ERA20LA314

NTSB accident investigation · Zenair CH750 Cruzer · Boaz, AL · September 10, 2020

Accident · FatalClass 3 · LimitedFinal report
Date
September 10, 2020, 12:43 local (17:43 UTC)
Place
Boaz, AL · Wooded area
Injuries
1 fatal
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N656BNZenair CH750 Cruzer
Defining event
Enroute-cruise: Loss of control in flight
Weather
Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Eastern Region Aviation
Parties
AAIU, Zenith Aircraft, FAA/ FSDO
FAA report
20200910016759A
Case key
101954

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

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.

Findings · 4

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Ceiling/visibility/precip: low visibilityEnvironmental issues › Conditions/weather/phenomena · Decision related to conditionWilliam E Mcclain CH750 CRUZER: 1 caseAll aircraft: 175 casesProbable cause
Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedWilliam E Mcclain CH750 CRUZER: 1 caseAll aircraft: 1,681 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

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 5,400ft 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.

Factual narrative

The accident airplane was a high-wing, strut-braced, two-seat airplane constructed of conventional metal. The fuel system was configured with two 15-gallon wing tanks and a 2-gallon header tank, which was mounted just behind the engine. The airplane was equipped with a 10-inch Dynon Skyview HDX electronic flight instrumentation system, which included a primary flight display and multifunction display. The airplane was not equipped or certificated for flight in instrument meteorological conditions and could thus only be operated in visual meteorological conditions. On September 10, 2020, about 1243 central daylight time, an experimental amateur-built Zenair CH750 Cruzer airplane, N656BN, was substantially damaged when it was involved in an accident near Boaz, Alabama. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. On the day of the accident, the pilot planned to fly from Tom B. David Airport (CZL), Calhoun, Georgia; to Tupelo Regional Airport (TUP), Tupelo, Mississippi; from TUP to Northeast Alabama Regional Airport (GAD), Gadsden, Alabama; and from GAD to CZL. According to a family member, this flight was a "test run" for a flight that the pilot planned to conduct on September 14 from CZL to Conway Regional Airport at Cantrell Field (CXW), Conway, Arkansas. The family member also stated that the pilot had not previously flown to CXW and that he thought that the flight from CZL to TUP would be a “good test” because the flight to TUP was about one-half the distance to CXW. Before the flight from CZL to TUP, the pilot had topped off the fuel tanks in the airplane. Radar data and automatic dependent surveillance--broadcast data revealed that the airplane departed runway 25 at CZL about 0917 and then turned westbound until it was about 6 nautical miles (nm) east of TUP (near the area of Mooresville, Mississippi). The data also showed that the airplane then reversed course and flew east-southeast in the general direction of GAD at varying altitudes from about 2,500 to 5,400 ft mean sea level (msl) during cruise flight. As the airplane passed Nectar, Alabama, it turned to the north until reaching the area of Cleveland, Alabama, and then turned to the east-northeast in the direction of CZL. About 22 nm later, when the airplane was about 10 nm north-northwest of GAD (about 1.7 nm from the accident site), the airplane descended through 2,325 ft msl. Before radar contact was lost, the airplane’s groundspeed had slowed from about 70 to about 40 knots, and its descent rate was about 500 ft per minute. During a postaccident interview, the family member stated that the pilot sent her a text message from the air, stating that he had found TUP and was on his way back. Another family member thought that the pilot’s plan was to refuel at GAD (before returning to CZL) if the airplane had more than one-half of its fuel left. Later that day, one of the family members became concerned aboutthe pilot, so she called the airport manager at CZL and asked him to check the pilot's hangar to see if he had returned. Because the pilot was not there, the family member asked the airport manager to call the Federal Aviation Administration (FAA). About 1804, the FAA issued an alert notice for the overdue airplane. The airplane was subsequently located about 1030 on September 12. The accident site was about 10 nm from GAD and was approximately in line with the airplane’s track. The Alabama Department of Forensic Sciences, Huntsville, Alabama, performed an autopsy on the pilot. His cause of death was blunt force injuries. Autopsy findings included an enlarged