1 Topic by hardy

  • hardy
  • New member
  • Offline
  • Registered: 2022-02-07
  • Posts: 2

Topic: Possible FMC / AP Bug when passing 180° longitude

Hi,

I did some flights from NZAA to PHNL and back. In both directions the Aircraft turned out of the magenta line at the last waypoint before passing the 180° longitude while on the FMC / AP everything seemed to be OK. I suspect, that the AP tried to fly around the whole world to get to the next waypoint from the other direction in order not to pass the 180° line. Probably a wrong calculation?
Today I faced the same problem on my trip from RJTT tho PHNL - even with a Waypoint (29N180E) directly on 180° lon.

This behaviour is reproduceable.

The routes were:
- PHNL/26L BANZI1 LHAKE DCT DATBE G347 TARIB RIKDI1N NZAA/05R => At KADEN the aircraft turned into the wrong direction

- NZAA/05R RAXIN1Q TARIB G347 DATBE DCT CARRP OPACA4 PHNL/04R  => At MALNI the aircraft turned into the wrong direction

2 Reply by J.A.Romanov

  • J.A.Romanov
  • J.A.Romanov
  • Admin
  • Offline
  • Registered: 2015-02-15
  • Posts: 2,885

Re: Possible FMC / AP Bug when passing 180° longitude

hardy wrote:

Hi,

I did some flights from NZAA to PHNL and back. In both directions the Aircraft turned out of the magenta line at the last waypoint before passing the 180° longitude while on the FMC / AP everything seemed to be OK. I suspect, that the AP tried to fly around the whole world to get to the next waypoint from the other direction in order not to pass the 180° line. Probably a wrong calculation?
Today I faced the same problem on my trip from RJTT tho PHNL - even with a Waypoint (29N180E) directly on 180° lon.

This behaviour is reproduceable.

The routes were:
- PHNL/26L BANZI1 LHAKE DCT DATBE G347 TARIB RIKDI1N NZAA/05R => At KADEN the aircraft turned into the wrong direction

- NZAA/05R RAXIN1Q TARIB G347 DATBE DCT CARRP OPACA4 PHNL/04R  => At MALNI the aircraft turned into the wrong direction


Thanks for detailed info - we will make test flight using this route to understand what may happen wrong on FMGS side.

Please read a FAQ before you post a bug http://support.jardesign.org

3 Reply by hardy

  • hardy
  • New member
  • Offline
  • Registered: 2022-02-07
  • Posts: 2

Re: Possible FMC / AP Bug when passing 180° longitude

Thx a lot!

Just one additional information as it might be of interest in this case: I'm using the newest Navigraph AIRAC

4 Reply by J.A.Romanov

  • J.A.Romanov
  • J.A.Romanov
  • Admin
  • Offline
  • Registered: 2015-02-15
  • Posts: 2,885

Re: Possible FMC / AP Bug when passing 180° longitude

hardy wrote:

Thx a lot!

Just one additional information as it might be of interest in this case: I'm using the newest Navigraph AIRAC

Ok, understand.

Please read a FAQ before you post a bug http://support.jardesign.org