STEC 30 - silence the altitude alerts

josephades

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ja
Hi,

Is it possible to silence the "trim up" and "trim down" alerts for the pitch hold functionality of the STEC 30? The noise is very annoying

Thanks!
 
If you refuse to trim the airplane when it ask you can try trimming it before engaging the autopilot.
 
The altitude will increase and decrease by 10-20-30 feet depending on turbulence, etc.

I completely ignore the alarm and I do not trim up/down and the altitude still holds its place

So I prefer to silence the annoying alarm and just be notified by the annunciator lights of the autopilot itself
 
I believe if you pull hte TC out there's a trimmer you can adjust the volume. There's no user way to decrease (or elimiate) either the TRIM or DISCONNECT beeps.
 
Is it coming through the audio panel into headsets? If so there may be an adjustable trimmer on the unswitched audio input of the audio panel.


Most likely illegal to "silence" these alerts. I bet the flight manual supplement requires verification that they work.
 
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The altitude will increase and decrease by 10-20-30 feet depending on turbulence, etc.

I completely ignore the alarm and I do not trim up/down and the altitude still holds its place

So I prefer to silence the annoying alarm and just be notified by the annunciator lights of the autopilot itself

Understand what is happening, and you'll understand why you DON'T want to do that.

The trim alarm is telling you that the pitch servo is having to apply a great deal of force to keep the plane on altitude. That means you are placing great strain on the pitch servo, and it will fail much sooner.

In addition, if you fly along in an untrimmed state (which, by definition, you are if you're getting the alarm) even intermittently sounding, then when you disconnect the A/P, you'll have a very sudden and often dramatic pitch excursion (up or down, depending upon the direction of the mis-trim). At best, it's disconcerting, but could easily be dangerous - maybe put you right into a stall. It's even worse for your situational awareness if you have it occur in IMC.

Proper practice is to get all trimmed for altitude, power and speed and, when the plane is finished stabilizing at the proper speed and attitude for the altitude and power, only then engage the Altitude Hold. In my Bonanza, that usually means about two minutes of steady acceleration and small trim tweaks prior to engaging ALT, and even then, "i'll disconnect the Altitude Hold a few minutes later for the purpose of fine-tuning trim.

If you've ever priced overhauling an S-Tec servo, you'll get it!
 
The altitude will increase and decrease by 10-20-30 feet depending on turbulence, etc.

I completely ignore the alarm and I do not trim up/down and the altitude still holds its place

So I prefer to silence the annoying alarm and just be notified by the annunciator lights of the autopilot itself

If you're going to ignore a system, deactivate it, in your case why not just just trim the plane level yourself and leave the alt hold off.
 
Understand what is happening, and you'll understand why you DON'T want to do that.

The trim alarm is telling you that the pitch servo is having to apply a great deal of force to keep the plane on altitude. That means you are placing great strain on the pitch servo, and it will fail much sooner.

In addition, if you fly along in an untrimmed state (which, by definition, you are if you're getting the alarm) even intermittently sounding, then when you disconnect the A/P, you'll have a very sudden and often dramatic pitch excursion (up or down, depending upon the direction of the mis-trim). At best, it's disconcerting, but could easily be dangerous - maybe put you right into a stall. It's even worse for your situational awareness if you have it occur in IMC.

Proper practice is to get all trimmed for altitude, power and speed and, when the plane is finished stabilizing at the proper speed and attitude for the altitude and power, only then engage the Altitude Hold. In my Bonanza, that usually means about two minutes of steady acceleration and small trim tweaks prior to engaging ALT, and even then, "i'll disconnect the Altitude Hold a few minutes later for the purpose of fine-tuning trim.

If you've ever priced overhauling an S-Tec servo, you'll get it!

I like to climb about 100 foot high then push the nose down and descend to get "on-speed" quickly.
 
The problem is not that you want to ignore them but that many installations are LOUDER than they need to be. Mine was and I asked STEC support and they told me how to adjust it. Actually, I have electric trim so it's only the disconnect feep but I still have to warn any passengers prior to disconnnecting the autopilot that there's going to be a loud beep (the STEC guys did point out the duration is decreased if you hold the button down rather than pressing it).

I've only twice had an uncommanded disconnect. You're darned straight that you want that warning.
 
I like to climb about 100 foot high then push the nose down and descend to get "on-speed" quickly.

That does work...
 
Yeah, I have the STEC 30 in my 182 and I am chasing the dang trim alerts all freaking day...and I trim the heck outta the plane. It is just hyper sensitive. I have learned based on the conditions when I need to actually make a subtle trim adjustment and when I can just add a touch of forward or back pressure for just a moment while still engaged to shut it up.

As mentioned, first make sure the plane is configured and flying right where you want it hands off before engaging the altitude hold.

Either way when chasing the alerts I make the adjustment on the yoke THEN make the trim change. If you just chase it with the wheel you will be at it the whole flight.
 
Nobody else notice he said he was using it in turbulence? It's going to sound off constantly when doing that.
 
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