heart and 50% atherosclerosis of his left anterior descending artery. Toxicological testing performed at the FAA Forensic Sciences Laboratory found ethanol and N propanol in the pilot’s blood. Ethanol can be the result of postmortem production, and N propanol can be produced by microbial processes. Tamsulosin was detected in the pilot’s blood and urine. Tamsulosin is generally a non impairing medication that is acceptable for FAA medical certification. The pilot had obtained a weather briefing during the evening before the accident flight. The weather forecasts (provided by Leidos Flight Service and issued by the National Weather Service) covered the weather conditions that were expected during the flight. No instrument meteorological conditions or restrictions to visibility were forecast near the accident site. Also, graphical forecasts for aviation indicated few to scattered clouds from 3,500 to 4,500 feet msl about the time of the accident. Low and mid-level troughs were in the area of the accident site and the freezing level above 17,000 ft msl. The closest official weather station to the accident site was the automated weather observing system (AWOS) at Albertville Regional Airport-Thomas J. Brumlik Field (8A0), Albertville, Alabama. According to the 8A0 AWOS, as well as other nearby AWOS and automated surface observing system sites,, the lowest cloud ceiling was about 2,000 ft above ground level (about 3,000 ft msl) with scattered and broken cloud layers through 4,000 ft above ground level (about 5,000 ft msl). Pilot reports indicated cloud ceilings as low as 2,700 feet msl about 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. According to FAA and pilot records, in addition to his pilot certificate, the pilot held an inspection certificate for the CH750 Cruzer. The pilot did not hold an instrument rating, so he could only operate under visual flight rules. No simulated or actual instrument time was recorded in his logbook. The pilot had not undergone FAA medical certification examinations and, as a sport pilot, was not required to do so. Examination of the accident site and wreckage revealed that the airplane struck the top of trees in a heavily forested area and impacted the ground in anose-down attitude of about 45°. There was no wreckage path and no indication of an in-flight fire or explosion. The elevation at the accident site was about 918 ft. The left wing was bent downward at the wing root, and a corresponding bend was visible on the lift strut for the left wing. The right wing displayed crush and compression damage, the right wing fuel tank was impact damaged and leaking fuel, and the right aileron was separated from its outboard attachment fitting but was still attached to the inboard attachment fitting. The engine was pushed back into the firewall. The throttle control was at idle. The fuel selector was positioned to the left tank, which contained about 2 1/4 gallons of fuel. The right tank contained about 3 gallons of fuel. The header tank also contained fuel, but the amount could not be determined because the fuel could not be recovered due to impact damage. Examination of the engine revealed that no internal components failed and that all cylinders were intact. Continuity of the drivetrain was established, and the connecting rods, pistons, cam, lifters, pushrods, rocker arms, induction system, and fuel system were all in good condition. The ignition system was unable to be tested because the spark plug wires had been cut and pulled apart during the impact sequence and the electronic coil packs were impact damaged. Visual examination of the ignition system revealed no preimpact anomalies.

Aircraft

Registration
N656BN
Reported as
Zenair CH750 Cruzer (No Series)
Category
Airplane, amateur-built
Serial number
C75-10639
Built
2018
Airframe hours
55
Engine
UL Power 350iS, 130 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Condition · November 30, 2018
Departed
CZL · Calhoun, GA
Destination
GAD · Gadsden, AL
Equipment
Electronic multifunction display, ADS-B, Electronic primary flight display

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
76
Injuries
Fatal
Certificate
Sport Pilot
Airplane ratings
Single-engine land
Medical
Sport pilot
Seat
Left
Restraint
3-point
Toxicology
Performed
Flight hours
112.5 total · 67.6 in this make and model · 84.1 as pilot in command · 7.1 in the last 90 days · 3.9 in the last 30 days

Weather

Conditions
Day
Wind
Variable at 3 knots
Visibility
10 statute miles
Lowest ceiling
2,700 ft broken
Temperature
82 °F, dew point 73 °F
Altimeter
30.18 inHg
Observed at
GAD, 10 nm away

Docket · 18

The files NTSB released with the investigation on September 20, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 70.3 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.