Pitch control and indicator

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Archive88
Airman First Class
Posts: 93
Joined: 01 Mar 2016, 19:08
Location: Washington state

Pitch control and indicator

Post by Archive88 »

Can commiserate with those having trouble with the "new" AP compared with the 'old" AP in the Comanche.
Am just getting used to the Bonanza after lots of time with the Comanche.
Have a couple of questions:

The major one is: There is nothing to tell you what the trim pitch is that you are calling when you tweak the pitch selector on the AP box. Too often that ends up way too much when I arm the altitude command and I have to rapidly correct. Is there not a pitch angle or rate of climb indicator that is available? The rate of climb indicator is very slow to react.

Second: How do you set the trim pitch selector back to zero before the next flight? I've sometimes tried to take off and found the Bonanza trying to fly vertical! Do you have to set the AP to 'Disengage' before the next flight? Or does shutting down the aircraft (or shutting down FSX) reset the pitch to zero automatically?

Getting there is half the fun, and so is learning new stuff. So, not a complaint, just trying to survive the next exploratory flight in a new rig.
Thanks, -=dcp=-

alan CXA651
Senior Master Sergeant
Posts: 2438
Joined: 15 Mar 2016, 08:23

Re: Pitch control and indicator

Post by alan CXA651 »

Hi.
Look on page 93 of the manual, when triming your auto pilot you look at the VSI gauge 09 and your trim ind just above and left off gauge 22 the trim wheel.
The aircraft in level flight has a nose down att
regards alan. 8)
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Nick - A2A
A2A Captain
Posts: 13734
Joined: 06 Jun 2014, 13:06
Location: UK

Re: Pitch control and indicator

Post by Nick - A2A »

Hello dcp,
Archive88 wrote:he major one is: There is nothing to tell you what the trim pitch is that you are calling when you tweak the pitch selector on the AP box. Too often that ends up way too much when I arm the altitude command and I have to rapidly correct. Is there not a pitch angle or rate of climb indicator that is available? The rate of climb indicator is very slow to react.
The important thing to bear in mind about the KFC 200 autopilot installation we have in the Bonanza, is that the AP when engaged will always try to follow the flight director V-bar. When you first select FD mode, the V-bar will set itself to the current pitch angle of the aircraft. Thereafter when you press and hold the autopilot pitch trim rocker switch, you'll see the FD V-bar move up or down in the corresponding direction at a fixed rate for as long as you keep the switch pressed in. (Until it reaches its maximum travel that is, which I believe is 15° nose up or down.)

The exception to this is if you're already in ALT mode. If so, the rocker switch will command a constant climb or descent of 600 fpm, again for as long as you press it in.

So when it comes to engaging the AP, it'll pitch the aircraft to match where that FD V-bar currently sits. This is very different to the KAP 140 installation for example, which is a rate based autopilot and will capture the existing vertical speed.
Archive88 wrote:Second: How do you set the trim pitch selector back to zero before the next flight? I've sometimes tried to take off and found the Bonanza trying to fly vertical! Do you have to set the AP to 'Disengage' before the next flight? Or does shutting down the aircraft (or shutting down FSX) reset the pitch to zero automatically?
As Alan says, the elevator trim setting commanded by the autopilot can be seen on the trim indicator next to the trim wheel. Disengaging the autopilot and flight director won't reset the pitch trim so this should be checked before the next flight. Unlike in real life, restarting the sim or reloading the aircraft will reset the pitch trim to zero.

Also bear in mind that just disengaging the autopilot won't reset the FD V-bar. To do this, you need to disengage the FD too. A final tip: the control wheel steering (CWS) switch on the yoke will sync the FD V-bar to the aircraft's current pitch attitude.

Hope this helps,
Nick

Archive88
Airman First Class
Posts: 93
Joined: 01 Mar 2016, 19:08
Location: Washington state

Re: Pitch control and indicator

Post by Archive88 »

Ohhhh kay:
Lot's to absorb here.
First to get fully acquainted with the panel, which is still a bit terra incognita as I learn the personality of both the aircraft and its various controlling demons.
So.
Let me work on this a bit and then respond.
In any case I appreciate the response.
-=dcp=-

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Nick - A2A
A2A Captain
Posts: 13734
Joined: 06 Jun 2014, 13:06
Location: UK

Re: Pitch control and indicator

Post by Nick - A2A »

Sure thing dcp. When you've had the opportunity to spend a bit more time with the Bo's system, please let us know if you have any more questions.

Thanks,
Nick

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