CTD upon touchdown

[Captthud 0]

Test 3 break free

Taxied out took off flew around the flag pole a couple times landed taxied in no problems

Crashed on exit again though, this may have been caused by not shutting down Wide Server before shutting down the sim.

Faulting application name: Prepar3D.exe, version: 4.0.28.21686, time stamp: 0x594a7255
Faulting module name: api.dll, version: 4.0.28.21686, time stamp: 0x594a7300
Exception code: 0xc0000005
Fault offset: 0x00000000000155d1
Faulting process id: 0x11b4
Faulting application start time: 0x01d31a7934eb721d
Faulting application path: F:\P3Dv4\Prepar3D.exe
Faulting module path: F:\P3Dv4\api.dll
Report Id: 20834c71-8676-11e7-aadc-cc52af49c270

I have noticed 1 thing though, and I'm sure it's for another discussion

I set the engines for 1100 torque and I get 1000 torque air speeds, and 1200 torque fuel consumption

Although I haven't done the math yet

Rick

[Dick 47]

Well I had the same results as Roberto. Tried this morning and took her 3 times ( with each DLL)  to the runway on the known hotspots/airports and neither file of test 3 gave me a CTD.

Couldn't believe it so I tried again this afternoon. Same result. .. 3 times to the runway with each file and again she would not CTD..

This is test 3. So in ttl had 6 tries on one DLL and also 6 on the other and not a single CTD..

This was the first time, I guess, that I was unhappy not to get a CTD

B rdgs / Dick

=

 

[stefltt 11]

Hello,

I am not part of the testers (sorry I don't have any spare time to participate), but I would like to report another CTD tonight while backtracking the runway 30 at SBTT for takeoff. The before takeoff checklist was made. I was taxiing at idle thrust since brakes release from the ramp (medium stand). Once on the runway, I have pushed my X52 throttle forward to increase my taxi speed, then at 18 kt groudspeed I have pulled the throttle back to idle then here goes the CTD with the API.dll stuff in the window 10 events log.

So for now, the aircraft is grounded in the hangar for me until a solution is found. 

Stephane

[Bentree_ 9]

Test three test: Breakfree_Only

Win 7 P3Dv4: EHAM startup, long taxi, take-off, roundflight 15 minutes, landing, long taxi back.

No CTD.

Only problem i now already had two times is that after parking and AFE shutdown, engines 1 & 2 keep running but everything is brought down bij AFE to C&D. (Yes, all mixtures are shut of by AFE)

Tonight i will do samen testflight with the Decelaration_Only.

Kind regards,

Ben

[Bentree_ 9]

Test Three: Decel_Only

Win7 P3Dv4: Same EHAM round total off block time 30 minutes, long taxi in and out.

No CTD.

Still problem when AFE shuts down, engine 1&2 keep running and AFE status is "Awaiting settings switches" (Am i doing something wrong there?)

I will fly these two flights again in 20 hours from now.

Kind regards,

Ben

 

 

[Captthud 0]

I don't use the AFE except for, pre start, pre taxi, and pre take off. not sure what might be causing that

[Captthud 0]

One more time around the patch at KFAR with the test 3 break free to test my theory on wide server this time I shut down weather and wide server before I shut down the sim

and it worked taxied out flew around the flag pole a couple times landed and taxied back in no CTD, no crash on exit

Ran like a champ

Rick

[r_stopnicki 92]

Chris:

Your email on Test 04, arrived as I was starting the computer.

From my perspective, you can exhale.

Three tries, no CTD's.

Hopefully, that's that.

Cheers to all

Roberto

[Dick 47]

Yes, Installed test 04 and took her 4 times to different runways at my known hotspots/ airports and departed. No CTD ! Some more flying later today.

Would be great it this is solved now.

Chris: did actually find something ?

 

b rdgs / Dick

=

 

 

[Captthud 0]

TEST 4

Loaded her up, and flew from KFAR to KESC 2 hour flight

Hard landing DOH!!!

no CTD's, but it crash on exit

Faulting application name: Prepar3D.exe, version: 4.0.28.21686, time stamp: 0x594a7255
Faulting module name: api.dll, version: 4.0.28.21686, time stamp: 0x594a7300
Exception code: 0xc0000005
Fault offset: 0x00000000000155d1
Faulting process id: 0xa18
Faulting application start time: 0x01d31afc5b582e68
Faulting application path: F:\P3Dv4\Prepar3D.exe
Faulting module path: F:\P3Dv4\api.dll
Report Id: 9d2440f4-8706-11e7-b561-cc52af49c270

Same old crash we all get that one now and then

Over all it ran really good

Rick

[Adamski_NZ 942]

Sadly, I've not had enough time to do lots of flights for all these tests, so my results are far from conclusive. However *none* of the tests I tried produced CTDs - even the ones that were meant to LOL!

Test 4 (only 3 flights so far) has given me no problems of any kind. Startup, flight and final engine shut-down all worked perfectly. Neither did P3D shut down in an way inelegantly. This was using the AFE in the same way as before.

I did the usual things, plus flipping in and out of outside view (not usually recommended anyway) - all to no avail - I was able to enjoy this magnificent DC-6 no matter what I did. So ... I'm quietly optimistic! Well done, PMDG team.

Adam.

[GCBraun 2,390]

May I also get access to this build for testing? Already sent an email asking for it. Plenty of time to do some flights in the next days. Thanks!

[Adamski_NZ 942]

Just to add to my earlier post. A couple more flights with Test 04. No problems at all. Looking good!

Adam.

[cbpowell 14]

I'm delighted to hear some good news from Dick, Rick, Roberto, Adam and Mike about test 4. I'm feeling cautiously optimistic. Let's wait for a little more feedback to come in, hopefully which will confirm what we all hope.

Just to summarize, we learned that the "ground model" was the culprit. The ground model in this plane overrides Z-velocity to achieve two effects:

1. A different "ground friction / deceleration" model.
2. A better "break-free" to allow taxi at lower RPMs.

Test 4 does the following:

1. The deceleration model is inoperative / removed. We rely solely on sim friction.
2. Break-free is operative, but we limit its effect to every 1/8th of a second.

I do not comprehend why this code was breaking in P3Dv4. After all, it works perfectly well in FSX and v3. And I scrutinized the heck out of it, looking for a coding error. My best guess is that applying Z-velocity changes too rapidly causes v4 to implode; the dual decel and breakfree calcs were, for some reason, overwhelming v4 in some manner. *

That, too, is why I limited breakfree calcs to a fairly coarse resolution of 1/8th of a second. It's a bit of a hedge. I'm willing to bring that back down, once we feel confident in our newfound stability.

Regards,

Chris

* I note that I've still been unable to ever reproduce this locally. There must still be some other ingredient that I don't know yet. Whether that ingredient is a 3rd party add-on, a sound configuration, a specific sim preference, or a weight & fuel config is yet to be established.

[Adamski_NZ 942]

One thing I've not [ever] mentioned: all my flights were with 50% fuel (they've just been short hops). I'm wondering whether fuel load affects the friction calculations. I could also be why I never got a CTD when landing - being quite "light". Just a thought. I wonder if there's a "division by zero" lurking in there somewhere LOL.

Adam.