fixed [REPORTED]"Phantom" Steerpoint 1

Cold Start and Full Alignment at Incirlik

Entered Bassar Al-Assad as SP1 while the jet was warming up.

Departed Incirlik and engaged autopilot to steer to SP1

While en route to SP1, entered Allepo as SP2

(The jet wandered a little as I banged in the LAT/LON for SP2 but settled back on course to SP1 after I was done with data entry)

Now at this point, I disco'ed the autopilot to double check the steering to Aleppo and when I came back to SP1, I realized I was already right on top of the airbase at Bassar Al-Assad.

The jet had been tracking a point well to the south.

Like down by Haifa.

It had not been tracking the location of the steerpoint I had created on the ground back at Incirlik.

Unfortunately it won't let me upload the track.

Further research reveals that the coordinates you put into Steerpoint 1 do not take unless you jog the Steerpoint Rocker UP to 127 and then back DOWN to 1.

Tested on all four maps and found the following:

Cold Start Vaziani

Enter Coords for Beslan during warmup

Beslan is 340 for 97nm

Jet steered 283 for a point 516nm away

Cold Start Nellis

Enter Coords for Creech TACAN during warmup

Creech Tacan is roughly 302/37

Jet steered 350 for a point 215nm away

Cold Start Al Dhafra

Enter Coords for Al Ain during warmup

Al Ain is 090/58

Jet wanted to go 038/147

Cold Start Incirlik

Enter Coords for Basser Al-Assad during warmup

BAA is roughly 168/99

Jet wanted to go 165/121

(And this syncs with what I posted first about wanting to go farther south than the intended destination)

Now, if this is correct behavior, it needs to be documented as such so people know to jog the steerpoint rocker as part of their pre-taxi or pre-takeoff checklist.

F-16 INS bug calculating distance to steerpoint

The F-16 INS has a large error when calculating the distance and heading to the next waypoint.

To produce this error I am entering a waypoint manually via the ICP. I am pulling the lat/lon coords off my kneeboard. I know they are correct by verifying with the F10 map. I know my INS is properly aligned because it reports my current position as verified by the F10 map. Typical cases I've seen are 446 nmi from Mineralnye-Vody to Krasnodar, and 482 nmi from Mineralnye-Vody to Novorossiysk. Measurements on the F10 map put those in the range of 220-230 nmi. The steering cue on the HUD was also way off in the wrong direction, as if pointing to some far-off steerpoint. When I was attempting to navigate to a steerpoint I had set at Novorossiysk, and I was northeast of Novorossiysk according to the F10 map, it was telling me to fly straight west.

I saw the issue twice tonight. The second time I had my steerpoint set to Novorossiysk and actually landed there and parked. I was probably parked within 1 nmi of my steerpoint but the HUD reported 152 nmi away. The follow screenshots show my DED and HUD, first in INS mode to show that the INS was properly navigating, and second with the DED showing my steerpoint. The lat/lon are nearly the same (N 44.39/44.40, E 037.46) but the HUD reports a huge distance of 152 nmi to steerpoint 2.

(I took these screenies in VR not realizing they would come out so grainy -- they were very readable in game. I will take better screenshots and a track this weekend.)

I have a dxdiag.txt file I will happily provide via a non-public means.

Rig:

DCS Open Beta 2.5.6.53756

Windows 10 Home 64-bit, Version 2004

32 MB RAM, 250 GB SSD

AMD Ryzen 5 1400 Quad Core at 3.2 GHz, overclocked to 3.7 GHz

NVIDIA RTX 2070 Super

Oculus Rift

I think we found the same issue...

https://forums.eagle.ru/showthread.php?p=4461908#post4461908

I just did a single player test to record a track for my related thread, using the Instant Action hot start at Guadata and setting a manual waypoint for Novorossiysk, approx 154 nmi away at heading 303.

I found that immediately after I hit ENTER after typing in the first piece of steerpoint data, whether it was LAT or LON, the incorrect distance and heading were displayed on the HSI as 298 nmi at heading 295 (and incorrect distance 298 on HUD). Typing in the rest of the steerpoint data had no effect on the displayed values. In this case the jet came preloaded with steerpoints 1-6 so I was entering data in slots 7 and 8.

However, if I clicked the steerpoint rocker up or down one click and then returned, it would then show the correct distance and heading on the HSI and HUD. I did not have to go all the way to 127.

Related thread: https://forums.eagle.ru/showthread.php?t=284000

Just ran a test on the Aerobatics Online (Open Beta) multiplayer server, which is where I first encountered the issue. I spawned in a Refuel or Die F-16, set the autopilot to hold course, and entered steerpoint 2 manually to Kobuleti. The computed distance and bearing were way off.

Here's the overview map. It shows I'm ~266 nmi from Kobuleti on a bearing of 195. (I'm not flying at 195 but that's the direction to Kob.)

But when I start to enter the steerpoint, it calculates the wrong distance and bearing based on just the LAT data.

After all data is entered, it doesn't update the calculation, it still just shows the wrong data.

But after clicking the steerpoint rocker down to 1 and then back to 2, it calculates roughly the right distance, but the bearing shown on the HSI is 152, which is off by ~40 deg from 195 on the overview map.

The trk file is 8 MB so I can't upload it but would be happy to provide it by some other means.

I’m aware it can be corrected by rockering up to 127 and back down to 1

I just want to know if this is a bug or a feature. ?

