Thank you very much for all your suggestions.
Since the problem is not solved, I herewith give some additional information.
1. this is my configuration, not exactly a computer that is not able to digest the workload, I assume:
Corsair 780T +Corsair PSU 1000w
MBO Asus Max Vii Hero
Intel i7-4790k
Corsair H100i GTX cooling
G Skill 16gb 2400/CL 10 (2x8gb)
Geforce GTX980 4gb ddr5
SSD 850 pro 512gb
2Tb HDD WD black 7200rpm
LG Blu Ray Writer
Wifi pci-exp N900 (dual freq 2.4+5ghz)
Win7 Ult OS 64bit
FSX acceleration
2. Coordinates
Attached new pictures of the problem, taken at N 35°20.26' / W131° 40.16' + pakt
3. I run no other payware scenery than PFJ, PNW, SAK, Tonga X, I also disconnected all other freeware scenery Except RTMM.
4. I paused the flight sim several times, even up to 10 minutes, but no change.
5. I tried not on the ground, but in a plane, no improvement.
6. If you cannot help me, I'll go to Orbx. But it's sometimes tough to get the message through. Uploading a simple screenshot requires nearly a doctor's degree.
So I'd be glad if you want to take a second look...
Cheers
Marcel