F-35 Alpha test Work-in-progress post

Below is a list of issues either known or found in the Alpha build as released to testers yesterday night. This list includes only the "accepted" issues - i.e. things that I acknowledge as actual defects (if compared towards the scope of the project). I will keep this list updated, as reference for me, for the testers and also for anyone interested in the project progress.

Note to testers: no need to rush - I won't have much time until the next weekend. While evaluating the flight model, please keep in mind the fact that the aircraft is loaded with two JDAMs.

UPDATED 23-01-2010

External model

1) Nozzle animation incorrect.
Action: redo animation sequence. Evaluate link to nozzle animation variable of FSX:Acceleration (SP2 compatibility?) or link to rpm for smoother animation - DONE in model build 43
Status:closed - solution approved for Beta - animation sequence redone. Still linked to throttle but closer to the actual behaviour.

2) Jaggies nearby the engine intake aera. Visible on close inspection only, partially due to geometry/smoothing, partially due to self-shadowing algorithm.
Action: evaluate mitigation by local application of Meshsmooth command. It may be impossible to fix completely - but will not be noticeable by most users.
NOTE: Upper to lower side discontinuity verified correct. Minor issue spotted with intake bulge curvature. Inspection highighted UVW misplacement in the engine intake area
Status:open - high priority

3) Excessive gap between engine nozzle and fuselage.
Action: check against photos and eventually modify the mesh.
Status:CLOSED - fixed on model buidl 46

4) Afterburner effect/1: effect poking through A/C fuselage. NOTE: FSX effects positioning an visibility is somewhat dependent on graphic card model and setting. Having the card set in "performance" mode makes things worse. E.g.not perceiveable on my system.
Action: modify .fx file (shrink them a little - check nominal position)
Status: open

5) Afterburner effect/2: flame should be much longer in stage 3. NOTE: a/b flame is confined into the engine nozzle on purpose for F-35B preparation. Also, my experience with "big" flames is not really positive (different users had different results).
Action: evaluate modification in .fx file. Stage 1 effect seems correct if compared to F-35 a/b videos.
Status: open

6) Wheel/tires animation incorrect. Status: CLOSED (Fixed dynamic modle for tires, diameters were wrong)

7) Navigation lights missing. Note: they were left out as all the F-35AA-1 pics I have are showing only anticollision lights. Status: CLOSED (Nav lights placed into the lights subassembly)

8) Covers for auxiliary air intakes missing when using SHIFT+E+4 command. Note: never seen such covers in any picture. Status: CLOSED (Auxiliary inlet cover modeled - but no ribbons as I'm saving polys for the weapons ).

9) Irregular bumps in the external model. Action: modify the extenal model. Sratus DONE: (model build 44) Auxiliary air intake untouched, other bumps geometry modified and new textures.

10) Poor detail in the refuel receptacle. Action: While the comment is correct, I do not have pictures clear enough to make a porper model - Edit: will model a stardard receptacle based on similar devices. Status: CLOSED. Refuel receptacle modeled in build 46

11) Poor detail in the nose landing gear. Action: Increase detail in the 3d model. Status: CLOSED - Mitigated issues with additional gear detail, previously missing.

12) Modeling mistakes in the main gear. Action: evaluate complete redo of the kinematism. Status: Closed on model build 45 - Redone most parts of the main gear and applied new textures.

13) AIM-120 not attached to hardpoints. Action: will model LAU-147 (although not actually mounted in AA-1). Status: CLOSED modeled hardpoints for AA-1 will model LAU-147 for operative model

14) Nose gear door detail/accuracy not good enough. Action: impossible to modify the shape, but will redo the hinges and add the actuator. NOTE: Applies only to AA-1 model - other models have a different door (2 parts). Status: Closed (model build 45 - Redesigned hinge and added actuator and new texture)

15) Request to model the lights in more detail. Action: modify the model. Note: initial evaluation shows that boolean operation is requested: such operation will inhibit model roll-back. Status: CLOSED (No additional modeling, but better texture)

Miscellaneous other actions (not requested by testers):

- Resize main gear wheels / tires - DONE

- Add detail to the main fuselage texture diffuse/spec/bump - DONE

- Evaluate changes in texture brightness /contrast - DONE, also miscellaneous enhancements to AA-1 texture coloring. Note: experiments with primer-only AF-1 texture looking good.