In another scenario I tried, it was not corrected, the bearing was still wrong. Although I didn't go all the way to 127. That would be a silly feature.

In another scenario I tried, it was not corrected, the bearing was still wrong. Although I didn't go all the way to 127. That would be a silly feature.

You only need to go up (down?) to 127 from 1 and back again.

But I won’t hesitate to swing check my entire flightplan with my wingman, and I’ll swing check SP1 twice from two directions on the rocker.

Ok, I tried that and it does seem to force a recompute of the bearing as well, so it shows up correct. That's at least a functional workaround. But I would be amazed if that is a true feature of the jet.

Yeah I’m thinking it’s not.

I'm getting another issue where my magnetic compass is off anywhere beteen 20-50 degrees compared to the THDG value in the INS and compare to the F10 map. Have you seen anything like that?

I'm getting another issue where my magnetic compass is off anywhere beteen 20-50 degrees compared to the THDG value in the INS and compare to the F10 map. Have you seen anything like that?

Hadn’t noticed but I’ll try to remember to look.

Hi Bignewy, I have an 8 MB trk file but it's still over the size limit. Is there another means to upload it for you?

I’ll see if the jet still does it on a Stored Heading alignment. That might keep it short enough to get an acceptable track size.

Really though, this one should be very simple to reproduce.

- Put in LAT/LON for a destination while the jet is warming up.

- Take off and engage Autopilot for SP1 (without touching the SP Rocker at all)

- Jet will head towards a point that’s not in the direction of your intended destination nor the proper distance.

For the details on this track, reference "Cold Start From Nellis" posted above.

I did the exact same steps and the jet did the exact same thing. It headed 350 degrees to a point 215nm away UNTIL I jogged the SP Rocker down to 127 and back to 1.

Then the jet turns toward Creech.

Phantom Steerpoint.trk

One further point: You don't even have to take off.

If you put the HSI in NAV, you'll see that the Course Needle is not pointing toward Creech, it's pointing to 350 and the DME says 215nm

Confirm. There's nothing special about steerpoint 1 or before/during/after align. Any edits of the STPT page coordinates do not take effect until that steerpoint is reselected. I cannot find a situation where I edit steerpoint X on the STPT page and see a change immediately after pressing ICP ENTR.

Confirm. There's nothing special about steerpoint 1 or before/during/after align. Any edits of the STPT page coordinates do not take effect until that steerpoint is reselected. I cannot find a situation where I edit steerpoint X on the STPT page and see a change immediately after pressing ICP ENTR.

I actually see the change to the steerpoint take effect after the first piece of data is entered, which gives a spurious result, but it does not update after additional fields are entered.

More Strangeness...

Cold Start Incirlik .. Full Alignment

Enter LAT/LON for Basser Al-Assad during warmup

Once warmup was done, I racked the SP Rocker down to 127 and back to 1

(Jet navigated to BAA just fine so the "workaround" worked)

En Route to BAA, I entered the LAT/LON for Incirlik RWY 23 so I could navigate back to base.

Now play along with the pictures please:

LAT/LON For The Numbers At Incirlik RWY 23

HSD Displaying My Two Steerpoints

TACAN (21X) Heading Matches Heading and Distance shown on HSD

But This Is What The NAV System Showed

And Note: "Phantom Steerpoint 2" was not the same place that the original Phantom Steerpoint 1 took me the first time I encountered this oddity...

Emmy, did you happen to check whether there was agreement between the following heading indicators:

-Magnetic compass

-HUD heading tape

-HSI

-DED INS screen THDG indication

-F10 map actual heading

I have found these to be inconsistent with each other by anywhere between 20 and 180 deg. Usually in the 30-45 range. Sometimes the TACAN is physically correct even though it points to the wrong number on the HSI.

Rats, I forgot to cross check all of them. My bad...

Ok, so having to "wake up" the system by jogging the SP Rocker aside, could these anomalies be related to working in EAST LON in Syria and not WEST LON?

I just flew for about an hour on our NTTR Server and I waited until I'd reached my CP before I put in my TGT coordinates but when I changed the SP to my TGT, the entire system slaved right to where it should have for a CCRP GBU-12 drop and then when I went back to the SPs for my flightplan, everything behaved as it should.

Oh, and @Machalot, everything seemed to line up ok on the NTTR...

Haven't checked Syria yet.

Further musings while waiting for word from on high...

Slightly different situation tonight but still Syria in SP

- Hot Ramp Start at Ramat-David with six pre-placed steerpoints.

- Jet navigated fine to all (and did not need to jog the SP Rocker)

- Added a SP7 to go to Incirlik and while the TACAN showed my destination was over 200nm at about 355 degrees, the NAV System was taking me 014 degrees and only about half the distance.

- So, I made a SP8 and put the same LAT/LON in that I had used for SP7 with no change to the bearing and distance I was flying.

- HOWEVER, decrementing back down to SP7 suddenly gave me the CORRECT heading and distance to fly.

I think in this case, it was the same issue related to having to jog the SP Rocker for a self-entered SP1. The Jet saw my SP7 in the same vein it would see SP1 had it been self-entered. Moving the SP Rocker made SP7 suddenly valid...

It also means that SPs laid out in the ME are essentially irrelevant to the jet’s nav system. Players flying on servers where routes or targets are already laid out would never encounter the need to jog the SP Rocker.