King Air C90 E90
Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 300; Flight Crew Total 1100; Flight Crew Type 60
Situational Awareness; Training / Qualification
Deviation - Speed All Types; Deviation / Discrepancy - Procedural Weight And Balance; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control
Procedure; Human Factors
I was operating a skydive flight at 14;000 feet Flaps were set at 60% on the final portion of the jump run. I turned the green light on to indicate to the skydivers it was safe to climb out. As jumpers climbed out of the aircraft; my speed was 80 KIAS and with the added drag of three jumpers climbing outside I observed the speed slow to 75KIAS. With all skydivers going out in one large group; an aft-CG situation was encountered. Two jumpers were seated aft of the door in a location where we ask them not to sit. Some of the remaining skydivers had moved further aft from their original seated positions.As I was about to push the power forward to accelerate; the airspeed indicator had an instantaneous decay of 8 KIAS. Less than a second later the left wing stalled and the aircraft entered into a one turn spin. I immediately executed spin-recovery procedures. I believe my aerobatic experience and upset prevention and recovery training was a large factor in a quick response and successful recovery. Speed and g-load limits were not exceeded for the aircraft configuration.
C90 pilot operating a skydiving mission; reported getting slow at 14;000 feet as the jumpers begin grouping in and outside the aircraft for a group jump. The left wing stalled and the aircraft enters a one turn spin to the left before the recovery. An aft CG may also have been an issue as the divers moved to the door and behind it at very low airspeed.