Aviation Accident Summaries

Aviation Accident Summary CEN21LA167

Bridgeport, TX, USA

Aircraft #1

N3953N

BEECH 35

Analysis

The pilot and flight instructor were conducting an approach and landing following a simulated loss of engine power in gusting wind conditions. One witness stated that the airplane was descending from the north and appeared to be slow. It pulled up right before it hit trees, then “flipped” and hit the ground upright. Another witness saw the airplane at low altitude near the airport. He stated that the nose was up in the air and the tail barely cleared the power lines along the road. After crossing the road, the airplane pitched up and banked to the right. The right wing hit trees and the airplane descended out of sight. A review of weather information revealed gusting wind conditions and thermal activity. An encounter with a thermal, with associated turbulence or a downdraft, was possible given the synoptic conditions and observations. The recorded engine data revealed that the engine was operating at a low power setting, similar to idle, and no anomalies were noted. The airplane wreckage was sold for salvage and scrap before examination, and flight control continuity could not be confirmed. Based on the pilot and witness statements, it is likely that, during the simulated loss of engine power, the pilots failed to maintain adequate airspeed during the landing approach in gusting wind conditions and exceeded the airplane’s critical angle of attack, which resulted in an aerodynamic stall and loss of control.

Factual Information

HISTORY OF FLIGHTOn March 26, 2021, at 1527 central standard time, a Beech 35 airplane, N3953N, was substantially damaged when it was involved in an accident near Bridgeport, Texas. The airline transport pilot and flight instructor were seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated the purpose of the flight was to conduct his flight review. He and the instructor landed and fueled the airplane. Sometime after takeoff, they practiced a simulated loss of engine power and returned to the airport. While approaching the runway with engine power at idle, the airplane encountered a strong downdraft, but the pilot did not recall what happened after that. The instructor stated that he did not remember any of the accident flight. One witness stated that the airplane was descending from the north and appeared to be slow. It pulled up right before it hit the trees, then “flipped” and hit the ground upright. Another witness observed the airplane traveling at low altitude over a highway near the airport. He stated that the airplane’s nose was up in the air and the tail barely cleared the power lines along the road. After crossing the road, the nose pitched up and the airplane banked to the right. The right wing hit trees and the airplane descended out of sight. The witness stated that he could not hear the airplane as it passed over him on the road and did not recall if the propeller was turning. Automatic dependent surveillance – broadcast (ADS-B) data revealed that the airplane departed and entered a left traffic pattern for runway 18. On the downwind leg abeam the runway threshold, the airplane began to descend. While on short final, about 30 ft above ground level (agl), the airplane veered slightly left and began to climb. The final ADS-B point was recorded at 50 ft agl, and about 130 ft laterally from the accident site. AIRCRAFT INFORMATIONThe maintenance logbooks were not available for review. The owner stated that an annual inspection had been completed within the last year and that the engine had about 350 hours since the last overhaul. METEOROLOGICAL INFORMATIONOne witness stated that, just before the accident he checked the weather, and the wind was reported from the east about 15 mph. He added that the wind was gusting when he was outside at the accident site. The airport manager stated to the FAA that the wind gusts were 20 to 22 knots about the time of the accident. The surface observations just before the accident included wind from the south at 12 knots gusting to 17 knots, which resulted in an approximate 11-knot headwind and a 5-knot crosswind for runway 18. The synoptic conditions depicted no frontal or other boundaries to cause any large-scale wind shifts and the radar mosaics indicated no convective wind shear conditions were identified over the region at the time of the accident. A weather model sounding depicted southerly wind and a dry conditional unstable atmosphere which supported thermals through approximately 5,000 ft, with likely associated turbulence and downdrafts. There was an active AIRMET Tango for occasional moderate turbulence over the area which included the accident site. A pilot report of light turbulence at low levels was likely due to thermals. AIRPORT INFORMATIONThe maintenance logbooks were not available for review. The owner stated that an annual inspection had been completed within the last year and that the engine had about 350 hours since the last overhaul. WRECKAGE AND IMPACT INFORMATIONThe airplane came to rest upright in a residential yard. The wings both exhibited tree impact marks and sustained ground impact damage. The airplane sustained substantial damage to both wings, fuselage, and empennage. At the request of the NTSB, a local mechanic examined the airplane and determined that the fuel sector valve was working properly and that there was fuel available in the fuel system. Before a thorough examination of the wreckage could be conducted, the airplane wreckage was sold for salvage and scrap, and flight control continuity was not confirmed. The airplane was equipped with two electronic devices that contained non-volatile memory: a JPI Fuel Scan FS-450 and an Insight graphic engine monitor GEM 610. The JPI FS-450 can display fuel information, but the fuel status is dependent on the user to properly program the amount of fuel onboard the airplane before each flight. When powered on, the device displayed that the last remaining record of fuel used was 0.9 gallons, and the fuel remaining was 52.1 gallons. The Insight GEM 610 can record and display engine parameters. The recorded data revealed that the engine exhaust gas temperatures (EGT) and cylinder head temperatures (CHT) decreased toward the end of the flight, which corresponded to the airplane on the downwind leg of the traffic pattern. In the last 12 seconds of data, the EGTs began to increase.

Probable Cause and Findings

The pilots’ failure to maintain adequate airspeed during a simulated power-off approach in gusting wind conditions, which resulted in an exceedance of the airplane’s critical angle of attack, an aerodynamic stall, and loss of control.

 

Source: NTSB Aviation Accident Database

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