N178LBGrumman American Avn. G-164B · 1977

On May 28, 2022, about 1340 central daylight time, a Grumman American Aviation G-164B airplane, N178LB, was destroyed when it was involved in an accident near Whiskerville, Arkansas. The pilot sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 137 aerial application flight.

The pilot was being trained by Kin-Co Ag Aviation Inc., a 14 CFR Part 137 operator. The airplane was owned, and the accident flight was operated, by Hackberry Flying Service, LLC. According to Kin-Co Ag Aviation Inc, they would do a verbal risk assessment together with a pilot before a flight as every chemical load was different, and every field was different. The operator and the pilot would study maps during the risk assessment and preflight planning process. For the accident flight, a verbal risk assessment was performed with the pilot. If there were obstacles at the field, management and the pilot would drive to the field first to perform a ground reconnaissance. Due to the absence of obstacles at the target field, a ground reconnaissance was not performed.

The operator that was training the pilot reported that the pilot departed for training purposes from the operator’s airstrip near Beech Grove, Arkansas, at 0910, and flew west toward Walnut Ridge, Arkansas. She returned at 1010, refueled the airplane, and flew to the east of Walcott, Arkansas, where she performed several practice aerial application passes over a rice field. The pilot returned to the operator’s airstrip at 1105 and shut down the airplane. She reported the airplane was working fine and there were no concerns with it.

At 1210, another company pilot from Kin-Co Ag Aviation Inc. departed in the airplane and performed an aerial application flight to configure the onboard aerial application system for the pilot. After several aerial application loads, the other company pilot returned to the operator’s airstrip, and the accident pilot departed in the airplane. The other company pilot reported the airplane was working fine and there were no concerns with it.

The pilot flew the airplane to the rice field she was scheduled to fertilize, located about 1.5 nm southwest of O’Kean, Arkansas. She performed several practice aerial application passes before she returned back to the operator’s airstrip. The hopper was loaded, and the airplane was refueled to about three quarters full of Jet A fuel. The fiberglass hopper had 2,500 lbs of dry chemical on board. The airplane then departed for the rice field.

Shortly after takeoff, the operator heard the pilot announce over the company radio frequency, that “I’ve got to land this airplane,” and there were no further radio transmissions from the pilot. The operator classified the pilot’s tone on the last radio transmission as “not distraught.” The operator was unable to tell if the engine was operating or not during the radio transmission due to the flight helmet microphone system that had noise cancelling properties.

After several attempts to contact the pilot over the radio with no success, a fellow company pilot from Kin-Co Ag Aviation Inc., who was already airborne, departed from his current rice field, and flew to the rice field where the pilot was scheduled to be. He observed black smoke rising in the air before arriving and then observed the wreckage once he arrived on scene.

A witness, who is a farmer who lives about 1.6 nm northwest of the accident site, reported that he was outside working on his farm when he heard the accident airplane flying nearby with a constant engine noise. The engine suddenly either “cut off” or “shut off,” and he heard no further engine noise. About 5 seconds later, he heard a loud impact noise, and then shortly after he observed black smoke emitting from the accident site. The witness immediately contacted first responders to report the accident. While the witness did not observe the accident sequence, he reported he is familiar with the engine noise emitted from the various turbine-powered airplanes used to provide aerial application services in the area.

The airplane came to rest upright near a ditch. A postimpact fire ensued and the wreckage was destroyed.

No flight track data existed for the accident flight.

A review of the pilot’s records found that she did not hold a Federal Aviation Administration (FAA) commercial pilot license with a single-engine land rating, which is required to operate a single-engine airplane under 14 CFR Part 137. According to FAA records, the pilot held type ratings in the Boeing 737, the McDonnell Douglas DC-10, and the De Havilland Canada DHC-8 series airplanes.

The pilot previously worked as a 14 CFR Part 121 commercial airline pilot. A review of the pilot’s training records showed that she was removed from the airline’s pilot training program and from the airline in December 2020, resulting from two unsatisfactory proficiency checks and two consecutive additional training sessions without being recommended.

The pilot attended an aerial application flight training course in May 2021 and an aerial application turbine engine transition training course in July 2021. The pilot passed both courses. The pilot received her 14 CFR Part 137 knowledge and skills endorsement in May 2021.

According to the operator that was training the pilot, she was very professional, she was a hard worker, she seemed safety oriented, and she caused him no concern.

The operator that was training the pilot reported the accident flight was the pilot’s first heavy aerial application load. The pilot’s husband reported that the pilot had previous experience in March 2022 performing practice aerial application work with water in the hopper.

