Hi I've just finished installing a Skyview System with 2 channel autopilot. Went out with a pilot yesterday and carried out a test flight with everything working correctly at 1200ft. The only adjustment I made was to increase turn rate to 2deg/Min otherwise every other autopilot parameter was left at factory default. I handed aircraft (Tecnam P2002 Sierra) back to the owner. Received a phone call later that night saying from the owner saying that everything worked well except when she flew over 5000ft the autopilot ordered a violent pitch up then down and began hunting, porpoising and got progressively worse. She disconnected the autopilot and hand flew from there. She didn't say if she tried to engage the autopilot again once below 5000ft. Has anyone come across this before? Thanks.
Autopilot pitch channel issue.
- Thread starter adamsiaki
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- Mar 23, 2005
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We haven't heard of altitude-related issues like this.
The best way for us to work with you on an issue like this is if you give us a call. There are ways that we can collect data from the aircraft if you and the customer are able to work with us. The best way to get started is to give support a call at 425-402-0433.
The best way for us to work with you on an issue like this is if you give us a call. There are ways that we can collect data from the aircraft if you and the customer are able to work with us. The best way to get started is to give support a call at 425-402-0433.
Hi, So full story. Just discussed what occurred with my client. With autopilot set and climbing at 5000ft + she heard a loud bang and the nose pitched down, she then said she heard another loud bang and the nose pitched up, where upon she disengage the autopilot. What we believe happened is that the system was asking her to input same electric trim to aid the pitch channel servo but she didn't see the indications on the top bar and it got to a point where the servo slipped this was even more pronounced because the slip setting was at the default 100% hence the loud bang. So will talk through the trim messages with my client and adjust the torque slip setting accordingly. If anyone disagrees with this diagnosis please post. The more thoughts the better.
Thanks.
Thanks.
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- Mar 23, 2005
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The bang does sounds like the servo slipping after not being able to apply enough torque, which would happen if the aircraft is out of trim. That slippage is designed to happen, and as you found, the autopilot trim indication is provided to avoid this scenario.
I am getting a lot of SLIP and TRIM indications on my pitch trim on an RV-8. I have the slip set at 100%. I have the actuator arm mounted on on top (Lowest torque) mounting hole. I am thinking of lowering it to the middle hole as I think I have plenty of arm travel available. Before I do this was jus wondering in raising the torque available will make any difference in the slippage. Picture of the mounting is attached.Attachments
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As long as you have enough arm travel such that you have full control throw on the aircraft, acceptable angular deflection on the servo (no possibility of going overcenter), moving the middle hole will provide more force, and that should help with slips. Now if after you've done that, you're still having persistent trim notifications, you may have a servo hardware issue that we'd need to help you with.