47 minutes ago, Bobsk8 said:

What a ridiculous comment. I have a copilot, two passengers in the second row, and 50% fuel.. What in the heck does that have to do with the trim wheel turning nose down about 5 degrees when the AP is disconnected.   Cheez........

Goodness.  Lighten up Bob.  First and foremost my post was not speaking to you individually. Others have reported it. And cg can have a great influence on attitude coming off AP.  Are you saying the Kodiak goes nose down?  Or that the trim wheel is changing the attitude?

Edited March 15, 20224 yr by fppilot

24 minutes ago, fppilot said:

Goodness.  Lighten up Bob.  First and foremost my post was not speaking to you individually. Others have reported it. And cg can have a great influence on attitude coming off AP.  Are you saying the Kodiak goes nose down?  Or that the trim wheel is changing the attitude?

I very clearly described exactly what is happening when the AP is disconnected on a post on this thread. The trim wheel rotates about 5 degrees nose down trim as soon as AP is switched off.  There is nothing in any normal aircraft, that would cause this to happen, if loading is in the normal range. This has been observed by people on the SWS Discord channel, and by people on this forum. If some think this is normal aircraft behavior, oh well, what can I say.   

Edited March 15, 20224 yr by Bobsk8

11 minutes ago, Bobsk8 said:

I very clearly described exactly what is happening when the AP is disconnected on a post on this thread. The trim wheel rotates about 5 degrees nose down trim as soon as AP is switched off.  There is nothing in any normal aircraft, that would cause this to happen, if loading is in the normal range. This has been observed by people on the SWS Discord channel, and by people on this forum. If some think this is normal aircraft behaviour, oh well, what can I say.   

When a head comes into contact with a brick wall...The wall will win. Lesson. Stop doing it. 😄

Just reading on the discord channel, and someone discovered that with no flaps deployed, the trim doesn't move and nose doesn't drop when disconnecting AP. He said that when he applied any flaps, he did get the trim movement and nose drop.

 

Just tried it, no flaps, disconnect AP no trim movement or nose drop.  Full flaps, nose drops and trim moves down about 5 degrees. . 

Edited March 15, 20224 yr by Bobsk8

1 hour ago, Bobsk8 said:

I very clearly described exactly what is happening when the AP is disconnected on a post on this thread. The trim wheel rotates about 5 degrees nose down trim as soon as AP is switched off.

 

"Very clearly described"?  Let's refer quickly to your three prior posts about the problem in this forum:

 

6 hours ago, Bobsk8 said:

Since the one thing I wanted the nose dropping when AP is turned off, still is not right...

 

6 hours ago, Bobsk8 said:

I just did a complete uninstall and reinstall, and it still pitches nose down when AP is disconnected.

 

3 hours ago, Bobsk8 said:

If you are on an ILS and disconnect AP at 200 feet, and the nose drops 5 degrees, that is a pretty good problem.

 

In not one of those is the word "trim" even mentioned.  You do talk about trim a bit further upthread, but given the amount of comments you've made about this one issue here it seems churlish to attack someone trying to help you for not catching that particular detail.  Looking at your recent posts I can understand why fppilot, or anyone, may think the issue related to CG.

Sometimes we may think we are communicating clearly, when in fact we are not as clear as we believe.  In these cases the fault does not lie entirely with the person who misunderstood you whilst trying to help.  I don't know one way or the other on this particular problem, but I know that that sort of attitude you're presenting here isn't very gracious, and probably doesn't make folks well inclined to help you with future problems you may have, either.

Just something to think about.

Edited March 15, 20224 yr by DeepestRed

1 hour ago, Bobsk8 said:

  Full flaps, nose drops and trim moves down about 5 degrees. . 

Which is probably working as expected - it sounds like the flaps trim compensation kicking in as the AP turns off and setting itself to whatever position it uses for full flaps ( the two are independent and trim compensation is disabled whenever AP is engaged for obvious reasons). 

If it is actually a bug it is almost certainly in the implementation of the flaps-trim compensation functionality however there is a good chance it is actually working correctly.

From the Kodiak 100 POH, page 7 -108 ...

http://www.redcliffeaeroclub.com.au/files/aircraft/Kodiak100_POH.pdf

Quote

7-27 AUTOMATIC TRIM SYSTEM
To compensate for pitch trim changes when varying flap position, an automatic trim
system is provided. The automatic trim system consists of an electric pitch trim actuator,
an airspeed switch, the flap position potentiometer, the pitch trim potentiometer, the
trim disconnect switch, and an electrical flap/trim compensation unit. This system
automatically engages the electric pitch trim servo in the appropriate direction when the
flaps are in transit. For example, when the flaps are transitioning from 20° to 10°, nose
up trim is applied automatically. Also, when the flaps are transitioning in the opposite
direction, 10° to 20°, nose-down trim is automatically applied. The automatic trim system
is active when the flaps are in transit between 5° and 35°.
The automatic trim system may be overridden by manual electrical inputs of pitch trim in
the opposite direction of the automatic trim. For example; if the automatic trim system
is trimming the aircraft nose down, and the pilot selects nose-up trim with the electric
trim switch on the control yoke, the servo will operate in the nose-up direction and will
override the automatic trim system. The automatic trim system may also be manually
overridden by grasping the trim wheel by hand.
The automatic trim system is disabled any time the autopilot system is engaged to
prevent the two systems from interfering with each other. The autopilot has its own
automatic trim system to compensate for pitch trim changes with varying flap settings.

