Autopilot not holding altitude.

[Death Merchant]

The autopilot does not seem to hold altitude very well. I find myself constantly adjusting the trim to keep the aircraft at the right altitude. Is this normal, or am I doing something wrong?

I take the time to trim the aircraft before setting the AP to Alt, but it doesn't seem to help.

Thanks,

DM 

[Lace]

Works fine for me.  Are you sure ALT HOLD is engaged?

[razo+r]

Sometimes it works, sometimes it just oscillates up and down. 

Haven't managed to get consistent results yet. 

[WizzRD]

1 hour ago, razo+r said:

Sometimes it works, sometimes it just oscillates up and down.

Make sure you have it trimmed for 1G before turning the AP on.

[Devil 505]

I had it trimmed and noticed the same oscillation after it had been working fine. Not sure what it is.  I always set the trim on cold start.

[Sarge55]

Perhaps your speed is too low and it's starting to oscillate.  The A/P does not control the throttle, you have to monitor it.

[dporter22]

I'm also unable to get altitude hold to work. AP is on and Alt Hold is selected but it doesn't do anything.

Alt Sel doesn't work either, nor does it hold bank.

Essentially useless.

 

[Flapjacks]

for altitude hold, trim till level then engage, or you can trim while a/p is on if you know which way to trim and alt hold will engage. Alt select works but you have to be at mil power and it'll eventually start making pitch adjustments. 

[dporter22]

Yes, I've tried leveling and trimming many times but it doesn't work. None of the modes work really. 

Haven't tried being exactly in mil power for the Alt select. Will try but that shouldn't be necessary.

Vastly better autopilot in the A-10, F-16, and F-18.

[doedkoett]

8 minutes ago, dporter22 said:

Yes, I've tried leveling and trimming many times but it doesn't work. None of the modes work really. 

Haven't tried being exactly in mil power for the Alt select. Will try but that shouldn't be necessary.

Vastly better autopilot in the A-10, F-16, and F-18.

The AP-page on the UFC tells you the minimum speed you need to be in for the Altitude Select to climb to the selected altitude. If you’re under that speed it will only hold your current altitude. Not so sure it cares what power setting you’re at, as long as you’re above the min climb speed. 

[Chipwich]

It seems like the only time I've had an issue with ALT HLD it when trying to engage it when the VV is more than 3 to 5 units off of the horizon bar.

[dporter22]

So it appears the autopilot works in Missions, Instant Action, etc., but doesn't work Multiplayer or in Sedlo's Red Flag DLC.

Odd.

[Zahnatom]

sometimes it works, sometimes it doesnt. i might have missed something but quite often it'll only do heading mode or attitude mode or even nav steering mode but just not do commanded altitude hold or even regular altitude hold. it just ignores it. Even in the same flight

[Scofflaw]

I noticed sometimes I can break the autopilot altitude functions. It tends to happen when I'm fighting with it, and at one point the autopilot will refuse to enable any kind of altitude hold function.

I'll have to try to replicate it to see if I'm doing something wrong.

[TheGhostOfDefi]

On 6/29/2023 at 11:28 PM, Devil 505 said:

I had it trimmed and noticed the same oscillation after it had been working fine. Not sure what it is.  I always set the trim on cold start.

Are you may in radar elevation hold instead of Baro? 

[Death Merchant]

On 6/29/2023 at 5:32 AM, Lace said:

Works fine for me.  Are you sure ALT HOLD is engaged?

Yeah, alt is engaged, I can tell by the *. I'm in Baro. It only works if I trim well, but won't hold in turns. 

12 hours ago, dporter22 said:

So it appears the autopilot works in Missions, Instant Action, etc., but doesn't work Multiplayer or in Sedlo's Red Flag DLC.

Odd.

Hhmmm.. I've been having problems in MP. I'll try it in a local mission and see if it acts differently.

[GrEaSeLiTeNiN]

On 7/1/2023 at 5:09 AM, Zahnatom said:

sometimes it works, sometimes it doesnt. i might have missed something but quite often it'll only do heading mode or attitude mode or even nav steering mode but just not do commanded altitude hold or even regular altitude hold. it just ignores it. Even in the same flight

+1
Same, inconsistent results with altitude hold/select modes. Also, it seems it doesn't let you drop altitude if you key in a lower altitude setting, from say a current alt hold setting of 1500 to 1000 ft radar, but the reverse (going higher) will work though sometimes it won’t. (Does not work when Alt warning or Master Caution is on, understandably.)

Edited July 20, 2023 by GrEaSeLiTeNiN

[Father Cool]

I have seen this also. Flying along autopilot on while I go heads down to sort out MFD's. Head back up and I've dropped by 5000ft. Yet sometimes holds just fine.

[felixx75]

On 7/19/2023 at 5:32 PM, GrEaSeLiTeNiN said:

+1
Same, inconsistent results with altitude hold/select modes. Also, it seems it doesn't let you drop altitude if you key in a lower altitude setting, from say a current alt hold setting of 1500 to 1000 ft radar, but the reverse (going higher) will work though sometimes it won’t. (Does not work when Alt warning or Master Caution is on, understandably.)

 

Yes, you can set a lower altitude. Since the autopilot always uses the current speed as a reference and wants to maintain it, you have to reduce thrust in order to sink.

[GrEaSeLiTeNiN]

14 hours ago, felixx75 said:

Yes, you can set a lower altitude. Since the autopilot always uses the current speed as a reference and wants to maintain it, you have to reduce thrust in order to sink.

Hey, thanks for the tip. Did more testing and watched the TF radar alt. So alt hold setting does work. But my throttle had to be near mil power (full loadout in my test). Sometimes without adjusting the throttle, the aircraft could still reach the new lower or higher alt setting. If not, I just had to nudge the throttle in the corresponding direction - less to descend, more to climb - basically to 'shake' it out of its current hold, and then set it back to near mil power. 

[LizardKingYB]

Glad to see Im not alone with this issue.

[dporter22]

I've tested the autopilot many times now in several different missions and it just doesn't work properly. Sometimes it sort of does, most times not.

It might have something to do with the fact that something is wrong with the flight controls because I have to input significant nose down trim as soon as I take off.  All trims are neutral on the ground and I press the takeoff trim button before takeoff. 

[Jayhawk1971]

vor 16 Minuten schrieb dporter22:

I've tested the autopilot many times now in several different missions and it just doesn't work properly. Sometimes it sort of does, most times not.

It might have something to do with the fact that something is wrong with the flight controls because I have to input significant nose down trim as soon as I take off.  All trims are neutral on the ground and I press the takeoff trim button before takeoff. 

 

[Nealius]

BARO alt hold works fine for me, but only once per mission. If I deselect BARO the UFC claims AP is still on. If I use paddle switch to turn AP off, I am then unable to get BARO to work again for the duration of the mission. It will * in the UFC, but won't actually work.

[WizzRD]

8 hours ago, dporter22 said:

It might have something to do with the fact that something is wrong with the flight controls because I have to input significant nose down trim as soon as I take off.  All trims are neutral on the ground and I press the takeoff trim button before takeoff. 

Nothing wrong with the flight controls at all. You are supposed to trim down after TO. I suggest you read up on this in the manual, starting at page 112.

I am using the AP alot (Attitude and Altítude Hold) and the only time so far I had problems with it bobbing up and down was in a mission with heavy turbulence flying low level. Make sure you are trimmed at 1G and if you still are bobbing try to add/ remove 1 or 2 more clicks of trim - and ofc give the plane some time to settle.