- Fix mistake in texture UVW in the inner side

- Add separate moving part for weapon door hinge - visible on real plane on closer inspection, not modeled DONE

- A/c is sitting rather low on the main gear. Changes to the animation sequence and contact points needed. FIXED

Virtual cockpit

1) Virtual cockpit frame rate low / excessive number of polygons.
Action: optimize virtual cockpit model mainly by removing some of the parts of the external model attached for track IR users (eg. lower surfaces fuselage, flaperons, tails). Evaluate reduction of invisble polys/faces. NOTE: Only one tester has highlighted this issue. Performance seems on par with similar products for the others.
Status: open

2) Temporary HUD useability (keeping this open in case the new HUD/HMD is not available on time)
- Proposal to reduce the size of the 3D part
- Enlarge the G meter text window
- Enlarge various text windows in 2D panel

CLOSED / NEW HUD IMPLEMENTED AND AUTHORIZED

3) Minor texturing UWV misplacement on cockpit floor.
Action: fix mapping in .mdl file. DONE in VC build 19
Status: CLOSED

4) VC night lighting too bright.
Action: dim the brightness in .fx files.
Status: CLOSED - modified .fx file

5) Incorrect tooltip showing "parking brake" in the battery area.
Action: check .XML embedded in the .mdl. DONE in VC model build 19
Status: CLOSED

6) Miscellaneous autopilot interface:
- Autopilot master hotspot not working. NOTE: A/P master will be part of the FCS panel
- Autothrottle miscellaneous issues. NOTE: At first check it .XML appears correct. I had similar issues in the tomcat.
- Autopilot max bank activation. NOTE: Presence of this command is a mistake and will be removed.
Action: check associated .XML
Status: open

7) Engine needles behaviour not correct
Action: check associated .XML
Status: CLOSED. COMPLETELY NEW GAUGE

8) Visual hole aboce the pedals (polygons missing); Action: modify the Vc model (add a cap) Status: CLOSED (VC model build 20)

9) "No Hold" texture stretched above ejection seat; Action: modify the Vc model / texture; Status: CLOSED (VC build 23)

10) "patches" on the side of the Vc glass are unconnected to the canopy; Action: modify the Vc model; Status: Unclear how the thing should look like. CLOSED for now.

11) Explosivc cord not connected to glass; Action: pending evaluation - this was intentional to prevent clipping that happened during initial tests; Status: Closed with no action - Current geometry prevents clipping. Leave as is.

12) Stick movement excessive if compared to real F-35 stick. Action: modify animation sequence. Status: closed (VC model build 20 movement reduced, still not as little as the real one but provides a "visual feedback" that enhances the experience IHMO).

NOTE: Track IR testing generally good. No major issues, apart from the "usual" seat clipping and minor flaws in extreme conditions.


Flight model

1) Excessive top speed. Top speed in excess of 2.05 Mach. Real plane rated 1.6 to 1.8 (varying according to sources).
Action: change the wave drag table in the .air file - DONE
Status: CLOSED - approved for Beta. New wave drag / Mach table makes it extremely difficult to exceed Mach 1.69

2) Weak brakes. Brakes cannot hold the plane still even at relatively low RPMs.
Action:modify brake effectiveness either in the .air or .cfg file - DONE
Status: closed - promoted to beta. The brakes are now strong enough to keep the plane still up to almost full military power. However, brakes seem excessively strong when stopping the plane after landing.

3) A/c prone to yaw instability during takeoff run. NOTE:Verified only with crosswind.
Action: root cause unknown. Check for asymmetric loads. Possibly increase yaw stability/MOI or adjust scalars.
Status: Modified values in the air file parameter. Symmetric load checked and correct. Still happening with significant crosswind (15 kts or above). Should be manageable by most pilots. Awaiting flight test to close. CLOSED. LEFT AS IS FOR BETA TESTING

4) Micro-oscillations while on ground. Probably due to contact points instability.
Action:modify contact points parameters in the .cfg file. NOTE: was not present in earlier build (with incorrect auxiliary contact points) DONE in latest aircraft.cfg
Status: CLOSED

5) Pitch changes depending on throttle setting. FCC/FCS should compensate such effects in the real plane. Effect seems related to center-of-lft vs. center-of-weight misalignment, as proper .air files parameter seem correct.
Action: Check .air and modify a/c balance in order to minimize such effect. NOTE: for FCC/FCS emulation, it may desireable to set to 0 all the secondary effects of aerodynamic surfaces.
UPDATE: All fore/aft loads artificially balanced towards the aerodyamic center. Load is now balanced versus pitch. This is not theoretically correct, but makes up for the FCC/FCS absence. Issue seem mitigated to the point of being acceptable for the vast majority of the users. UPDATE: I forgot to to balance the engine pitch momentum - my bad, thanks Robby.

