Auto Pilot Setting
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I am trying to set my autopilot so that it will fly a circle without input from me
I have the plane in a bank (say 30 degrees) what is the setup for to accomplish thisDo I enter the bank, then select the ROLL HDG SEL then the ATT HOLD?
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bank your jet 30 degrees with hand then turn the right switch up but keep the left switch neutral (middle position).
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@jack72 said in Auto Pilot Setting:
I am trying to set my autopilot so that it will fly a circle without input from me
I have the plane in a bank (say 30 degrees) what is the setup for to accomplish thisDo I enter the bank, then select the ROLL HDG SEL then the ATT HOLD?
Your roll autopilot is only ever locked to the current steerpoint or heading bug (on your HSI). You can’t enter a specific bank angle to hold. The pitch is locked either to your current attitude (within margin) or your current altitude (hold).
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The AP pitch switch turns on and off the whole AP. With pitch switch centered the left switch doesn’t matter. To make a level constant bank turn set left switch to attitude, establish the bank, and then right switch to altitude. At the moment the right switch is set up or down the entire AP turns on and you’ll get altitude behavior in the pitch channel and roll hold behavior in the roll channel.
More easily you can engage that combo (roll attitude/ pitch alt) at any bank then hold the AP suspend paddle on the stick while establishing your desired bank and then let go of the paddle.
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I’ve never tried this but using [7] Mark on the ICP to define a new OFLY steerpoint … then set AP to follow that stpt … would presumably result in a stable circle pattern.
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@frederf said in Auto Pilot Setting:
To make a level constant bank turn set left switch to attitude, establish the bank, and then right switch to altitude.
Left switch is HDG / STRG, right one is ALT/ ATT
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@jack72 said in Auto Pilot Setting:
I am trying to set my autopilot so that it will fly a circle without input from me
I have the plane in a bank (say 30 degrees) what is the setup for to accomplish thisDo I enter the bank, then select the ROLL HDG SEL then the ATT HOLD?
If you use a Steerpoint it’s really easy, just set left switch down to STRG SEL, right up to ALT HOLD. As long as the SP isn’t set to Auto-advance (i.e. 3, not 3A) the ship will circle trying to hit SP 3 until you tell it not to. Good for the 6 minute hold when waiting to form up with other groups. Not elegant, but seems to work.
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@dumba said in Auto Pilot Setting:
@frederf said in Auto Pilot Setting:
To make a level constant bank turn set left switch to attitude, establish the bank, and then right switch to altitude.
Left switch is HDG / STRG, right one is ALT/ ATT
Left switch is heading/attitude/steering and right switch is altitude/off/attitude. The labels painted on the panel are HDG SEL, ATT HOLD, STRG SEL and ALT HOLD, A/P OFF, ALT HOLD if we want to be exact but they mean what was written in the first sentence. AP function is a combination of the roll channel job and the pitch channel job with the understanding that roll channel is ineffective if pitch channel switch is set to off. Making a level constant bank turn is the roll channel set to attitude and the pitch channel set to altitude.
The roll channel switch has three functions for three positions. There’s no “off” for the roll channel.
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I’ve sometimes wondered about the “AP Disconnect” switch … (left rear console, near the trim dials.)
Does it have some practical use? Or just an emergency backup “off” switch?
I think I’ve only ever clicked it by accident … and then wondered why my AP was broken
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@airtex2019 said in Auto Pilot Setting:
I’ve sometimes wondered about the “AP Disconnect” switch … (left rear console, near the trim dials.)
Does it have some practical use? Or just an emergency backup “off” switch?
I think I’ve only ever clicked it by accident … and then wondered why my AP was broken
If you have a sim-pit and things get out of whack between in-game settings and the analog dials or indicators in your cockpit, it can be useful as noted in the pic below
T.O. BMS1F-16CM-1:
“The TRIM/AP DISC switch is a two-position toggle switch. In NORM the stick trims are energized and AP operation is possible.
In DISC the stick trims and the autopilot are inhibited. Manual trim remains operative.”pg. 19 of the Training Manual:
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@semlerpdx I guess irl everything needs an off switch
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@airtex2019 RL aviation in general, autopilots are notorious for having issues, especially older ones. They may not follow the heading bug or radial, they can altitude “hunt” or not level out at all, you may have inadvertently turned it on and now want to turn it off, or good old it flew the approach for you and now you need to land. In the Viper of course you also have the paddle switch for momentary AP bypass but sometimes you need an easy and effective method to stop the stop the autopilot and/or stop a trim “runaway.” I teach my civilian flight students at least 3 different ways to disconnect the autopilot if needed. It’s so important that most civilian yokes that are nowhere near a HOTAS level buttons dedicate one of the few buttons on it to that function.
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@snake122 yeah I’ve watched enough “why planes crash” documentary series to be deathly afraid of AP… just want to scream at the tv – turn off the !@#$ autopilot!
I was more referring to the Trim disconnect, with my “everything needs an off switch” remark. seems oddly specific that it applies to the stick-trim hat (not the dials on the console)
but I suppose a dodgy/faulty trim hat could ruin your whole day, if it didn’t have an off switch
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@airtex2019 said in Auto Pilot Setting:
@snake122 yeah I’ve watched enough “why planes crash” documentary series to be deathly afraid of AP… just want to scream at the tv – turn off the !@#$ autopilot!
I was more referring to the Trim disconnect, with my “everything needs an off switch” remark. seems oddly specific that it applies to the stick-trim hat (not the dials on the console)
but I suppose a dodgy/faulty trim hat could ruin your whole day, if it didn’t have an off switch
That’s exactly the main reason why, many trim runaways are due to bad switches. A common elevator trim switch used in light aircraft, including new Cessnas, is actually a double switch placed next to each other in case one of them fails.