Aviation Accident Summaries

Aviation Accident Summary CEN21FA377

Fort Worth, TX, USA

Aircraft #1

N1472E

AERONCA 7AC

Analysis

The pilot and passenger were departing on a local flight. One witness, a flight instructor, described the takeoff roll as “extra-long” and stated that the airplane “appeared to get slow” during the initial climb. He reported that the airplane started a “roll to the right,” the left wing “fell,” and the airplane stalled and entered a spin from about 100 ft above ground level (agl). A second witness reported that, during the takeoff, the airplane appeared to be “barely climbing.” Near the end of the runway, about 100 ft agl, he observed a “strong right yaw” followed by a gradual left turn. The pilot appeared to lower the nose, then the airplane “rolled hard left,” and entered a spin. The airplane came to rest about 1,100 ft southeast of the departure end of the runway. Examination of the airframe and engine revealed no preimpact mechanical malfunctions or failures that would have precluded normal operation. A review of weight and balance information showed that the airplane was likely 225 lbs over its maximum takeoff weight at the time of the accident. Additionally, the density altitude at the time of the accident was about 2,600 ft. Both the overweight condition of the airplane and the density altitude conditions would have resulted in a significant loss of airplane performance, which is consistent with the witness observations of a long takeoff roll and slow rate of climb. It is likely that, during the initial climb, the pilot exceeded the airplane’s critical angle of attack, which resulted in an aerodynamic stall/spin at an altitude too low for recovery.

Factual Information

HISTORY OF FLIGHTOn August 21, 2021, about 0853 central daylight time, an Aeronca 7AC airplane, N1472E, sustained substantial damage when it was involved in an accident near Fort Worth, Texas. The airline transport pilot and the passenger sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the manager of Flying Oaks Airport (2TE2), Fort Worth, Texas, the pilot was going to conduct a local flight with his son. The pilot was seated in the rear seat, and the passenger was seated in the front seat. Multiple witnesses saw the airplane take off from runway 15. One witness, a flight instructor, reported that, during the initial takeoff roll, the airplane became “out of control” and “almost ground looped.” He described the subsequent takeoff roll as “extra-long” and stated that the airplane “appeared to get slow” during the initial climb. He reported that the airplane started a “roll to the right,” the left wing “fell,” and the airplane stalled and entered a spin about 100 ft above ground level (agl). A second witness reported that, during the takeoff, the airplane appeared to be “barely climbing.” Near the end of the runway, about 100 ft agl, he observed a “strong right yaw” followed by a gradual left turn. The pilot appeared to lower the nose, then the airplane “rolled hard left,” and entered a spin. The witnesses did not recall hearing any abnormal noises originating from the engine. PERSONNEL INFORMATIONAccording to Federal Aviation Administration (FAA) records, the pilot held several type ratings. His personal flight logs were not available for review, and his experience in the accident airplane was not determined. AIRCRAFT INFORMATIONThe pilot purchased the airplane in May 2021. Utilizing the airplane’s weight and balance records and the weights of the two occupants, weight and balance values were calculated for the accident flight. With a full fuel and oil load with no baggage onboard, at the time of departure, the airplane was 225.6 lbs over the maximum gross weight while the center of gravity was within limitations. An examination of the airplane’s maintenance records revealed no evidence of uncorrected mechanical discrepancies with the airframe or the engine. The maintenance records showed that a dorsal fin was installed onto the empennage in April 2020. The airplane, which had flight controls at both positions, only had flight instruments for the front seat. The airplane was not equipped with flaps, a stall warning system, or an angleofattack indicator. METEOROLOGICAL INFORMATIONThe estimated density altitude at the time of the accident was 2,610 ft above mean sea level (msl). AIRPORT INFORMATIONThe pilot purchased the airplane in May 2021. Utilizing the airplane’s weight and balance records and the weights of the two occupants, weight and balance values were calculated for the accident flight. With a full fuel and oil load with no baggage onboard, at the time of departure, the airplane was 225.6 lbs over the maximum gross weight while the center of gravity was within limitations. An examination of the airplane’s maintenance records revealed no evidence of uncorrected mechanical discrepancies with the airframe or the engine. The maintenance records showed that a dorsal fin was installed onto the empennage in April 2020. The airplane, which had flight controls at both positions, only had flight instruments for the front seat. The airplane was not equipped with flaps, a stall warning system, or an angleofattack indicator. WRECKAGE AND IMPACT INFORMATIONThe airplane came to rest about 1,100 ft southeast of the departure end of runway 15, on a magnetic heading of 079° at an elevation of about 860 ft msl. All major components were found at the accident site. The airplane sustained substantial damage to the fuselage and both wings. Flight control continuity was established for both cockpit stations. The single fuel tank, located between the cockpit and the firewall, was breached from the impact sequence. An FAA aviation safety inspector, who was on site the day of the accident, reported a strong odor of fuel at the accident site. There were no signs of a fuel leak on the airframe. Vegetation blighting was observed in the grass where the front of the airplane came to rest. Postaccident examination of the airframe and engine revealed no preimpact mechanical malfunctions or failures that would have precluded normal operation. ADDITIONAL INFORMATIONThe FAA Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B, discusses the effects of weight on an aircraft and states in part: The pilot should always be aware of the consequences of overloading. An overloaded aircraft may not be able to leave the ground, or if it does become airborne, it may exhibit unexpected and unusually poor flight characteristics. If not properly loaded, the initial indication of poor performance usually takes place during takeoff. Excessive weight reduces the flight performance in almost every respect. For example, the most important performance deficiencies of an overloaded aircraft are: • Higher takeoff speed • Longer takeoff run • Reduced rate and angle of climb • Reduced maneuverability • Higher stalling speed • Excessive weight on the nose wheel or tail wheel The pilot must be knowledgeable about the effect of weight on the performance of the particular aircraft being flown. Preflight planning should include a check of performance charts to determine if the aircraft’s weight may contribute to hazardous flight operations. Excessive weight in itself reduces the safety margins available to the pilot and becomes even more hazardous when other performance-reducing factors are combined with excess weight. FAA publication FAA-P-8740-2, Density Altitude, states in part: Density altitude is formally defined as “pressure altitude corrected for nonstandard temperature variations.” The formal definition of density altitude is certainly correct, but the important thing to understand is that density altitude is an indicator of aircraft performance. The term comes from the fact that the density of the air decreases with altitude. A “high” density altitude means that air density is reduced, which has an adverse impact on aircraft performance. Whether due to high altitude, high temperature, or both, reduced air density (reported in terms of density altitude) adversely affects aerodynamic performance and decreases the engine’s horsepower output.

Probable Cause and Findings

The pilot’s exceedance of the airplane’s critical angle of attack during the initial climb, which resulted in an aerodynamic stall. Contributing to the accident was the pilot’s inadequate preflight planning, which resulted in an exceedance of the airplane’s weight and balance limitations and decreased takeoff performance.

 

Source: NTSB Aviation Accident Database

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