NTSB Factual Report

HISTORY OF FLIGHT

On September 2, 1993, at approximately 1115 mountain daylight time, a Cessna 180, N3120C, experienced an in flight break-up approximately nine miles north of Cheyenne, Wyoming. Visual meteorological conditions prevailed at the time and no flight plan was filed. The airplane was destroyed and the certified flight instructor and his two passengers were fatally injured. The flight had departed from Akron, Colorado, on September 2, 1993, at approximately 1000 hours and was en route to Riverton, Wyoming, on a personal flight.

The airplane was one of a flight of two en route to Riverton. The pilot in the other airplane, a Cessna 195, reported during a telephone interview and subsequent written statement, that he was told by the Cessna 180 pilot that the expected weather over Cheyenne was forecasted as the cloud tops to be 8,000 feet and the weather at Riverton was reporting 5,000 feet broken with unlimited visibility. Both aircraft took off and leveled off at 10,500 feet. The Cessna 195 pilot stated that when they were over Cheyenne, he could see the town through the broken clouds. The Cessna 180 pilot was approximately one-half mile to the west and in visual contact. Both flights were in communication with each other, and the Cessna 180 pilot reported to the Cessna 195 pilot that they would have to climb to 12,500 feet to get over the clouds.

The Cessna 195 pilot reported that he saw that the Cessna 180 was climbing and slightly ahead of his airplane. When the Cessna 195 reached approximately 11,300 feet, the airplane suddenly dropped and the vertical speed indicator (VSI) showed a 2,000 feet per minute descent. The pilot pulled back on the control yoke and the VSI went to 2,000 feet per minute climb and the stall warning horn sounded. The Cessna 195 pilot then called the Cessna 180 pilot and reported that he was in the clouds and the airplane was not responding properly. The Cessna 180 pilot told the Cessna 195 pilot to slowly climb out of the clouds. The Cessna 195 pilot reported that the VSI hit both ends of the stops three times. The airplane's directional gyro was spinning and the airplane was still descending and experiencing very heavy G forces. The pilot stated that he was experiencing moderate to severe turbulence. The airplane dropped to 9,000 feet and the pilot was able to see the ground and leveled at 8,500 feet below the clouds. When the pilot had regained full control and turned back to the proper heading, he tried to call the Cessna 180, but did not get a response. The Cessna 195 pilot continued the flight to Riverton, under the clouds and landed without further incident.

The owner of the Cessna 180, who is also the father to the pilot and one of the passengers in the Cessna 180, stated that he had received two messages on his answering machine from the pilot. The messages stated that they were in Akron and waiting for a rain shower to pass. The second message was that they were waiting a while longer and that their estimated time of arrival was around 1200 to 1230.

PERSONNEL INFORMATION

The pilot held a commercial pilot's certificate and certificated flight instructor certificate for single engine and instrument rating. The flight instructor certificate was renewed on 6/14/92. The pilot also held an airframe and powerplant certificate.

The pilot held a current Class II medical certificate dated 4/24/92. At the time of the medical, the pilot indicated a total flight time of 2,100 hours. The pilot's flight logbook was presumed to have been in the airplane and destroyed.

AIRCRAFT INFORMATION

The owner of the airplane stated that the aircraft logbooks were in the airplane at the time of the accident. The owner reported that the last annual inspection was completed sometime in April 1993. The engine had been overhauled, and he estimated a total of 50 hours had been accumulated since the overhaul. The pilot did not report any problems with the airplane to the owner and the owner was not aware of any problems that needed to be taken care of.

METEOROLOGICAL INFORMATION

At 0802 hours, the pilot contacted Denver Flight Service Station and requested a weather update. The Specialist reported a solid cloud coverage across the route of flight from Akron, Colorado, Cheyenne, Wyoming, Medicine Bow, Wyoming and Riverton, Wyoming. Light to moderate rain showers moving east at about 25 to 30 knots were forecast from Akron to Cheyenne and classified as Level I and Level II. There were flight precautions from the foothills westward into the mountains for northern Colorado and all of Wyoming. An airmet was issued for occasional mountain obscuration. The Specialist reported that VFR flight was not recommended into any mountain obscured areas. There was also an airmet issued for occasional moderate turbulence below 18,000 feet for the entire route of flight and occasional moderate rime icing.

