20110821019749A

On August 21, 2011 a callair model A-9G single engine tow airplane N7638V sustained substantial damage when it impacted terrain seconds after disconnecting from towing a Schweizer model 2-33 glider airplane. The sole occupant of the tow aircraft, an ATP with a recently revoked medical certificate and a reported 31000 hrs of flight time, was airlifted to a local hospital where he sustained fatel injuries. The glider aircraft, piloted by a student glider pilot, released from the tow aircraft and returned safely to its origination. The tow airplane was registered to and operated by marshal soaring club, operating from ross field airport (rmy) in Marshall, Michigan. Club members reported that on the day of the accident, all take off and landings including the accident flight were from the grass runway on a west heading. The A-9G had taken on approximately 25 gallons of avgas and had flown one more successful tow before the accident flight. Moments prior to the accident, the tow aircraft with the glider under tow departed from the grass runway. The rmy automated weather observation system (AWOS) reported the wind 290 at 12KTS, with gusts to 19KTS. Visual flight rules were in effect. The student glider pilot stated that this was the first time he had flown with this tow aircraft pilot instructor. He stated the winds were very gusty; indicated airspeed was varying, with variations that were getting larger when he was hit by a very high intensity thermal. He stated he lost sight of the tow aircraft, then seconds later finding it at approximately 60 degrees beneath him and slightly to the right. He stated his speed had increased to about 85MPH when he attempted to disconnect the tow rope. At first attempt, the disconnect level appeared stuck, and then seconds later, the level broke free. He continued his upward climb, bleeding off airspeed, to come back around to land. A witness stated that the takeoff appeared to be normal. However, when the aircraft reached the end of the runway, it was clear that there was some turbulence. The glider pilot appeared to be having some difficulty staying in position behind the tow plane. At one point, the glider was subjected to a tugging motion. He interpreted this as tow line slack being taken out; although, it did not appear to be too severe. Shortly after word, it was clear the aircraft had separated. The tow plane was approximately 350 feet above the ground (AGL). The right wing of the tow plane dropped and it entered a 60 to 70-degree nose dive attitude. The airplane completed about one-half of a rotation before he lost sight of it behind some trees. The airplane impacted an open field about a ½ mile west of the departure end of the runway. Post accident inspection showed the tow rope was not attached to either aircraft. A large portion of the rope was found 400FT east of the crash site. The rope had broken at approximately 15 feet from one end. A search to locate the remaining smaller portion of the broken rope was unsuccessful.