compass warning and right motor red LED

[PatR]

If the only times you see that warning is briefly during the aircraft boot up process there probably isn’t any reason to be concerned. It’s pretty common for an H to generate a GPS lost, compass, or OA not available warning during the early stages of the power up. They happen with mine as well.

I do not know the reason for the boot up stage warnings. It may be a temporary voltage regulation glitch, system check anomaly, or something else. If the H is being moved during boot up, like removing the gimbal lock during power up, holding the H while pressing the button and setting it down afterwards, or carrying the H during power up, or other actions that cause movement during boot up, a problem will be induced because the accelerometers will not be able to self zero.

Part of my checklist includes assuring the system is in Angle mode with OA turned off during boot up. Waiting for a minimum of a stable 10 satellite count on both aircraft and controller before arming motors is another. My reason for starting out in Angle is to reduce the chances of a control input error and to have the system in a flight mode with the least number of reported loss of control incidents. I don’t know if that makes a difference but most fly aways seem to occur in Smart mode.

After launch has another check list where control function and hover stability is verified. If the H wanders in hover it is landed to perform an accelerometer calibration. If there is any indication of a control issue during the check it is landed and powered down for a re-boot. After that a secondary control check would be performed. If no issues and all else look good it will be flown with more attention given to visually flying the aircraft to verify proper control response. If the post launch check continued to indicate control issues the H would be landed for a complete calibration process.

There is not much reason to be concerned about a brief warning message while on the ground during boot up, unless the warning is persistent. Warnings while airborne have more importance, with an airborne compass warning the most concerning. If you get one, land immediately. Don’t try to fly it anywhere, just be in Angle mode and land. If you can turn off the GPS in the process, so much the better.

 

[biltno]

Thanks Pat
It gives me piece of mind to fly now.
I was thinking my compass was failing. I never got a warning in flight which now I know is more apt to be a failure

 

[PatR]

Glad to help.

One more thing, a GPS warning in flight is no big deal. Just don’t use Smart mode or RTH during a lost GPS condition. There are rarely any problems flying without GPS when in Angle mode.

A brief GPS lost warning can happen when swinging the landing gear. Don’t know why they happen but they normally don’t affect flight performance and clear quickly. Some early H’s had compass warnings occur during gear cycling in flight. A few of those became problems.

As the system samples data at 5Hz it can generate a warning for an anomaly that lasted for only a fraction of a second. Those conditions came and went before any message popped up and long gone by the time we’ve read the pop up. The few we get are more nuisance than concern with the exception of compass in flight. Those we should always alert to.

 

[Old Dude]

I appreciate PatR mentioning to point the nose of the H North. I remember the Q manual said to do that, but the H Quick Manual does not say to point it North. Maybe that’s why I had to do it a second time back to back.