Aviation Accident Summaries

Aviation Accident Summary CHI05LA149

Senath, MO, USA

Aircraft #1

N9778G

Cessna 188

Analysis

The agricultural spray airplane was destroyed by ground impact and post impact fire after it hit a guy wire of a 1,040 foot radio tower antenna located near the cotton field the pilot was about to spray. A witness reported that he heard the airplane flying in the area and then he heard an explosion. He made a 911 emergency call, and then went outside and observed the tower falling to the ground. The inspection of the airplane revealed impact marks on the mid-span of the left wing, which were consistent with a wire strike. The propeller also exhibited gouging and scraping marks that were consistent with a wire strike. Witnesses reported that the pilot conducted a map study of the area to be sprayed since it was a "sensitive" area due to honeybees and homes near the cotton field that required spraying. The Memphis Sectional Aeronautical Chart the pilot used depicted the 1,040-foot tower. There were three sets of guy wires that anchored the tower. The three sets of guy wires were anchored at 120-degree intervals around the base of the tower. The bases of the guy wire anchors were about 425 feet from the base of the tower. An extra guy wire supported the tower. The anchor for the extra guy wire was located about 729 feet from the base of the tower in the southeast corner field where the tower was located. The FAA Advisory Circular AC 70/7460-1K, "Obstruction Marking and Lighting" advises that a pilot should maintain 2,000 feet horizontal clearance for a 2,000-foot tall tower to avoid all guy wires.

Factual Information

On June 18, 2005, at 1904 central daylight time, a Cessna 188, N9778G, was destroyed by ground impact and post impact fire after the agricultural spray airplane impacted a guy wire of a radio tower antenna near Senath, Missouri. The pilot was fatally injured. The 14 Code of Federal Regulations Part 137 aerial application flight departed Hornersville Memorial Airport (37M), Hornersville, Missouri, at 1900 on a local aerial application flight. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed. The wife of the pilot reported that the pilot departed Gosnell, Arkansas, at 0800 en route to 37M where he would be flying all day. She reported that she drove to 37M and brought him lunch. She reported the pilot had lunch, and then flew twice before landing at 1730. He ate again before flying the last field for the day. She reported that the last flight was a "sensitive" flight because there were honeybees and a house near the cotton field that needed spraying. She reported that he did a map study of the area since it was a sensitive area and he had not sprayed in that area before. The distance from Hornersville to the cotton field that needed spraying was about 6 nautical miles. The 1,040-foot tower with guy wires was located next to the cotton field. The tower is identified on the Memphis Sectional Aeronautical Chart about two miles west of Senath, Missouri. A witness reported that he heard the airplane flying in the area and then he heard an explosion. He made a 911 emergency call, and then went outside and observed the tower falling to the ground. He went to the impact site and observed the airplane on fire in the field. A Federal Aviation Administration (FAA) inspector examined the accident site. He reported that the airplane exhibited impact marks on the mid-span of the left wing that were consistent with a wire strike. The propeller also exhibited gouging and scraping marks that were consistent with a wire strike. The base of the tower was located at coordinates 36 degrees 7.892 minutes north, 90 degrees 11.588 minutes west. The airplane wreckage was located at coordinates 36 degrees 07.852 minutes north, 090 degrees 11.487 minutes west, about 607 feet from the base of the tower on a bearing of about 108 degrees. There were three sets of guy wires that anchored the tower. The three sets of guy wires were anchored at 120 degree intervals around the base of the tower. The base of the anchors were about 425 feet from the base of the tower. An extra guy wire supported the tower. The anchor for the extra guy wire was located about 729 feet from the base of the tower in the southeast corner field where the tower was located. The FAA Advisory Circular AC 70/7460-1K, "Obstruction Marking and Lighting" provides guidance for standards for marking and lighting structures to promote aviation safety. Section 21: "Guyed Structures" states the following: "The guys of a 2,000-foot (610m) skeletal tower are anchored from 1,600 feet (488m) to 2,000 feet (610m) from the base of the structure. This places a portion of the guys 1,500 feet (458m) from the tower at a height of between 125 feet (38m) to 500 feet (153m) AGL. 14 CFR part 91, section 119, requires pilots, when operating over other than congested areas, to remain at least 500 feet (153m) from man-made structures. Therefore, the tower must be cleared by 2,000 feet (610m) horizontally to avoid all guy wires. Properly maintained marking and lighting are important for increased conspicuity since the guys of a structure are difficult to see until aircraft are dangerously close." The pilot held a commercial certificate with single-engine land and single-engine sea ratings. The certificate had the following limitation: "Carrying passengers in airplanes for hire is prohibited at night and on cross-country flights of more than 50 nautical miles." The pilot held a second-class medical certificate with the following limitation: "Must wear corrective lenses for near and distant vision." The pilot reported his total flight time was 3,300 hours during his last medical examination on March 3, 2005. No autopsy or toxicology examinations were conducted. The FAA and Cessna Aircraft Company were parties to the investigation.

Probable Cause and Findings

The pilot's failure to maintain clearance from the tower guy wires. A factor was the extra antenna guy wire.

 

Source: NTSB Aviation Accident Database

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