I would like some help reviewing my tlog.  I wanted to test the Alt_Hold and Loiter, but my flight times stink. The hexacopter is seven pounds and I am using a 4S 5000mAh 50c lipo. Per the voltage_battery, It seems I get a considerable drop in voltage during takeoff.  Is this normal regarding the copter weight? 

Also, I am concerned regarding my zacc RAW_IMU_T reading.  I raised the APM above the PDB, and it helped considerably, but should I raise it higher?  Note:  The magfield looks okay.  

Attached is the tlog.  I would appreciate some assistance.

Thanks. 

2013-08-01 20-05-17.tlog