Duke Autopilot? Options

[jimh]

Hi,
The Duke is my favourite twin. I've checked the KFC-225 Manual, but I've still got a question.

If I take off in a "formal" way, I set the heading bug to runway heading, arm preset altitude and VS, and switch on the autopilot on climbing out. I can then fly a flight plan by adusting the heading bug as necessary.

I'm finding, if I want to go off on a vfr sightseeing trip, when I've reached altitiude I can switch off heading hold and yaw damper while leaving the autopilot to maintain altitude, but I'm locked to the present heading.

If I want to "head off on my own", I have to disengage the autopilot, and fly completely by hand.

Is this normal, or am I misunderstanding something? I'd like to be sure I'm operating the system properly.

Regards, Jim H.

[sydwdn]

From the Duke autopilot manual

13. Heading mode (HDG) selector button.
When pressed, will engage Heading mode, which commands the aircraft to turn to and maintain the heading selected by the heading bug on the HSI. A new heading may be selected at any time [by turning the knob on the HSI] and will result in the aircraft turning to the new heading.

[ryanbatcund]

Yeah thats how I do it (OP)

[jimh]

From the Duke autopilot manual

I've read that section too. The autopilot does exactly that.

My question is: If I switch off heading hold, keep the autopilot holding altitude, switch off yaw damper, shouldn't I then be free to steer any headiing I might desire?

Perhaps I'm not explaining myself very well.

Regards, Jim

[snave]

I've read that section too. The autopilot does exactly that.

My question is: If I switch off heading hold, keep the autopilot holding altitude, switch off yaw damper, shouldn't I then be free to steer any headiing I might desire?

Perhaps I'm not explaining myself very well.

Regards, Jim

No you're explaining yourself just fine. The autopilot does NOT offer the airliner equivalent of `Control Wheel Steering`. So the modes are ROL (or wings level) and HDG (slaved to the bug). The autopilot in most GA requires a heading mode to be active to enable any other function, including Alt Hold.
Just steer the hdg bug and let the plane follow the command.

[jimh]

No you're explaining yourself just fine. The autopilot does NOT offer the airliner equivalent of `Control Wheel Steering`. So the modes are ROL (or wings level) and HDG (slaved to the bug). The autopilot in most GA requires a heading mode to be active to enable any other function, including Alt Hold.
Just steer the hdg bug and let the plane follow the command.

Thanks a lot. I just needed to know what was possible. I didn't fully understand the ROL mode. I'm quite happy with all control or no control

Regards, Jim

[Paladin]

If my memory is correct [not always so ] <CTRL> V is the wings leveller on/off, don't know if this helps on the platform specified, but maybe worth a quick try.

Maurice.

[robert young]

Thanks a lot. I just needed to know what was possible. I didn't fully understand the ROL mode. I'm quite happy with all control or no control

Regards, Jim

Hi Jim,

The ROL mode is a safety feature built in to this kind of autopilot. Its logic is that when engaging autopilot the last thing you would want would be for the wings to starting rolling or banking - after all one of the primary aims of an autopilot is to keep the aircraft in a stable attitude. Unfortunately the ROL mode also prevents manual over-ride in bank, although you can kind of over-ride it temporarily with strong aileron input, but it will always return to wings level.

Kind Regards,

Rob - RealAir

[jimh]

Hi Jim,

The ROL mode is a safety feature built in to this kind of autopilot. Its logic is that when engaging autopilot the last thing you would want would be for the wings to starting rolling or banking - after all one of the primary aims of an autopilot is to keep the aircraft in a stable attitude. Unfortunately the ROL mode also prevents manual over-ride in bank, although you can kind of over-ride it temporarily with strong aileron input, but it will always return to wings level.

Kind Regards,

Rob - RealAir

Thanks, Rob. That's exactly what I was finding. I've only ever had one hours flying in a piper apache. Any more flying was scuppered with a heart attack. There's a huge amount computer pilots like me would know if we were trained in the real world. Meanwhile we strive to fly the computer in as real fashion as possible.

I'm quite happy now I know exactly how the autopilot works. The Duke can be trimmed to fly perfectly well by hand.

Best wishes, Jim