First of all, sorry for your crash....
As it looks like, you won't be able to pin down the source of your crashes, like many of us WooKong-crashers couldn't.....that's a fact.
The question is: What can you do to avoid future crashes.....?
Avoid to activate the built-in Power Protection..... complicated, useless and an ongoing source of troubles.....
Rather use one of those cheap LiPo alarms....they always work.
Get your GPS unit as far away as possible from any other electronics......
Make sure the GPS unit doesn't get too much vibrations......
When ever you go to a new location, perform the Compass calibration.....forgetting that might lead to a nice crash.....
If you fly close to a "critical" geomagnetic location like North-or South pole, just check with a normal "analog" compass if there is any strange behaviour of the compass needle. If it "dances" arround, don't fly.
GPS and compass work very closely together (althought nobody really knows exactly how....), so even a perfect Sat-lock might lead to a crash if the compass goes bananas....
Geomagnetic fields, power-lines, heavy WiFi traffic, concrete buildings, close-by airports....all that can lead to throw off the compass and lead to a crash.
There is a bunch of different smartphone Apps to make "magnetic" life" easier:
https://play.google.com/store/apps/details?id=com.eclipsim.gpsstatus2&hl=de
http://www.hotto.de/mobileapps/iphonemagneticinclinationmeter.html
http://www.androidpit.de/de/android/market/apps/app/binaryearth.geomagneticfield/Geomagnetic-Field
....and a lot more.
Also always check for Solar activity....
http://www.multirotorforums.com/sho...-Firmware-5-24&p=120093&viewfull=1#post120093 Post # 18
When it's "cold" (below ~ 10° C ) warm up your LiPo's....flying with cold LiPo's caused some serious crashes already, since the LiPo's loose a lot of power when they are cold.
Try to train your flying skills in manual mode....most of the time it's the only thing what can get you out of trouble if the copter starts to act weired, since manual mode requires the least information from GPS/Compass/Altimeter
Since I never fly away too far, I set the Failsafe on my transmitter in a way that the copter just hoovers in Atti-Mode.....not GPS-Mode
Return-To-Home is a nice feature on paper, but according to the many reported crashes and Fly-aways, it's a feature which is at the very best in an early beta-state....It only works if GPS and compass are providing clean, useful data to the Flight Controller, but this is something you can never be sure of....
If you need it for some reason, make always sure that you get an indication by the LED that the home-position has been recorded successfully.....
Apart from that, the DJI hardware is - simply speaking - just cheap crap. Every smartphone and every cheap navigation system is 10x faster and more reliable to aquire a GPS-lock than (most) Multirotor GPS's. The DJI software has been developed into a patchwork of a lot of features, where non of the features work reliably.....there were so many Firmware updates already....and every update fixed one issue and raised 2 new ones. In it's existing form, the WooKong is just not reliable enough to trust it with a bunch of 1000's $$ worth of equipment attached.....
Have a look at the ZeroUAV YS-X6 or the Xaircraft SuperX Flight Controllers.......
Hope this helps a bit
Chris