Even though the Ultimate project was abandoned last year after the LevelUP got announced, a new individual developer has been “taken on board”, as Magnus Lorvik refers to it, who updated this project. The update has been announced through the Thresholdx forums.

Their newly acquired developer Jason Ariel has updated the 737-900 to work at the latest ZIBO standards. The aircraft now uses the 3.49 ZIBO systems, which are the most recent. It has been mentioned that the Ultimate 737-700 will be updated later on as well.

Among the fixes of the aircraft, we can find for example new .OBJ files, which are replacing the old 737-800 files, the name has been updated from 737-800X to 737-900U as well. Speaking of the flight dynamics and systems, the centre of gravity has been re-located as well as the docking points for cargo, fuel tanks, belly and much more.

The developer has also confirmed some bugs which can be found in the aircraft, one of them being the X-Plane 11 crash during the very first load of this updated version, and there’s only 2K version of this aircraft available.

You can download the updated rendition of this aircraft through the Thresholdx forums.


  • Updated name from 737-800X to 737-900U
  • Added the line “/updated by Jason Ariel” at the end of the .acf created by the description
  • Replaced all .OBJs that shape the 737-800 fuselage, wings, exterior lights, engines, landing gears and interior cabin with the ones from the original 739U
  • Modified the geometry of the fuselage in the flight model (FM)
  • Relocated all flying surfaces (FM)
  • Added 1.2 degrees of dihedral to the horizontal stabilizer (FM)
  • Relocated Misc Object 1 (belly) (FM)
  • Relocated CG and fuel tanks (FM)
  • Relocated docking points for cargo, rear boarding and service doors, and removed GPU and fueling docking points (FM)
  • Modified landing lights (FM)
  • Modified Spoilers and speedbrakes geometry and deflections based on real plane data (FM)
  • Relocated logo lights coordinates in the tailwinglets.OBJ
  • Changed dataref in the tailwinglets.OBJ making the rudder moving properly
  • Relocated engines and engine pylons (FM)
  • Modified Particles.OBJ to remove heavy condensation over the wings and moved the wingtip vortices from the tip of the wing to the tip of the lowered flaps (improvements still under development)
  • Relocated main gears (FM)
  • Modified OEW and MTOW to match the 737-900 (not the ER)
  • Relocated POV (subproduct of moving the CG) (FM)

Issues found so far

  • The first load of the aircraft crashes my sim, subsequent loading works fine
  • FMOD surround sounds not working properly, can hear the outside if I move forward in the cockpit (probable subproduct of moving the CG backwards)
  • Cabin windows no longer have a rain effect
  • FMC and tabled display the 737-800 model rather than -900
  • Work only done to the 2K version for now.

Author: Patrik

My aviation enthusiasm started back in March 2016 and since then I fly almost every day when I have time. I always like to discover new places or new things. The vehicles or any kind of technical things always fascinated me. As I was younger, I was also a journalist in a school magazine, so when I got an opportunity to write articles about my favorite hobby, I immediately jumped in.

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