ATL94FA166

The pilot was on a local flight, about two miles northwest of the departure airport. Witnesses heard a loud noise, then observed a wing separate from the glider, while the glider was maneuvering. The main wreckage was found in a wooded area, about 1,000 feet east of where the separated left wing was located. Fracture examination of the left wing spar showed evidence of overload. There was also evidence of high g-loading on the wing skin and spar carry through areas. Prior to the accident, the pilot had logged 53 hours of flying time in gliders (153 flights). He had flown the sgs 1-34R on two occasions prior to the accident, with a total flight time of .8 hours. The majority of his flying time was logged in the sgs 2-33.

History of flight

On August 27, 1994, at 1310 central daylight time, a Schweizer SGS 1-34R, N1132S, collided with trees and terrain, following an in-flight separation of the left wing while maneuvering, near Maylene, Alabama. The private pilot was fatally injured. The glider was destroyed. The aircraft was operated under the provisions of 14 CFR Part 91 by the Birmingham Soaring Society, Inc. Visual meteorological conditions existed at the time, and no flight plan was filed for the local, personal flight. The flight originated at the Flying X Ranch, in Montevallo, Alabama, about 1240.

A flying club pilot, Mr. Jerry Linley, observed the accident pilot, Mr. Jack Dunwoody, as he arrived at the Flying X Ranch, prior to the accident flight. They discussed the weather conditions, and the availability of the club's Schweizer SGS 1- 34R. The aircraft was available, and Mr. Dunwoody performed his preflight inspection. He also commented that he would review the aircraft performance speeds. During general conversation, Mr. Dunwoody was observed to be in good health, with no visible signs of stress or preoccupation. Mr. Linley also observed Mr. Dunwoody's takeoff. The launch proceeded smoothly, and the takeoff and initial climb appeared normal. He last observed the aircraft after the release from the tow aircraft, but he did not witness the accident.

Several witnesses were located following the accident. One witness reported that he walked out of his back door, and saw the glider, which appeared to be in normal flight. From his vantage point, the glider appeared to be in a left turn, and a shallow bank. Seconds later, he heard a loud noise, and the "right" wing came up towards the fuselage. He stated that the noise sounded like a board breaking when stepped on. He saw pieces falling from the aircraft, but was unsure if the right wing separated from the airframe. He saw some clouds in the area, but not in the immediate vicinity of the glider. He never saw the glider penetrate any clouds at any time.

Another witness was inside a building, and heard a loud, cracking sound. He stepped outside, and saw an aircraft with one wing, spiralling nose down. The aircraft went behind some trees, and he heard a crashing sound.

Another witness was standing outside, when she saw the aircraft go by. She stated that she saw he aircraft go into the clouds, and then she heard a loud noise. She saw a wing "flying off" the airplane, followed by other "particles."

Personnel information

An examination of the accident pilot's logbook revealed the following: The pilots total flying time was about 53 hours (132 flights), including .8 hours in the SGS 1-34R (2 flights). His first logged glider flight occurred on January 11, 1992. The aircraft that was utilized during his initial phase of training was a Schweizer SGS 2-33. His initial solo flight occurred on August 9, 1992, in an SGS 2-33. His first attempt at the private pilot practical examination took place about one year later, on August 28, 1993. The pilot failed his first attempt at the practical examination, and logbook entries show that after several additional flights, the practical examination was again taken on September 11, 1993, with satisfactory results. His first flight in a Schweizer SGS 1-34R was performed on May 21, 1994, which included .5 hours of flight time. The second flight in the SGS 1-34R (which was the last 1-34R flight prior to the accident flight) occurred on June 19, 1994, and included .3 hours of flying time. Both of these flights took place in N1132S. In the remarks section of the logbook entry of May 21, the entry indicated "gusty, some thermals," and on the June 15 flight, the remarks included "No thermal activity."

Mr. Billy Singleton, who is a designated pilot examiner, flew both practical examination flights with the accident pilot. He reported that the first attempt was graded unsatisfactorily due to difficulties with landing accuracy. He reported that additional instruction was performed, emphasizing landing practice. The second attempt at the practical examination was satisfactory. He also recalled about 30 minutes of ground instruction with Mr. Dunwoody about the flight characteristics of the SGS 1-34R. This instruction was not associated with any particular flight. Mr. Singleton could not recall any unusual tendencies shown by Mr. Dunwoody regarding airwork flying ability.

During the 90 day period prior to the accident, the pilot had logged 8 flights, with a total flying time of about 3.2 hours. During the 30 day period prior to the accident, he logged 3 flights, all on August 7, 1994, and all in the SGS 2-33.

The accident pilot did not possess any ratings or certificates other than "private pilot-glider aero tow." Additional information on the pilot is included in the section titled "First Pilot Information."

Aircraft information

Information on the aircraft is included in this report at the section titled "Aircraft Information."

Leslie E. Schweizer, Vice President, Engineering and Quality Control, Schweizer, Aircraft Corporation, participated in the investigation during the follow up examination of the wreckage. He reported that the limit load factor for this glider was +5.33 g, and the ultimate load factor was +8.0 g. He also stated that this glider is considered a high performance glider, with a high design speed, and a low stall speed. Therefore, the capability exists to develop large load factors beyond the design limits, in a maximum unchecked maneuver above the maneuvering speed. The SGS 1-34R has a design speed of 150 mph, a maneuvering speed of 83 mph, and a stall speed of 36 mph. The load factor that can be developed in a maximum maneuver, at 135 mph (placard red line speed, or .9 X design speed) is +14g.

Meteorological information

Weather information for Birmingham, Alabama (BHM) is included in this report at the section titled "Weather Information."

One of the pilots in the Birmingham Soaring Society was flying an instructional flight, in the vicinity of the crash site of N1132S, at approximately 1330, on the day of the accident. At the time of the flight, he was not aware that an accident had occurred. Weather conditions at the time of the takeoff included calm surface winds, and a temperature of 90 degrees F. Estimated in flight visibility at 2,500 feet was 7 to 10 miles, in haze. Winds aloft were from a southeasterly direction at about 10 miles per hour. Turbulence was evident, but not greater than would be expected for August. After releasing from the tow plane, average climb rates of 200 to 300 feet per minute were common, with isolated areas of 500 feet per minute lift observed. He estimated the scattered cloud layer to be about 4,500 to 5,000 feet during the flight. He did experience isolated areas of thermal activity which required full control deflection to maintain aircraft attitude.

Wreckage and impact information

The main wreckage was located in a wooded area, about two miles northwest of the departure airport (Flying X Ranch). The left wing was found on a hill, about 1,000 feet due west of the main wreckage. In the area between the left wing and the main wreckage, two sections of left wing skin, and a trailing edge extrusion from the left wing, were found. A wreckage distribution diagram is included as an attachment to this report.

The main wreckage came to rest near the trunks of several large trees. Several large, freshly broken branches were found adjacent to, and on top of, the wreckage pieces. The nose and cockpit sections were found in a crater, which was about 2 feet deep, and 4 feet in diameter. The nose and cockpit were crushed in an aft direction, to the bulkhead behind the pilot seat. Flight control continuity was confirmed from the cockpit area aft, to the rudder and elevator.

The left wing was found to have separated from the aircraft at a point approximately 8 inches outboard of the root rib. T