TAKE_OFF in Auto mode

Matek F405 Wing w/ v3.9 Arduplane
Mini Talon

I setup a simply mission for take off. Setup for 18 degrees climb to 175 feet followed by a RTL Way Point click Home Location and Write WPs. Switched to Auto mode (ensuring I had GPS lock and simulated a throw and the motor spun up as it should. Repeated those steps again, except this time I actually threw the aircraft and it took off beautifully and then the motor stopped, spun briefly, stopped, spun briefly and stopped and the plane hit the ground.

This is my first Arduplane build and I am sure I am missed a critical step.

Should clarify, that on the second launch I simply put it in FBWA mode, spun up the motor to 65% and threw the aircraft level and it flew fine.

Any insight as to what I may be missing in my auto take off mission?

@kerrycorcoran providing a log file is a good place to start from when asking for help, as it usually contains a lot of vital information.
you said you‘ve triggered takeoff as your first mission item by switching to AUTO but did not actually launch your plane after the motor spun up. did you restart your mission or depower and repower your setup before attempting the actual launch?

To clarify, the first attempt I set the mission, set to auto, had my wife fake throw to ensure the motor would spin up and then she threw it while the motor was still spinning. Almost immediately after it took off (was going fine) the motor stopped, spun again, stopped. At this point it was still low so I moved the sticks so I could get it to the ground under control. I should note the throttle (when launched) was at the zero position - I did not know where it needed to be.

I just reviewed ow to capture the logs (http://ardupilot.org/copter/docs/common-downloading-and-analyzing-data-logs-in-mission-planner.html) but when I go to the Download Dataflash Logs via MavLink there isn’t any logs listed. I assume I have to grab the logs BEFORE removing power?

EDIT: I found a log file on the field laptop (mission planner/logs - not sure if I should upload it or what the next steps would be.

If you have had a telemetry connection and your GCS logging is on (by default it is) your laptop saves the logs too. As far as i know it contains same data with the on-board logs.