Status closed: Behaviour balanced in most situations.

6) Pitch changes when activating virtual speedbrake. FCC/FCS should compensate such effects. See 5) - it is probably the same issue.
Action: See 5
Status: Closed. Not completely solved but definitely acceptable.

7) Low roll rate. User report low roll rate for a fighter. NOTE: it is unclear what the actual roll rate should be. Current roll rate seems realistic for a plane with 2 JDAMs and 2 slammers, but may be less agile than real F-16,
Action: Aileron action enhanced by 10% - but awaiting further evaluation and feedback.
Status: CLOSED on latest fligh model - enhanced ailerons effects and travel. As a good side effect, a/c is more maneuverable at low speeds.

8) Excessive loss of energy during high-G turns. Action: unclear what the target should be for this plane in the depicted configuration. Assuming 5 - 6 g sustainable turn. Will see what I can do. Status: CLOSED with thanks to Roberto Leonardo

9) High AoA dynamics causes excessively low stall speed (75kts). Action: TBD some users are happy with the high AoA dynamics, as in line with some claims by LM. Will evaluate minor changes. Status: open - unclear if it is better to leave it as is. CLOSED. LEFT AS IS FOR BETA TESTING

10) Check landing attitude AoA (approach at 140kts?). Action: TBD - The only information I have is about X-35 whose appoaches were conducted at rather high speeds (155/165 kts). NOTE: Most users report the landing behaviour is good. Status: open - unclear if any action is needed. CLOSED. LEFT AS IS FOR BETA TESTING

11) Full flap deployment happens at low speed. Action: TBD - flap is controlled by FSX via the maneuvering flap option. Check if it possible to modify the speeds, otherwise no action. Status: open. CLOSED. LEFT AS IS FOR BETA TESTING

12) Virtual speedbrakes not much effective. Action: easy fix to the .air file. Status: CLOSED - Boosted speedbrakes effect

APPENDIX A: LIST OF MISSING (BUT PLANNED) FEATURES IN THE VC

- ICAWS (currently not working at all)
- FCS window to include touch screen functions for flaps/brakes/trim/autopilot master switch (note: this may not be realistic as those are typical HOTAS functions...still may have some use for FSX)
- FCS window will show more information
- Context sensitive weapon window pop-up (with no actual functionality)
- Touch screen radio window within the MFD
- Context sensitive HUD backup window within the MFD
- Fuel receptacle/weapon bay opening activation via touchscreen (currently implemented but not working due to an unidentfied bug...)

APPENDIX B: LIST OF OTHER MISSING (BUT PLANNED) FEATURES

1) AF-1 vsual model:
- new two piece nose landing gear doors
- new APU exhaust location
- new probes
- jagged fuselage/nozzle interface
- weapon bay: undecided between real and mock JDAM
Livery: still undecided between official artwork or actual primer-only appearance

2) Production F-35 model - same as above but:

- Removal of the nose probe
- EOTS
Livery: Most probably USAF 58th FS "Mighty Gorillas", which I understand is the first confirmed unit to receive F-35s.

3) Generic F-35 model for repaint

APPENDIX C: LIST OF NICE-TO-HAVE FEATURES (NOT PLANNED)

1) F-35A Thunderbirds (according to promotional LM artwork).NOTE: would require a special flight/visual model (with no weapons)

2) F-35A with external loads

3) F-35B STOVL version. Would require a lot of work to modify the visual model. Also, it would have the "superflaps" flight model.I know it is pretty lame but STOVL dynamics is not natively implemented in FSX... FSUIPC.dll methods exist but I do not want the model to be dependant on external modules

4) F-35C Would require a lot of work to modify the visual model and extensive flight test for carrier trials.

5) Custom sounds - I know it would be nice...

Color key:
Green - issue solved, or mitigated to the point is acceptable or not perceived by most users
Yellow -issue open, and could be perceived as product defect by many users. Awaiting action or investigation. Or issue open, mitigated to the best of my knowledge but will still be perceived as defect by users. Or issue open but appears easy to fix.
Red - root cause not identified as of today. Or the problem is beyond my knowledge or impossible or difficult to solve.