KOLB COMPANY FIRESTAR KXP
Cave Junction, OR — March 7, 2024
Event Information
| Date | March 7, 2024 |
| Event Type | ACC |
| NTSB Number | WPR24FA104 |
| Event ID | 20240307193897 |
| Location | Cave Junction, OR |
| Country | USA |
| Coordinates | 42.11174, -123.68126 |
| Airport | ILLINOIS VALLEY |
| Highest Injury | FATL |
Aircraft
| Make | KOLB COMPANY |
| Model | FIRESTAR KXP |
| Category | AIR |
| FAR Part | 091 |
| Aircraft Damage | SUBS |
Conditions
| Light Condition | DAYL |
| Weather | VMC |
Injuries
| Fatal | 1 |
| Serious | 0 |
| Minor | 0 |
| None | 0 |
| Total Injured | 1 |
Probable Cause
The pilot's exceedance of the airplane's critical angle of attack during a turn, which resulted in an aerodynamic stall. Contributing to the accident was the pilot's use of potentially impairing substances with bipolar disorder, which resulted in a decreased reaction time during a stall recovery at a low altitude.
Full Narrative
On March 7, 2024, about 1124 Pacific standard time, a Kolb Firestar KXP airplane, N4443G, was substantially damaged when it was involved in an accident near Cave Junction, Oregon. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight.
Witnesses reported that the airplane departed on runway 36 for a local flight following the installation of an overhauled engine. The witnesses observed the airplane turn left to the northwest, at about 500 ft agl. The airplane continued to turn left in an approximate 30° to 40° bank to a southeast heading. One witness stated that they saw the airplane descend about 100 ft in a slightly nose-down pitch attitude before it entered a 90° nose-down attitude and descended towards the ground. The witness lost sight of the airplane before impact.
According to witnesses, the light sport pilot had accumulated about 4,500 hours of flight time at the time of the accident. A review of the pilot’s logbook records indicated about 2,126 hours of total flight experience. Witnesses reported that the pilot displayed a positive attitude the morning of the accident and his behavior was not out of the ordinary.
Examination of the accident site revealed that the main wreckage was located about 0.14 nautical miles northwest of the departure end of runway 36. The wreckage came to rest in an open field. The first identified point of contact was a tree with broken branches about 40 ft northwest of the main wreckage. Several broken branches were found adjacent to the tree. Ground scars were observed consistent with the airplane's left wing and nose section making initial contact with the ground, followed by the leading edge of the right wing. Two propeller blade fragments were the furthest identifiable components within the debris field, located about 50 to 60 ft northeast of the main wreckage. All major structural components of the airplane were located within the wreckage debris path.
Examination of the airframe did not reveal any pre-impact mechanical anomalies or failures. The fuselage cage and supporting steel structures were crushed aft, consistent with impact. The tailboom structure had sheared rivets at its attachment point located in the aft section of the fuselage. Flight control continuity was established from the cockpit to all major flight control surfaces. The left and right wings remained attached to the fuselage cage. Multiple wing truss ribs sustained damage consistent with impact and remained attached to the anchor points throughout the wings. The left and right ailerons remained attached to the respective anchor points. The aileron control tubes were traced, and the hardware was secured to its respective attachment points in the left and right upper tubular trusses. Fuel odor was present at the main wreckage site. The fuel tank was empty of fuel and was breached on its side wall. The externally mounted fuel filter was intact and connected to the fuel tank by fuel hoses.
Examination of the engine did not reveal any pre-impact mechanical anomalies or failures. The engine was separated from its engine mounts. Both propeller blades were impact damaged but remained attached to the propeller hub and flange, which was connected to the crankshaft. The engine case sustained minor impact damage. Mechanical continuity was established throughout the rotating group, valvetrain, and accessory section as the crankshaft was manually rotated by hand using the propeller. The spark plugs displayed coloration consistent with normal wear. The electrode coloration was symmetrical, one electrode was free of mechanical damage, and the other electrode sustained impact damage. The air intake and exhaust systems remained attached and were both impact-damaged. The air filter was impact-damaged and remained attached to the carburetor. The interior of the filter was unremarkable. The fuel filter bowl remained attached and was secured and unremarkable. The BING carburetor was separated from its mounting pad and remained intact. The carburetor fuel filter was also unremarkable.
According to information gathered from the patient's family, the pilot suffered severe depression and bipolar disorder. The details of the pilot’s illness and his response to treatment are unknown. The pilot’s wife called local authorities the night before the accident, as she believed that the pilot needed a mental health evaluation, and the pilot was then evaluated by a Sheriff’s deputy. The pilot reported that he was under the care of a physician, took medication for his mental illness, and denied any intent for self harm. The deputy determined that the pilot did not meet the criteria to be detained for safety. Following the crash, the pilot’s wife stated that he would not have killed himself due to his religious beliefs.
According to Title 14 CFR Chapter I Subpart D, Part 67, Medical Standards and Certification, bipolar disorder is a psychiatric condition that is initially disqualifying and per Aviation Medical Examiner (AME) guidance, all applicants with this diagnosis must have their medical application denied or deferred. The AME must then submit all relevant medical information and clinical status reports, which will be examined and require an FAA decision, normally made by a Federal Air Surgeon.
