Autopilot Tutorials?

[BenKorek2021 23]

I'm just getting started flying the Aerosoft Twin Otter (despite having bought it on the day it was released). As a result, I think I'm a bit behind on the learning curve relative to most people here. So my question is this: Are there tutorials laying around here somewhere? I see mentions here on this forum of videos, but no links?

 

I flew it on a short flight this evening and the autopilot doesn't make any sense to me:

 

1. I don't seem to be able to fly it in heading mode only? As soon as I engage it in Hdg mode, even with Alt and VS buttons off, it wants to control my altitude? How do I turn off the altitude control while leaving the heading control engaged?

 

2. Vertical guidance seems random to me? Sometimes, engaging Alt mode for a descent causes the aircraft to dive at greater than 2000 ft/min, while other times it doesn't descend at all? I've seen a video and a comment that says you need to press the VS button after selecting Alt and then press the up/down buttons on the RHS of the autopilot, but that doesn't seem to work reliably? Sometimes the LCD displays the VS and the values change by 100 foot increments with each button press when you do that, while other times it doesn't? (The times it has dived me towards the ground at greater than 2000 fpm, I couldn't get it to show the VS option.)

 

I must be doing something wrong? Any help would be appreciated.

 

P.S.

 

I am running version 1.0.5 of the Twin Otter.

 

 

[MarkHurst 173]

27 minutes ago, BenKorek2021 said:

1. I don't seem to be able to fly it in heading mode only? As soon as I engage it in Hdg mode, even with Alt and VS buttons off, it wants to control my altitude? How do I turn off the altitude control while leaving the heading control engaged?

 

2. Vertical guidance seems random to me? Sometimes, engaging Alt mode for a descent causes the aircraft to dive at greater than 2000 ft/min, while other times it doesn't descend at all? I've seen a video and a comment that says you need to press the VS button after selecting Alt and then press the up/down buttons on the RHS of the autopilot, but that doesn't seem to work reliably? Sometimes the LCD displays the VS and the values change by 100 foot increments with each button press when you do that, while other times it doesn't? (The times it has dived me towards the ground at greater than 2000 fpm, I couldn't get it to show the VS option.)

 

There is a full manual here. Some of the features are not implemented in MSFS. Most notably, the VS capture when selecting AP on doesn't work, it always sets the VS to zero. This is probably what your point (1) is noticing. I did some programming to fix this, which I made a video about. There is no VS button; the ALT button toggles between ALT and VS modes. When in VS mode, pressing the up/down buttons changes the display to show the selected VS, but it only stays visible for a few seconds, then it reverts to showing the preselected ALT. When in ALT mode, the up/down buttons are supposed to nudge the held altitude but that doesn't work properly. I can't explain your uncommanded dives, but others have described something similar so maybe there are bugs too.

[Aerosoft Team [Inactive Account] 51558]

And always keep in mind that in real life most Twotter pilots simply do not use these outdated systems and fly it manually. 

[mhron 31]

Yes but there are usually two pilots in the real life cockpit and for me the AP is the best way how to enjoy the MSFS scenery.

[BenKorek2021 23]

On 3/28/2022 at 11:33 PM, MarkHurst said:

 

There is a full manual here. Some of the features are not implemented in MSFS. Most notably, the VS capture when selecting AP on doesn't work, it always sets the VS to zero. This is probably what your point (1) is noticing. I did some programming to fix this, which I made a video about. There is no VS button; the ALT button toggles between ALT and VS modes. When in VS mode, pressing the up/down buttons changes the display to show the selected VS, but it only stays visible for a few seconds, then it reverts to showing the preselected ALT. When in ALT mode, the up/down buttons are supposed to nudge the held altitude but that doesn't work properly. I can't explain your uncommanded dives, but others have described something similar so maybe there are bugs too.

 

OK. Thanks. I will have a look at the manual. I'm hoping that there's a way to configure it so that, for example, it will hold an altitude while I manually fly a heading (or that it holds a heading while I manually fly the altitude). I think I've got much of the rest of it worked out, but I haven't figured out how to configure it so that it only does one or the other function. (And if they're always coupled, what's the point of having separate buttons for the altitude hold and heading hold functions?)

 

But you mention that you made a video... Can you please share the link?

 

On 3/29/2022 at 9:34 AM, Mathijs Kok said:

And always keep in mind that in real life most Twotter pilots simply do not use these outdated systems and fly it manually. 

 

Sure. But on a longer flight it is nice to have. I just flew C-GKCJ across the Rockies and having it eased my workload. (Air Inuit took delivery of it used from Viking in CYYJ and I am delivering it to Quebec for them . I'll be delivering the others to their new owners in their respective locales once I finish C-GKCJ's delivery. I'm not ashamed to admit that I'll be using the autopilot for a lot of that flying.)

[BenKorek2021 23]

@Mathijs Kok: Actually, there seems to be a bug... @MarkHurst said above that there's no vertical speed button on the KAP140 autopilot in the Twin Otter, but then why do we get the "tool tip text" in the image below when we hover the mouse over the "Arm" button. I didn't pay close attention to the text on that button so I missed that it says "Arm". I assumed it was a vertical speed button based on the "tool tip text".

 

Please login to display this image.

 

[MarkHurst 173]

2 hours ago, BenKorek2021 said:

OK. Thanks. I will have a look at the manual. I'm hoping that there's a way to configure it so that, for example, it will hold an altitude while I manually fly a heading (or that it holds a heading while I manually fly the altitude). I think I've got much of the rest of it worked out, but I haven't figured out how to configure it so that it only does one or the other function. (And if they're always coupled, what's the point of having separate buttons for the altitude hold and heading hold functions?)

 

You cannot fly manually if the AP is engaged, it always controls a lateral and a vertical mode at the same time. The buttons allow you to switch between which modes are in use. I did share my video here but apparently it wasn't allowed. If you click the banner in my signature you will easily find it.

 

[BenKorek2021 23]

6 hours ago, MarkHurst said:

 

You cannot fly manually if the AP is engaged, it always controls a lateral and a vertical mode at the same time. The buttons allow you to switch between which modes are in use. I did share my video here but apparently it wasn't allowed. If you click the banner in my signature you will easily find it.

 

 

Yeah, reading the KAP140 manual that you provided the link to, it seems that both axes are always under autopilot control when it is on, it's just down to where it gets its references from (e.g. heading, GPS nav data, altimeter, VSI, whatever).

 

I guess it is the same autopilot in all the MSFS aircraft, but this Twin Otter is the first aircraft that I've flow in the game that actually has an autopilot in it. I usually prefer to fly simpler aircraft, but I'm attracted to the Twin Otter because it is still a bush plane at heart... A very capable one, but still a bush plane.

 

EDIT:

 

Thank you very much @MarkHurst!  I found your video and followed along with what you did and now my autopilot is a lot more sane. I think I may even be able to solve my ADF tuning problem with what I've learned from you about Spad.next.