Aviation Accident Summaries

Aviation Accident Summary CEN22LA297

Air Force Academy, CO, USA

Aircraft #1

N469AK

CUB CRAFTERS INC CC18-180

Analysis

The glider tow pilot had completed one flight and was returning to the airport following the second tow of the day. The pilot reported that, during the approach, he encountered a meteorological effect and the airplane drifted to the left and the pilot decided to initiate a go-around. As the airplane was accelerating during the go-around, it started “turning/yawing” even though the pilot was trying to accelerate straight and level. The pilot surmised this was from the same meteorological effect that initially pushed the airplane left. The pilot noticed that the airplane seemed to yaw to the right, the airplane began descending, touched down, and came to rest inverted in a grass field, resulting in substantial damage to both wings and the empennage. The pilot admitted to first responders that he had consumed alcohol earlier that morning. The pilot was evaluated at a hospital, where he was diagnosed with alcohol intoxication based on a serum ethanol test result of 0.079 g/dL collected about one hour after the accident. It is likely that the pilot was experiencing impairing effects of ethanol at the time of the accident. It is unknown whether ethanol’s impairing effects were worsened by altitude effects (the field elevation of the airport was about 6,500 ft above mean sea level); however, it is likely that ethanol effects increased the pilot’s risk of making serious errors and diminished his ability to effectively maintain airplane control. Thus, pilot impairment from effects of alcohol consumption likely contributed to the accident.

Factual Information

On July 1, 2022, about 1225 mountain daylight time, a Cub Crafters CC18-180 airplane, N469AK, sustained substantial damage when it was involved in an accident at the U.S. Air Force Academy, Colorado. The pilot sustained minor injury. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 glider tow flight. The airplane was owned, operated, and maintained by Akima Logistics Services LLC, a federal government contractor. The airplane was part of a fleet used to tow gliders for the U.S. Air Force Academy cadet glider flight training program. Civilian pilots are employed to operate the airplanes. On the day of the accident, the pilot reported for duty to assume the afternoon shift around 1145 and received the daily safety brief from the lead tow pilot. The accident occurred following the pilot’s second glider tow of the day. The pilot classified the approach to runway 16R as normal and stated that he was preparing for a wheel landing. The pilot reported that he encountered “meteorological conditions I hadn’t seen/felt before,” and the airplane began to “drift quickly left” “more forcibly than normal turning tendencies.” The pilot decided to initiate a go-around. As the airplane accelerated during the go-around, it started “turning/yawing” even though the pilot was trying to accelerate straight and level. The pilot surmised this was from the same meteorological effect that initially pushed the airplane left, and he classified it as a “wind vane effect.” The pilot noticed that the airplane seemed to yaw to the right without the wing drop characteristics of an aerodynamic stall. The airplane began descending, touched down, and came to rest inverted in a grass field. The glider tow rope remained attached to the airplane. The pilot egressed from the airplane via the cockpit door without further incident. The airplane sustained substantial damage to both wings and the empennage. The pilot reported that there were no preimpact mechanical malfunctions or failures with the airframe or the engine that would have precluded normal operation. First responders provided medical treatment to the pilot at the accident site. The first responders reported that they smelled alcohol on the pilot’s breath in the ambulance. The pilot admitted to first responders that he had consumed alcohol earlier that morning. The pilot’s evaluation upon arrival at the local hospital included a clinical serum ethanol test that was collected at 1324 and showed a serum ethanol level of 0.079 g/dL. The physician’s note documented that first responders reported that the pilot smelled like alcohol and had been drinking 8 hours before the flight. The physician documented that the pilot admitted to drinking alcohol the night before the accident date but could not state the amount that he had consumed or when he had stopped drinking, although the pilot felt that it had been more than 8 hours before flying. The physician documented alcohol intoxication among the pilot’s visit diagnoses. The FAA Forensic Sciences Laboratory performed toxicological testing of leftover specimens from the pilot’s postaccident hospital care that found ethanol at 0.057 g/dL in the pilot’s blood. The pilot’s employer subjected him to a non-Department of Transportation (DOT) breath alcohol test following the accident. According to records of this test, the test was performed at 1702, and was negative. The pilot’s employer also subjected him to a non-DOT urine drug test following the accident. According to records of this test, it was collected at 1707. A medical review officer verified the urine drug test results, reporting the test as negative for tested-for substances.

Probable Cause and Findings

The pilot’s failure to maintain airplane control during the go-around, which resulted in impact with terrain. Contributing to the accident was the pilot’s impairment from the effects of alcohol consumption.

 

Source: NTSB Aviation Accident Database

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