-2°45'
on glide slope  2°45'-3°15'
slightly above glideslope 3°15'-3°35'
well above glidelope >3°35'

Personally I would prefer the standard sector widths in PSX, because of the narrower "on glide slope" sector width - only 20 arc minutes, instead of 30 arc minutes (same as for APAPI, previously featured in PSX).

Again, many, many thanks for introducing PAPI to PSX :-)

Kind regards,
Tom

Hardy Heinlin

Can't verify your numbers.

For the sector separation, PSX uses these angles:

3.5000°
3.1666°
2.8333°
2.5000°


Regards,

|-|ardy

Dirk Schepmann

Thank you very much for the continuous improvement of PSX!

Tom Gorzenski

Quote from: Hardy Heinlin on Sun,  9 Jan 2022 15:52
Can't verify your numbers.

For the sector separation, PSX uses these angles:

3.5000°
3.1666°
2.8333°
2.5000°


Regards,

|-|ardy

Thank you Hardy!

To get my numbers I used "Basic 024 - Landing" situation, had the aircraft positioned of final approach at 1.5 NM KAG DME, motion off, and then was moving the aircraft vertically, observing all four PAPI lights to go from white to red. I noted the altitudes I got (from the Instructor/Situation/Position), which were used to calculate the angles. The altitudes noted were OK, but it looks like I must have made a calculation error, because after recalculation I got the new numbers very close to yours.

Just by flying in the sim everything felt right but the numbers did not match earlier, that's why I asked. I am sorry. The width of transition from white to red seemed to be approx. 5 feet, or 1.9' (max allowed by ICAO = 3'), just like mentioned earlier. Thank you!

Hardy Heinlin


Tom Gorzenski

#56
Quote from: Tom Gorzenski on Tue, 11 Jan 2022 11:18
Quote from: Tom Gorzenski on Fri,  7 Jan 2022 13:25
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 12:40
You mean I should reduce it to 2 minutes? :-)

Well, I can have more detailed information on that subject from some PAPI/APAPI manucturers next week (I have been involved recently in an aerodrome lighting project). But I have never heard in recent years that any PAPI or APAPI unit had failed to meet that requirement during certification tests or complete installation tests and flight test. So, I think they must do noticeably better than 3'.
I would be fine with 3' transition if you decide to make it so, but I would say 2' would be realistically just about right, most likely... :-)

Hardy, reference is made to my above comment...

I have received a LED PAPI unit test report prepared by an authorized photometric laboratory. Unfortunately I am not allowed to reproduce it here, or mention the name of the PAPI manufacture, however, I can quote the following excerpt from the report:

"C. Determination of transition zone:

Conditions: the transition zone must not be greater than 3 minutes of arc in depth, at azimuth angles up to 8 degrees either side of the center of the beam, expanding to no greater than 5 minutes 15 degrees either side of the center of the beam.

Measured transition zone at 25 meters:
  - in the optical center of the beams product, the transition zone has a width of 18 mm and by calculation it was obtained an angle of 0.04° or 2.4 minutes < 3 minutes, 
  - at 8° on either side of the center of the beam by calculation it was obtained an agle of 0.048° or 2.89 minutes < 3 minutes."

This is a wider transition zone than I expected...