Need help analyzing ntsb report of possible autopilot stall

[rmcdaniel2]

Can an instructor have me analyze the accident report below? I have read the full narrative and my guess is that, after taking off 315 pounds over maximum takeoff weight the pilot climbed to 4000 feet and turned on the autopilot. As it was programmed to continue climbing, the autopilot progressively increased the angle of attack in order to maintain lift of the overloaded aircraft. This continued until the critical angle attack was reached and aircraft stalled. An aggravating factor was that the stall speed was greater than Vso as the aircraft was in uncoordinated flight. If this was the scenario, should not the pilot have disengaged the autopilot, reduce the angle of attack, and centered the ball? According to the report, the pilot was apparently pulling back on the stick rather than forward: " The officer's report stated that the pilot's son observed the pilot "pulling backwards on the control yoke of the aircraft trying to keep the aircraft's nose up." The report stated that the pilot's son "grabbed the right sided yoke and attempted to help his father keep the aircraft nose elevated." Any insight that any instructor familiar with the S22 and the Avidyne avionics package can shed on the most likely course of events that led to this tragedy and any tips on how to best manage an overloaded aircraft would be greatly appreciated!
NTSB Identification: CHI06FA245.
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
14 CFR Part 91: General Aviation
Accident occurred Monday, August 28, 2006 in Indianapolis, IN
Probable Cause Approval Date: 8/15/2008
Aircraft: Cirrus SR22, registration: N91MB
Injuries: 1 Fatal, 3 Serious.
The right seat passenger reported that the takeoff and initial climb were uneventful until the airplane reached about 4,000 feet of altitude. That was when he noticed that the sound of the engine had changed and saw that the pilot was struggling to control the airplane. The airplane went through a series of three quick rolls and the wing dipped down. The airplane entered a counterclockwise spin. The pilot told the right seat passenger to pull the emergency parachute handle, so he pulled the throttle back to idle, and then pulled the parachute handle. The airplane impacted a water retention pond about 4 seconds later. Witnesses observed the airplane descending through the clouds with a partially deployed parachute. The inspection of the engine and airframe revealed no pre-existing anomalies. The engine data obtained from the Multi-Function Display indicated the engine was operating at full power for the entire flight. Instrument meteorological conditions prevailed with variable cloud bases of 400 - 1,100 feet above the ground (agl) and with cloud tops reported at 3,200 feet above mean sea level. The baggage found in the baggage compartment weighed 262 pounds. The weight limit of the baggage compartment was 130 pounds maximum. The calculated takeoff condition weight of the accident airplane was 3,715 pounds. The Maximum Takeoff Weight was limited to 3,400 pounds. An aircraft performance study, which utilized data extracted from accident airplane, indicated that the airplane's airspeed decayed until the stall angle of attack of the wing was exceeded. The airplane was in a stalled condition for about 30 seconds and then entered a spin.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The pilot's failure to maintain sufficient airspeed which resulted in a stall and subsequent spin. Contributing to the accident were the pilot's inadequate preflight planning, and the overloaded condition of the airplane.
Full narrative available at nstb.gov