Pilot Debrief

Zenair CH750 CRUZER near Boaz, AL — 2020-09-10

Final reportERA20LA314
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Date
2020-09-10
Location
Boaz, AL, USA
Aircraft
Zenair CH750 CRUZER
Registration
N656BN
Category
Airplane
Highest injury
Fatal
Fatalities
1
Phase of flight
Descent

Probable cause

The pilot’s failure to maintain control of the airplane, which resulted in an aerodynamic stall and impact with trees and terrain. Contributing was the pilot’s continued visual flight rules flight into an area of low clouds.

Contributing factors

Contributing was the pilot’s continued visual flight rules flight into an area of low clouds.

NTSB narrative

On the day of the accident, the non-instrument-rated pilot was flying a "test run" for a multi-stop cross-country flight that he planned to conduct a few days later. Before the flight, he topped off the fuel tanks in the airplane. During the flight, the pilot sent a text message to a family member stating that he was on his way back to the departure airport. Radar and automatic dependent surveillance-broadcast data during the return portion of the flight showed that the pilot was flying at an altitude between about 2,500 and 5,400 ft mean sea level (msl). Before radar contact was lost, the airplane had descended through 2,325 ft msl (about 1,400 feet above the ground [agl]), and its groundspeed had slowed from about 70 to about 40 knots. Its descent rate was about 500 ft per minute. The airplane subsequently impacted trees and terrain in a heavily wooded area. The accident site was approximately in line with the airplane’s previously recorded ground track, about 1.7 nautical miles ahead of the last radar-recorded position. Examination of the accident site and wreckage revealed that there was no discernable wreckage path horizontally through the trees and that the airplane impacted the ground in a nose-down attitude of about 45°. The relatively intact condition of the wreckage and lack of wreckage path suggested that the airplane was in a low energy state with little forward velocity when it impacted the trees. The wreckage examination also showed that adequate fuel remained onboard and that the engine displayed no evidence of any preimpact malfunction or failure that would have precluded normal operation. The pilot had obtained a weather briefing during the evening before the accident flight. No instrument flight rules conditions or other restrictions to visibility were forecast. Graphical forecasts for aviation indicated few to scattered clouds at 3,500 to 4,500 ft msl about the time of the accident. The weather forecasts that the accident pilot received reflected the weather conditions during the flight, and the weather information was issued in sufficient time for the accident pilot to be aware of the expected conditions. The low and mid-level troughs in the area helped to induce cloud cover near the accident site. Automated weather observing system information from multiple reporting stations indicated that the lowest cloud ceiling was about 2,000 ft agl with cloud layers through 4,000 ft agl. Pilot reports indicated cloud ceilings as low as 1,600 ft agl around the time of the accident. Weather satellite information and pilot reports also indicated that the cloud tops were between 4,500 and 6,000 ft msl. Thus, when the pilot remained below 2,000 ft agl, the flight would have been in visual meteorological conditions (VMC). However, when the pilot operated the airplane between 2,700 and 6,000 ft msl, the flight would have encountered instrument meteorological conditions at times. The airplane’s varying altitudes (between about 2,500 and 5,400 ft msl) were likely the result of the pilot trying to remain in VMC. Autopsy results showed that the pilot had some atherosclerosis of one coronary artery identified. Because no evidence showed that an acute cardiac event occurred during the flight, the pilot’s cardiovascular medical condition was not likely a factor in the accident. A low level of ethanol and N-propanol were detected in the pilot’s blood; however, the ethanol was likely from sources other than ingestion and was not a factor in the accident. Given all of the available information, it is likely that at some point during the return leg of the flight, the pilot encountered clouds and was attempting to remain clear of them based on the observed weather conditions and the airplane’s flight path. Shortly before the accident occurred the airplane was descending and slowing. The low energy state of the wreckage suggest that the pilot may have stalled the airplane while at an altitude too low to recover, which resulted in the subsequent collision with trees and terrain.

Analysis

Primary failure mode
VFR into IMC
First missed decision gate
Pilot could have chosen to divert to GAD instead of continuing towards CZL.

NTSB coding

Evidence available

  • Video
  • ADS-B / radar
  • Photos
  • 18 docket documents
View NTSB final reportView NTSB docket

Docket documents18

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