The Specialist then reported the cloud conditions through northern Colorado. The forecast was for scattered clouds at 4,000 feet and broken clouds at 8,000 feet to 10,000 feet. In southeastern Wyoming, scattered clouds at 4,000 feet to 5,000 feet and broken clouds at 8,000 feet to 10,000 feet.

The Specialist concluded the conversation by reporting the winds aloft information for 9,000 feet and 12,000 feet at Akron and Medicine Bow. The conversation concluded at 0807.

At 1049, the pilot contacted Denver Flight Watch while over Cheyenne and requested a weather update for Cheyenne and Riverton.

The Specialist reported scattered level 1 shower activity between Cheyenne and Medicine Bow. The Specialist reported the current forecasts for Medicine Box, Rawlins and Riverton. The clouds were scattered to broken at several altitudes. The mountains were obscured with moderate turbulence below 18,000 feet and occasional moderate rime icing.

At 1050, the pilot reported that he was into the clouds about 50 miles southeast of Cheyenne. The flight was currently at 12,000 feet and climbing to 12,500 feet on top of the clouds. The Specialist reported the winds aloft at 12,000 feet at Medicine Bow as 290 degrees at 25 knots and 18,000 feet was 290 degrees at 41 knots.

The conversation concluded at 1051.

WRECKAGE AND IMPACT INFORMATION

The wreckage was scattered over an area of rolling terrain at varied elevations of 6,700 feet to 7,000 feet. The ground was hard and covered with short dry grass with no obstructions noted in the area. The wreckage distribution was scattered over a distance of approximately one mile on a magnetic heading of 10 degrees.

The first evidence of wreckage was identified as sections of the outboard left wing skin. Following the left wing sections, were the right horizontal stabilizer and a section of the right wing skin with an aileron hinge attached. In this area, several small pieces were found that were identified as right wing skin and then the right side elevator. Further into the path, the distance between the pieces increased. Several of the pieces were not directly identified but only recognized as wing skin.

The main wreckage was found on the side of a small hill. The wreckage had been consumed by fire and the grass immediately around the wreckage was burned. The fuselage was twisted in a "U" shape with the empennage positioned upright. The inboard sections of the wings were laying next to each other on the down hill side. The remains of the burned cockpit were near the empennage, with the engine laying next to the right side of the empennage under the bent vertical stabilizer. Next to the engine, which was laying on its side, was a large round crater that contained both propeller blades that had separated from the hub. Broken pieces of the engine crankcase and other pieces associated with the engine were in this crater. One propeller blade was bent aft, while the other blade was bent 90 degrees to the length of the blade and was cracked.

The vertical stabilizer, with the rudder attached, and the left horizontal stabilizer were still attached to the empennage. The tail wheel was intact. The left elevator was found approximately 30 feet uphill from the main wreckage. Approximately three feet of the right elevator and a one foot section of the inboard right horizontal stabilizer were still attached.

The entire length of the left wing strut was found at the main wreckage and remained attached to the inboard section of the wing. A small section of the flap was identified. Two sections of the wing spar were found, however, both underwent extreme heat distress and melting.

Both attaching ends of the right wing strut were found, however, the area between the attach points had melted away. Only a small two foot section of the wing spar was found. This piece was also melted at both ends.

The engine was positioned on its left side. The top of the engine crankcase was broken away, exposing the crankshaft, connecting rods and pistons. The accessory gears were broken and loose in the rear of the engine. Fin damage was noted to the cylinders. Severe heat distress was noted to the entire engine.

Throughout the wreckage distribution path, only skin sections were found. Some remains of the structural components were found at the main wreckage, however, these components underwent extreme heat distress and melting.

MEDICAL AND PATHOLOGICAL INFORMATION

The Laramie County Coroner reported that the cause of death was due to multiple traumatic injuries. Toxicological examination was negative.

ADDITIONAL DATA/INFORMATION

The wreckage was released to the owner on September 13, 1993. The owner had the wreckage buried at the accident site.

NTSB Probable Cause

IMPROPER IN-FLIGHT PLANNING/DECISON BY THE PILOT, WHICH RESULTED IN EXCEEDING THE DESIGN STRESS LIMITS OF THE AIRCRAFT AFTER ENCOUNTERING ADVERSE WEATHER. THE WEATHER CONDITIONS WERE RELATED FACTORS.