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Hi,

I've been working with an APM2 unit that seems to be rather temperamental. Fix times are very long, (3+ minutes in some cases in the wide outdoors) and logs seem to indicate that the fix can be lost several times during the course of a flight.

Flight example A:

Here's the KML of "flight A" rendered on Google Earth. You can see several "ramps" on the render where the position suddenly changes to lat 0.00 and long 0.00.

Here's the accompanying graph from Mission Planner, showing the GPS fixes and drops.

Flight example B:

Another render from GE, but the path from the log is very hard to see and is rendered as a series of dots rather than a "roller coaster" type pathway (not quite sure if that's me or GE, but this KMZ was created the same way as in example A). This one, of course, has the mission plotted in the KMZ. Another graph from MP, showing fixes or lack thereof. Long time to fix, then several drops through the mission. Used Auto on this mission, and the first time it caused the plane to behave erratically. Auto made the plane take some jerky rolling motions, quickly jerking back and forth - aborted the test and went back to manual and landed the plan shortly thereafter. Not sure if that was the PID or if it had something to do with the GPS fix.

After flight "B," I took the plane on another mission, but the APM log from that is fairly useless. Activating Auto on that mission took the plane into a steep dive, with increased throttle.

I would post other examples of flight logs, but you really can't tell much from the logs or the KMLs due to the fact that positions are not recorded. The APM is powered by a 2S LiPo source, via BEC/voltage regulator, set for 5.5v, on the output rail.

Any ideas what could be the culprit, or how to solve this? Thank you.