Machalot

I have always struggled with low drag PLAN bombing for this exact reason. I get the right altitude and speed, line up the pipper on the target, hit UNSAFE, and the pipper instantly drops to the bottom of the HUD and disappears right after that. I see people do it successfully on Youtube, but I have never been able to figure out what they are dong differently. I switched to using DYK almost exclusively, which works as advertised, but exposes me to SAMs and AAA more than I would like.

Yep, just noticed this yesterday.

Ok, then my remaining question is whether Tacview AoA is trustworthy. Later on I'll try to find the original post that was the source of my doubts. Update: Couldn't find it. The gist was that a guy and his wingman were flying in close formation pulling the same g's with vastly different AoA in Tacview. When he asked about it in the forums, people told him Tacview AoA can be unreliable based on the way track files are constructed.

You seem to have missed my point. The G value measured by the aircraft Z accelerometer will include 95% of the lift and 31% of the drag currently on the airframe. It's a change of coordinates to compare CL and Nz that must include the drag component.

But the 31% contribution of drag might.

I'm not trying to be testy here, although apparently this thread is heading that direction. I'll take a look at things you calculate and post, but I'm not interested in trying to pull and calculate my own results from your video. One other thing to consider is whether you are calculating and measuring the same acceleration quantity, i.e. wind-fixed vs body-fixed Nz. As I'm sure you know, the trig says at 18 deg AoA there is a 5% knockdown of lift and a 31% contribution from drag into body-fixed Nz. Do you know if the G value shown in Tacview is body-fixed or wind-fixed?

You go from steady 2.8 deg AoA to ~17 deg and then steady ~19 deg in less than a second at 14:55:52. Hard to know if that's realistic. The bigger issue is that the sample frame you chose, ~17 deg, is at the tail end of the transient so the jet still has a lot of alpha rate, and the FCS hasn't deflected the surfaces to arrest that rate yet, or is in the middle of doing so, so they are likely not in a trim configuration.

Can you tell me what timestamp in that 22 minute video?

I thought I read somewhere that Tacview is not a reliable source of AoA. Did you get it from Tacview or in game? Also make sure it's degrees and not "AoA units". Also note that the charts you posted are likely for quasi-steady state maneuvers with control surfaces trimmed, whereas you are looking at a transient flight condition to make your calculations. In my experience that can make a huge difference because the control surfaces are not trimmed.

HB has acknowledged this and is working with ED to fix it. https://forums.eagle.ru/topic/267824-27-viggen-patch-14-04-2021-feedback-thread/?do=findComment&comment=4629085

Why are they initially turned off when starting at night, but not day?

Is the crash related to user-created map points, or any map points? I get CTD when I spawn into the Viggen on the Hoggit servers. There are tons of script-created map points for the overall mission, but I did not create any Viggen map points that could have caused the crash.

I can also confirm Hoggit Georgia and Hoggit Persian Gulf crash when spawning in the Viggen, while Aerobatics Online Caucasus works.

The damage could be wing root fatigue, which shortens the service life; or cracking/yielding at stress points, which requires servicing to disassemble and possibly replace structural components.

Fair enough. Just depends where you choose to draw that boundary.

One of the generic sim updates was " This might affect the Hornet TDC. Several people in these forums have had problems designating targets in the Viper and Hornet due to barely perceptible noise in their input axes. They fixed it by adding a little deadzone to the TDC slew axes. See if a deadzone brings your diamond back.

Just curious, are the drag coefficients not considered part of the flight model? If not, then what does "flight model" include, because I have been thinking of it wrong.

I would bet money this is an error in the code that initializes the aircraft's longitude or heading. That negative number is an angle in radians equal to about 16 degrees after unwrapping the full circle. Does that match any figures in the mission?

Glad I could help!

Often when I dim the HUD a little too much and want to turn it back a little brighter, any motion of the knob in either direction will continue to make it darker until it disappears. Only after the HUD is completely blank will the the brightness begin to increase again as I turn the knob in the bright direction. This also seems to happen on the bright end, where the HUD will continue to get brighter no matter which way I turn the wheel, until it reaches maximum brightness, at which point it will get dimmer again. I observe this issue when using the mouse click-and-drag, and when using the scroll wheel. It's not universal, because sometimes it does behave as expected (I think in the middle of the range). Does anyone else notice this?

Wind above 5 kts is required for ILS?

But it makes it much harder to attack the base of the pylons.

Just saw the same bug report over in the Viper forum.

I had problems very similar to what you describe if the Comms menu is open while I turn the HUD brightness wheel on. The Comms menu somehow prevents the mouse button from releasing, so any subsequent movement of the mouse continues to rotate the wheel, and often it rotates right back down to the off position. I learned to always close the Comms menu before clicking anything in the cockpit.

I just flew the Viggen anti-shipping quick action mission in the Persian Gulf. It has some awesome weather with heavy clouds and intermittent rain. It requires you to make good use of the TILS to land at Khasab on runway 19 in near zero visibility almost to the deck. However, I couldn't get Khasab ATC to turn on the runway lights for me to help me pick up the runway visually. Is there a way to get daytime runway lights, or is it just not possible? (As an aside, I also couldn't get the AI ATC to move past the initial approach vector. After flying that vector, there was never an update with approach information nor a comms menu option to request landing clearance. Maybe a state problem related to the lights issue?)