How does the auto pilot know that the plane is right-side up?

I cringe a little anytime I see that I have gone posting things again.
 
MauleSkinner said:
According to the current Instrument Flying Handbook, it has an "erection mechanism". Some of the older versions were more descriptive.:rolleyes:
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Got it...

Now I know how it knows which way is Up!!

Thanks.
 
Aren't most modern autopilots that are integrated with glass displays using AHRS instead of gyros?
 
Sac Arrow said:
Aren't most modern autopilots that are integrated with glass displays using AHRS instead of gyros?
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It depends, but for the most part I think not. I'd imagine the new Garmin ones and the experimental ones do, but not so much the other certified ones. I know Av still has a gyro behind his panel for the STEC-55x behind a full glass Garmin deck. You have to remember, only a couple have been designed in this era.
 
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Henning said:
It depends, but for the most part I think not. I'd imagine the new Garmin ones and the experimental ones do, but not so much the other certified ones. I know Av still has a gyro behind his panel for the STEC-55x behind a full glass Garmin deck. You have to remember, only a couple have been designed in this era.
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Just as a counter point, Aspen has gotten approval to provide attitude data to some autopilots. The Avidyne in particular uses Aspen data. They can also feed data to some of the King autopilots. So far I haven't seen anything for the Century autopilots.
 
Clark1961 said:
Just as a counter point, Aspen has gotten approval to provide attitude data to some autopilots. The Avidyne in particular uses Aspen data. They can also feed data to some of the King autopilots. So far I haven't seen anything for the Century autopilots.
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Good to see that their developing the backwards compatibility. I imagine for the digital APs it's pretty straight forward, but I guess a generic digital to analog converter could handle most the rest. Can they build one cheap enough?:dunno:
 
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Henning said:
Good to see that their developing the backwards compatibility. I imagine for the digital APs it's pretty straight forward, but I guess a generic digital to analog converter could handle most the rest. Can they build one cheap enough?:dunno:
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The quick answer is that it just isn't that simple. The analogue converter unit (ACU) to drive the Aspen GPS steering had to matched to the autopilot or strange/random events happened. Until the ACU got matched properly the 'kota would just make a random right turn every 15 hours or so. Analogue computers are strange beasts.
 
Clark1961 said:
The quick answer is that it just isn't that simple. The analogue converter unit (ACU) to drive the Aspen GPS steering had to matched to the autopilot or strange/random events happened. Until the ACU got matched properly the 'kota would just make a random right turn every 15 hours or so. Analogue computers are strange beasts.
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Yeah, that's kinda what I thought, it's doable, just not really economically feasible. In your life time you'll replace/repair the gyro once or twice. I'm not sure there's a big enough market to make it viable unless it's simple.

Random turns are my normal experience with most autopilots.
 
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Lindberg said:
It blows bubbles.
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That's how my old scoutmaster survived in his cave diving accident.

SixPapaCharlie said:
>>> Sub question. Why doesn't the AI precess?
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The way I understand it is because if the four vanes like the others have stated. The AI will gimble lock up you've have to be really fing up to lock it up.

The DG only "precess" because the Earth is rotating under it. The precession caused by friction and error are small compared to the rotation error.

It's roughly 15* an hour.
 
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