Santa Cruz Low-cost UAV GNC System


Posted by: Gabriel Elkaim

It was supposed to be a routine test.

Towards the end of the year, December 30th, we were going to fly to collect some data to verify our attitude estimation filters. It was a bright clear day, cold, with almost no wind to speak of.

As per our usual routine, we set up down at the field, and flew the small R/C plane first to make sure that flying conditions were appropriately benign.

We did our first flight around the patch with the UAV, and it seemed to be doing fine. We were suffering telemetry dropouts, and we were a bit paranoid because we had crashed from an R/C outage on the prior flight. We had replace the RX with a better one that would not suffer from signal fading.

After a 5-6 minute flight, we landed and swapped out the battery. We tried to download the flight data off of the SD card, but could not get it to read. We figured we would get some more data and then call it a day.

As an important note, the autopilot at this point is passively listening in on the R/C and recording the sensors. It is not driving anything, and is just there as a passenger on the aircraft.

About two minutes into the flight, the pilot (Greg) called out that he had lost control of the A/C and it went into a steep dive ending with a loud crunch into the parking lot.