According to the pilot’s husband, she left the commercial airline industry for the aerial application industry as she wanted to eventually become an aerial firefighting pilot in the McDonnell Douglas DC-10-30 Air Tanker. To become an aerial firefighting pilot, she wanted to obtain aerial application experience first.

The airplane, a bi-plane configuration originally known as an Ag Cat, was modified multiple times through the FAA Supplemental Type Certificate (STC) program. On February 13, 2003, via STC SA3645SW, the airplane was modified to a Fat Cat configuration with changes made to the fuselage and the installation of a 500-gallon hopper. The airplane was not fitted nor required to be fitted with a crash-resistant fuel system under the current standards or those in place at the time of manufacture. According to the current type certificate holder, Grumman American Aviation never offered an optional crash-resistant fuel system, nor are there any current known STC modifications for a crash-resistant fuel system.

The operator that was training the pilot also maintained the airplane. A review of the airplane’s maintenance records showed that a 100-hour inspection was performed on the engine on March 9, 2022. The records showed that an annual inspection was performed on the airframe on March 10, 2022. The records also showed that between July 20, 2020, and March 9, 2021, a required functional check flight was not signed off.

According to the pilot’s husband, she previously reported concerns to him about the airplane’s maintenance records that were maintained by the operator that was training her. On April 9, 2023, she sent her husband a text message that stated:

Harvey hasn’t signed logbooks yet, says there are a couple things that may or may not be 100% ok which no one would know anyway unless we were to crash it… I’m guessing he’s probably waiting to see if the airplane survives and if it does will finish so I can work lol.

14 CFR Part 91.417, Maintenance Records, states that maintenance records must include the signature and certificate number of the person approving the aircraft for return to service. 14 CFR Part 91.1, Responsibility and Authority of the Pilot in Command, states that the pilot in command of an aircraft is directly responsible for, and is the final authority as to, the operation of the aircraft. 14 CFR Part 137.19, Certification Requirements, and 14 CFR Part 137.31, Aircraft Requirements, state that no person may operate an aircraft unless that aircraft is certificated, airworthy, and equipped for agricultural operation.

The airplane was not equipped with automatic dependent surveillance–broadcast, nor was it required to be. Additionally, the airplane was not equipped with an emergency locator transmitter, nor was it required to be.

The witness classified the weather conditions at the time of the accident as clear, the temperature was about 85° F, and the wind originated from the south at about 10 mph.

The estimated density altitude for the closest meteorological reporting station was 1,338 ft above msl.

The airplane, a bi-plane configuration originally known as an Ag Cat, was modified multiple times through the FAA Supplemental Type Certificate (STC) program. On February 13, 2003, via STC SA3645SW, the airplane was modified to a Fat Cat configuration with changes made to the fuselage and the installation of a 500-gallon hopper. The airplane was not fitted nor required to be fitted with a crash-resistant fuel system under the current standards or those in place at the time of manufacture. According to the current type certificate holder, Grumman American Aviation never offered an optional crash-resistant fuel system, nor are there any current known STC modifications for a crash-resistant fuel system.

The operator that was training the pilot also maintained the airplane. A review of the airplane’s maintenance records showed that a 100-hour inspection was performed on the engine on March 9, 2022. The records showed that an annual inspection was performed on the airframe on March 10, 2022. The records also showed that between July 20, 2020, and March 9, 2021, a required functional check flight was not signed off.

According to the pilot’s husband, she previously reported concerns to him about the airplane’s maintenance records that were maintained by the operator that was training her. On April 9, 2023, she sent her husband a text message that stated:

Harvey hasn’t signed logbooks yet, says there are a couple things that may or may not be 100% ok which no one would know anyway unless we were to crash it… I’m guessing he’s probably waiting to see if the airplane survives and if it does will finish so I can work lol.

14 CFR Part 91.417, Maintenance Records, states that maintenance records must include the signature and certificate number of the person approving the aircraft for return to service. 14 CFR Part 91.1, Responsibility and Authority of the Pilot in Command, states that the pilot in command of an aircraft is directly responsible for, and is the final authority as to, the operation of the aircraft. 14 CFR Part 137.19, Certification Requirements, and 14 CFR Part 137.31, Aircraft Requirements, state that no person may operate an aircraft unless that aircraft is certificated, airworthy, and equipped for agricultural operation.

The airplane was not equipped with automatic dependent surveillance–broadcast, nor was it required to be. Additionally, the airplane was not equipped with an emergency locator transmitter, nor was it required to be.

The airplane came to rest near a north-to-south oriented ditch in between two large rice fields about 1.8 nm to the southeast of the intended rice field and about 3.8 nm northwest of the operator’s airstrip. The ground impact marks were consistent with the airplane impacting the west side of the ditch before traveling across the ditch and coming to rest on the east side of the ditch. There were no signs of any obstacles being impacted in the area.