 

Edited March 15, 20224 yr by Glenn Fitzpatrick

6 minutes ago, Glenn Fitzpatrick said:

 

Which is probably working as expected - it is just the flaps trim compensation kicking in as the AP turns off -

From the Kodiak 100 POH, page 7 -108 ...

http://www.redcliffeaeroclub.com.au/files/aircraft/Kodiak100_POH.pdf

 

well, that explains" that". 

13 minutes ago, Glenn Fitzpatrick said:

Which is probably working as expected - it is just the flaps trim compensation kicking in as the AP turns off -

Very interesting, good info!  Now I wonder why SWS never mentioned the auto trim system. I assume they intentionally programmed it.

Al

Edited March 15, 20224 yr by ark

2 minutes ago, ark said:

Very interesting, good info!  Now I wonder why SWS never mentioned the auto trim system. They programmed it, so they certainly must know about it.

Al

Programmers are usually not the same people that write the documents, things get missed.

I have no idea if they actually did implement the flaps-trim compensation or if they did, how well it is modelled and i do not have access to the game right now to test it out - but it sounds suspiciously like what is happening.

If the nose drop is "expected behavior", as per the handbook, then why is it mentioned as a fix?

Also, this question has a simple solution: asking someone, for example MBP, who has knowledge of the actual plane, whether this is "expected behavior".

 

Edited March 15, 20224 yr by Ricardo41

My Kodak not only dips the nose, but also drops a wing. Would go into a stall if not corrected.

Very hard to control with hand flying. Airilon trims seems too sensitive. Really not much fun anymore.

I think it intentionally tries to kill me...Sad 😞

 

The flap autotrim system is implemented, but why it noses down when flaps are out is weird. The code should cover all these cases. Will take another look.

 

Regarding the wing drop, what are the speed, flaps & weight when this happens? I only see three possible cases, as the FM hasn't changed:

Too slow: the P-Factor will try to roll you over. I don't think you would lose track of speed though.

Torque roll: If you push the throttles too fast (I.e. on a go-around) the plane will nose-up and roll left. You can lose control if you overdo it.

Bug: something we didn't notice while testing. Please describe on our support page/Discord to archive it.

51 minutes ago, Ricardo41 said:

If the nose drop is "expected behavior", as per the handbook, then why is it mentioned as a fix?

Also, this question has a simple solution: asking someone, for example MBP, who has knowledge of the actual plane, whether this is "expected behavior".

 

Seem to possibly be two different issues.

1. trim mismatch generically with autopilot (described as fixed)
2. trim changing when disabling AP with flaps engaged

It is not clear if they are the same issue.

It is also not clear if flaps-trim compensation is even modelled at all (easy to tell, deploy or retract flaps and see if trim changes, however I am not online to check) but if not it really should be, it is a basic feature of the aircraft outlined in the POH.

Even if flaps-trim compensation is modelled, it is not clear at all what the expected behaviour is when disabling AP with full flaps deployed. I would assume it should not do anything and trimming nose down is a bug, but actually have no idea, it MIGHT be working as expected, need to ask someone familiar with the real aircraft.

I am merely saying that trim changes connected with flap position sound suspiciously like flaps-trim compensation.

Edited March 15, 20224 yr by Glenn Fitzpatrick

Tried a few experiments:

With the AP off, lower full flaps. When I then turned the AP on, there was a strong downward pitch change.  But when I subsequently turned the AP off, there was no pitch change.

So my guess is the automatic trim/flap system is comparing what the flap setting was just before the AP was turned on to what it is when the AP is turned off. While the AP is on, the autotrim/flap setting is not active. So a likely scenario is the flaps where up when the AP was turned on (or may at the first notch), and fully down during the approach when the AP is turned off.  So what the autotrim/flap system sees is a change in the flaps and pitches the a/c down as a result. But if the flaps are fully down when the AP is turned on, and fully down when turned off, there is no pitch change since the autotrim/flap system does not see a change in the flap setting from before the AP was turned on to after the AP was turned off.  The autotrim/flap system only reacts to changes "it sees" in the flaps.  Or so I think.  🤔

Of course this all assumes SWS actually implemented some form of the autotrim/flap system.

Al

Edited March 15, 20224 yr by ark

4 hours ago, Beagle12 said:

I think it intentionally tries to kill me...Sad 😞

 

lol,  i wouldn't go that far😊 in the meantime, until its fixed keep your nose down, chin up, and dont get in a flap😁

Edited March 15, 20224 yr by icewater5