Aviation Accident Summaries

Aviation Accident Summary CEN11FA616

Seward, NE, USA

Aircraft #1

N88CE

LARSON KEN W CHRISTEN EAGLE-II

Analysis

The flight instructor, who was seated in the front seat, was giving the private pilot, who was seated in the rear seat, a check-out in the single-engine biplane. The engine lost power on takeoff, and the airplane impacted a field. Examination of the airplane and engine revealed no preimpact mechanical malfunctions or failures that would have precluded normal operation; however the mixture control lever, which was located below and to the left of the rear-seated pilot's left knee (there was no mixture control in the front seat), was pulled out about 2 inches. The lever should have been full forward during takeoff. The propeller control was situated directly below the mixture control and found in the full forward position. The propeller control lever is usually adjusted by the pilot after takeoff. Although the mixture and propeller control levers were color-coded, it's possible that the 6'5" private pilot's left knee blocked his view of the controls due to his size and the small cockpit. The mixture control knob was slightly larger than the propeller control knob, but both were similar in shape. It is possible that the pilot thought he was adjusting the propeller control rather than the mixture control on takeoff and inadvertently shut off fuel to the engine. Postaccident examination of the mixture control cable from the cockpit to the engine revealed it moved freely and there was no evidence it had been moved during impact.

Factual Information

HISTORY OF FLIGHT On September 4, 2011, approximately 0935 central daylight time, an experimental-homebuilt, Larson Christen Eagle-II, N88CE, experienced a total loss of engine power shortly after takeoff from the Seward Municipal Airport (SWT), Seward, Nebraska. The airplane impacted a cornfield, and the pilot and flight instructor were fatally injured. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed and a flight plan had not been filed for the local instructional flight. An eyewitness described seeing the airplane flying low before it turned left and descended into the field. According to paperwork located in the wreckage, the pilot purchased the airplane on August 18, 2011, and this was his first flight since his purchase. The flight instructor, who had previously owned the airplane, was giving the pilot a check-out in the airplane. PERSONNEL INFORMATION The pilot, who was seated in the rear seat, held a private pilot certificate for airplane single-engine land and sea. His last Federal Aviation Administration (FAA) Third class medical was issued on March 16, 2011. At that time, the pilot reported a total of 1,700 hours. The flight instructor, who was seated in the front seat, held an airline transport pilot rating for airplane multi-engine land; and a commercial pilot certificate for airplane single-engine land. He also held a certified flight instructor certificate for single and multi-engine land airplane. The pilot's last FAA First class medical was issued on June 27, 2011. At that time, he reported a total of 9,700 hours. METEOROLOGICAL INFORMATION Weather at Lincoln Airport (LNK), Lincoln, Nebraska, approximately 16 miles east of the accident site, was reported as wind from 350 degrees at 6 knots, clear skies, visibility 10 miles, temperature 64 degrees, dewpoint 52 degrees, and a barometric pressure setting of 30.24 inches Hg. WRECKAGE AND IMPACT INFORMATION The airplane came to rest upright in a cornfield on a measured heading of 320 degrees, approximately 1,865 feet from the departure end of runway 34, and 475 feet east of the runway’s extended centerline. The airplane sustained substantial damage to the firewall, fuselage, all four wings, and the empennage. All major components of the airplane were accounted for at the accident site. Flight control continuity was established for all major flight controls to the cockpit. No anomalies or blockages were noted in the fuel system and fuel drained from the airplane was absent of debris and water. Examination of the engine revealed no mechanical deficiencies that would have precluded the engine from normal operation. The airplane was configured so only the person seated in the rear seat had access to the mixture and propeller controls. A review of photographs taken shortly after the accident revealed that the mixture control, which sets the amount of fuel added to the intake airflow, was pulled out approximately 2-inches. The mixture should be full forward during takeoff. The propeller control, which adjusts the propeller pitch and regulates the engine load as necessary to maintain the set R.P.M., was situated directly below the mixture control and was found full forward. The pilot would normally adjust the propeller control after takeoff. Examination of the mixture control cable from the cockpit to the engine revealed the cable moved freely and there was no evidence that it had been moved during impact. MEDICAL AND PATHOLOGICAL INFORMATION Autopsies were conducted on the both the pilot and the flight instructor by the Nebraska Institute of Forensic Sciences, INC., on September 7, 2011. The cause of death for both individuals was multiple, severe blunt force trauma of the head, trunk, and extremities. Toxicological testing was completed by the FAA Toxicology Accident Research laboratory, Oklahoma City, Oklahoma. The pilot tested negative for all items tested. The flight instructor tested positive for Rosuvastatin (marketed as Crestor to reduce cholesterol) in the liver and cavity blood. ADDITIONAL INFORMATION The mixture and propeller control levers both have knobs that are color coded so a pilot can visually differentiate between the two. The propeller control knob was black and the mixture control knob was red. The mixture control knob was also a little larger in size than the propeller control knob, but both knobs were round and similar in shape. According to the pilot's last FAA medical, he was 6'5" tall and weighed 220 pounds. The cockpit on the accident airplane was compact. An FAA inspector, who was 6'4" tall, and similar in weight and stature as the pilot, sat in the rear cockpit of another Christen Eagle II and noted that it was difficult to see the mixture and control levers. It was also difficult to close the canopy since the top of his head brushed up against it when it was closed. In a written statement, the inspector said, "While seated in the aircraft, I could not see the mixture or propeller controls, due to my left leg in the way. I could see the mixture only after I pushed my left leg over to the right. Pushing my left leg over was awkward and contrary to sitting in the aircraft in a relaxed state. The propeller control, which was located under the mixture, was very difficult to see. It was black in color and blended into the background which was also black in color." The inspector said another FAA inspector got into the front seat where the instructor was seated. The inspector was unable to see the mixture or propeller controls even after turning around in his seat. Additionally, due to the canopy quick release, he would not have been able to reach the controls if he had removed his seat belt and turned completely around in his seat.

Probable Cause and Findings

The pilot’s inadvertent pulling of the mixture control lever on takeoff, which shut down the engine.

 

Source: NTSB Aviation Accident Database

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