All major structural airframe components were located at the accident site. Flight control continuity was established; however, multiple flight control cables were found fractured. Postaccident examination of the fractured flight control cables revealed signatures consistent with overload. The airframe fuel system and the cockpit all sustained fire damage.

The hopper was destroyed, and a large amount of chemical was observed in the forward fuselage area of the wreckage and near the empennage on the ground.

The engine and propeller were found separated from the airframe and did not sustain fire damage. Postaccident examination of the engine revealed no mechanical anomalies that would have precluded normal operation. Postaccident examination of the propeller revealed signatures consistent with high impact forces while rotating at low or no power and no mechanical anomalies that would have precluded normal operation.

There were no signs in the area surrounding the accident site that an emergency hopper dump procedure was performed before impact.

The airplane was equipped with an onboard camera and an aerial application lightbar system; however, neither item was identified in the wreckage.

FAA Safety Recommendation

The Australian Transport Safety Bureau (ATSB) investigated an Air Tractor AT-400 airplane accident that occurred on December 4, 2021, in Moree, Australia. The airplane was performing aerial application work and the pilot sustained fatal injuries. The investigation revealed that the airplane was not fitted, nor required to be fitted, with a crash-resistant fuel system under the current standards or those in place at the time of manufacture. As a result, a post-impact fire presents a significant risk of fire-related injuries to airplane occupants. This report discusses crash-resistant fuel systems and states in part:

Air Tractor aircraft, like many others, use the aircraft wing structure as an integral fuel tank. The AT-400 fuel tank met or exceeded the certification requirements. In an impact with the ground, traditional aircraft wing structures are comparatively rigid and will rupture, allowing their fuel contents to escape. Due to the high fluid pressures generated inside the fuel tank in ground impacts, fuel forced through these ruptures tends to mist into a large cloud, which increases the risk of ignition and conflagrates quickly into a large encompassing fire.

An aircraft fuel tank lined with a crash-resistant bladder can be more resistant to spilling or leaking due to its ability to retain its contents if distorted. Being flexible, the bladder can withstand changes to its shape without rupturing or splitting. The bladder is also more tolerant of penetrating objects being able to deform around the intruding body to some extent.

Bladder tanks are one technology designed to improve crashworthiness of fuel systems. Crash-resistant fuel systems reduce the risk of post-impact fire and provide occupants with more time to escape or be rescued.

The ATSB issued a safety recommendation to the FAA that states:

The ATSB recommends that the United States Federal Aviation Administration take action to address certification requirements for crash-resistant fuel systems for fixed wing aircraft to reduce the risk of post-impact fire.

Emergency Hopper Dump Procedure

A review of the FAA-approved Grumman American Aviation G-164B Pilot’s Operating Handbook did not find detailed information listed about performing an emergency hopper dump procedure.

Full Load Landing Procedure

A review of the FAA-approved Grumman American Aviation G-164B Pilot’s Operating Handbook did not find detailed information listed about performing a full load landing procedure.

The airplane was not equipped with a crashworthy flight data recorder, nor was it required to be.

According to the autopsy report issued by the Arkansas State Crime Laboratory, the cause of death was inhalation of products of combustion and the manner of death was accident. No significant natural disease was identified.

Toxicology testing performed by the FAA’s Forensic Sciences Laboratory identified carboxyhemoglobin at 30% in heart blood. In addition, diphenhydramine was identified at 79 ng/ml; zolpidem at 3 ng/ml; and quinine was detected in heart blood. All three of these were also detected in urine.

Restraint System

A photograph of the pilot in the accident airplane cockpit taken on the morning of the accident showed her adjusting a 4-point restraint system. The operator reported that she was using the 4-point restraint system for the accident flight. The restraint system was destroyed by the fire; however, the buckle was identified in the wreckage and was found to be latched.

Flight Helmet

The photograph showed her wearing a flight helmet. It was undetermined what make and model flight helmet she was using for the accident flight.

Flight Suit

The photograph did not show her wearing a fire-resistant flight suit, nor was she required to.

The operator that was training the pilot, Kin-Co Ag Aviation Inc., held a 14 CFR Part 137 operating certificate, NOSG, at the time of the accident.

The owner and operator of the airplane, Hackberry Flying Service, LLC, did not hold a 14 CFR Part 137 operating certificate at the time of the accident. A review of FAA records showed that this operator had previously surrendered their operating certificate to operate under 14 CFR Part 137.

A Safety Management System is not required for 14 CFR Part 137 operators.