Guy Johnstone wrote:
You may want to go the other way and put it together and postprocessing. Not terribly fast the 3100 is still capable of producing about 30 exposures and 10 seconds.
I agree with Guy. A long exposure will likely just give an undefined streak. I would suggest going to an airport to take pictures of takeoffs and landings with long exposures and post processing to see which effect you like the most. You will have many opportunities to practice before the big shoot.