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Marco Garegnani

ai traffic always miss approach at nairobi HJKJ

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Hello, I bought few days ago My Traffic X 5.4c and test it in Nairobi HJKJ. I noticed that the AI traffic during landing always miss the correct approach arriving too long to the runaway and then "go around". I see a lot of kenya airways airplane do that one by one. No one seems to be able to landing.... Of course the runaway is free and airplanes that are waiting for taking off are far distance to the runaway. The AI airplanes say "missed approach" to the ATC. Before buying My Traffic I had the World of AI packages and every landing was ok. (I have unistall these packages, so I don't think about conflict..).

I check the LIMC airport (milano malpensa) and over there the AI traffic was landing without issues.

 

How can i solve this problem?

 

thank you

 

 

marco

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I will check HJKJ, afaik it isn't below see level. Does this only appear the first about 20 minutes, or still later?

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Hi Burkhard, the problem still appears after 20 minutes, I checked it for about an hour. I think it is a 'my traffic' issue because no the default fsx or woai addon never had that problem. Please let me know if you have any news about, I fly a lot in Nairobi and with My Traffic is a pleasure with so much of airlines, but for that ugly problem..

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What I see, independendant of if the MyTraffic airport or the stock airport is used, 737-800 land too late , while A320, 737-200, 300 and 700 land fine. Does this also happen on your site?

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You will find a BR2_HKJK.bgl file in the MyTraffic scenery folder.  Locate the file and add passive to the end; e.g., BR2_HKJK.bgl.passive.  Go into FSX and retest. Now you're using the FSX stock HKJK. If you're still seeing issues after 10 minutes - a few of the first landings due to where FSX spawns them may come in too high or too low - you can rule out the MyTrafficX modified HKJK scenery.  Also, if you can list the plane types that have a hard time landing that would be helpful as well (I'm assuming that your observations are for the ILS landing on runway 6?).

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Yes I'm talking of ILS landing on 6 rnw.

Ok I have tested it again.

the result is that in about 50 minutes (from 5.50pm to 6.30pm):

- the first 2 airplanes (landing at 6.10pm) are gone too long and missed approach (737-200, 737-700, both kenya airways)

- than an A320 brussel air was landing well

- a boeing Kc israel airforce disappears just before landing, (about 2 miles from the runaway)

- the first 2 planes return for the second approach and now it goes well, perfect landing.

- a 747-400 klm was landing ok.

 

So maybe, both Burkhard and Kagazi are right.. the problem is where fsx spawns the first airplanes, but I never noticed it in other airports...

I noticed that as soon as landing, just before taxiing, the airplanes disappears, is it that with 100% ai traffic slide all the gates are occupied?

Thanks again!! Anyway I love mytraffic 5.4.

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The disappearence happens as soon as a landing plane finds no suitable parking. And here now something Needs to be done, the average size of aircraft has gone up here with local 787s and flights that were 767 gone up to A330, so I will check and see if more heavy gates can be created here for the next Version. Is anybody Aware if there have been real world modifications since FSX release?

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A few observations:

 

Stock FSX scenery: Most planes arriving from the west (approaching near HKNW direct to the NDB NO) had difficulty landing.  I tested with both MytrafficX and UT2.  AI planes do not use approaches. If an ILS exists, they will fly a pattern direct to the final approach fix at the altitude specified in the scenery approach header. In this case, the FAF is the terminal waypoint OM06. The approach altitude is 7,500 feet. The distance to the runway threshold is 3.9 NM.   When approaching from the west, the turn to final is a hard left at 7,500 feet and the AI planes I observed simply could not correct in time and land. Some came close but most went missed.  On the other hand, most straight in approaches from the south and west landed.

 

I tested again with a modified FSX stock scenery.  I reduced the approach altitude in the header for the ILS to 7,000 feet.  All planes landed including the ones flying from the west with the hard left to final.  The only drawback I observed was some AI that approached from the west clipped the mountain range just west of HKNW before entering the pattern.  It's possible that they also clip the range at the approach altitude of 7,500 feet as well.

 

Two fixes possible: First, reduce the approach altitude for the ILS at runway 6 according to the official charts. Second, keep the approach altitude and move the FAF out further. According to the charts, the FAF should be the NDB NO @ approach altitude 6,630 feet. I've also revised the parking per the latest airport charts. I'm going to upload the airport here once I've had a chance to test it.

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Attached file based on FSX default. I modified parking to reflect airport terminal charts. I also revised the ILS @ Rwy 6 per the latest charts. The IF is FD06 (8,300 feet) and the FAF is CF06 (7,500 feet). The FAF is 2.8 NM further out from the NO NDB (6,630 feet). This was done as to avoid AI approaching from a westerly direction from slamming into the mountain range west of HKNW.  A few other minor fixes and eye candy. To install simply add the two files to your MytrafficX scenery folder. Remember to remove or .passive the existing BR2_HKJK.bgl file. 

HKJK.rar

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Hi,

This is a very old topic, but I wanted to give you an insight on what might be the cause of this behavior. I too experienced a situation where some airplanes (in particular Boeing 737-800) approached the runway too high and declared a missed approach following a go-around (while other airplanes didn't have this problem). I checked the aircraft configuration file of the MyTraffic 737-800 AI-airplane and found the Oswald efficiency factor to be 7.50. In the Prepar3D documentation, I read that a value of 1 represents a perfect wing, so a value higher than one should produce an unrealistic flight behavior.

And indeed, after I changed the Oswald efficiency factor of the 737-800 from 7.50 to 0.75, the AI-plane approached the airport on a correct glideslope and no longer did a go-around. I presume that having a value of 7.5 made the airplane's aerodynamics "too good to be true", so it had difficulty gliding down the glideslope without gaining too much speed.

So if you experience this issue, try changing the Oswald efficiency factor in the configuration file of the respective airplane.

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