I recently have been using my SPARK in areas of quite high radio usage. When looking at the available channels I saw that there were many red bars but the spark had chosen a blue channel bar that appeared clear. When attempting to fly however it was quite obvious that the spark was not happy as vertical control at take off was very unstable so a quick landing was made. I was wondering if the auto channel selection system had started to hop between channels and whether I should perhaps have made a manual selection. I may however have mis understood what the channel select is showing me. I was using a RC unit so maybe that is not using those channels, only the receiver phone. Any tech help?