As stated under Title 14 CFR Chapter 1, Subpart D, Part 61 Subpart J - Sport Pilots, light sport aircraft pilots generally do not need an FAA medical certificate, instead using a valid U.S. driver's license to certify they are medically fit to fly. However, according to Title 14 CFR Part 61.306(b)(1-4):
(b) A person using a U.S. driver's license to meet the requirements of this paragraph must—
(1) Comply with each restriction and limitation imposed by that person's U.S. driver's license and any judicial or administrative order applying to the operation of a motor vehicle;
(2) Have been found eligible for the issuance of at least a third-class airman medical certificate at the time of his or her most recent application (if the person has applied for a medical certificate);
(3) Not have had his or her most recently issued medical certificate (if the person has held a medical certificate) suspended or revoked or most recent Authorization for a Special Issuance of a Medical Certificate withdrawn; and
(4) Not know or have reason to know of any medical condition that would make that person unable to operate an aircraft in a safe manner.
Based on FAA medical records, the pilot’s most recent medical examination took place on February 19, 2002, in which a subsequent Second-Class Medical certificate was issued without limitations. The pilot added that he was not taking any medications at the time. There are no FAA records of the pilot reapplying for a medical certificate of any class.
The pilot’s autopsy was performed by the Josephine County Office of the Oregon State Medical Examiner, Clackamas, Oregon. According to the pilot’s autopsy report, the cause of death was massive blunt trauma due to aircraft crash, and the manner of death was accidental. Examination of the heart identified mild-to-moderate focal coronary artery disease approaching 40% narrowing. No additional anatomical details regarding the coronary artery disease were documented. The remainder of the autopsy did not identify other significant natural diseases.
The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicological tests on specimens recovered from the pilot. The pilot’s postmortem toxicological testing detected diphenhydramine in cavity blood at 140 ng/mL and in urine at 3,562 ng/mL. Gabapentin was detected in cavity blood at 8,786 ng/mL and in urine at 924,590 ng/mL. Venlafaxine was detected in cavity blood at 448 ng/mL and in urine at 12,019 ng/mL. Desmethylvenalfaxine was detected in cavity blood and urine. Amlodipine, hydrochlorothiazide, and naproxen were detected in cavity blood and liver tissue. Chlorothiazide was detected in liver tissue and was not detected in cavity blood.
Diphenhydramine is a sedating antihistamine medication widely available over the counter in multiple sleep aids and cold and allergy products. Diphenhydramine can cause cognitive and psychomotor slowing and drowsiness. It often carries a warning that it may impair performance of tasks like driving and operating heavy machinery. The FAA states that pilots should not fly within 60 hours of using diphenhydramine, to allow time for it to be cleared from circulation.
Gabapentin is a medication that is commonly used to treat nerve-related pain, and may also be used for seizures and other conditions. Gabapentin generally carries a warning that use may cause drowsiness, dizziness, and sedation. Precautions are advised for driving a vehicle or operating heavy machinery until the user can assess the impact of dosing on alertness and motor activities. Gabapentin use in adults over the age of 65 may increase the risk of decline of executive function, information processing, and motor skills. The FAA considers gabapentin a “do not issue/do not fly” medication.
Venlafaxine is a prescription antidepressant medication. Odesmethylvenalfaxine (also known as desvenlafaxine) is an active metabolite of venlafaxine and is also available as a prescription antidepressant medication. Venlafaxine has a variety of uses for depression, anxiety, nerve pain, and other conditions. Venlafaxine commonly carries a warning that it can cause drowsiness, and that users should not drive, operate heavy machinery, or do other dangerous activities until they know how the drug affects them. Caution is advised when using venlafaxine to treat depression associated with some types of bipolar disorder, as use may increase the risk of a manic episode. One small study of healthy subjects given relatively low doses of venlafaxine did not find a significant impact of venlafaxine on psychomotor and driving tests, except for some diminished performance on a test of sustained vigilance. Pilots that use venlafaxine may be considered for FAA medical certification via Special Issuance on a case-by-case basis, depending on an assessment of the underlying condition and response to treatment.
Amlodipine is a prescription medication commonly used to treat high blood pressure. Hydrochlorothiazide is a prescription diuretic that may also be used to treat high blood pressure. Chlorothiazide can be found as an impurity in hydrochlorothiazide production. Chlorothiazide is also a prescription diuretic injection, used in hospitals for congestive heart failure. Naproxen is an over-the-counter nonsteroidal anti-inflammatory medication used to treat minor to moderate pain or inflammation, and to reduce fever. Amlodipine, hydrochlorothiazide, chlorothiazide, and naproxen are not generally considered impairing.
According to the FAA’s Pilot’s Handbook of Aeronautical Knowledge, the different effects of wing planform or designs are manifested in the wing performance and airplane flight characteristics. In the case of the accident airplane, it is a regular/rectangular or a straight wing design. This design tends to stall first at the wing root, which provides adequate stall warning, adequate aileron effectiveness, and is known for stability, particularly in slow flight.
According to the airplane manufacturer, the straight-and-level stall speed is 27 mph or 23 knots. The FAA Pilot’s Handbook of Aeronautical Knowledge further states that in a 30° bank-angled turn, the stall speed increases by 10%, to about 30 mph or 26 knots; in a 40° bank-angled turn, the stall speed increases by 18%, to about 32 mph or 28 knots. An airplane that stalls while in a skid will likely roll into the turn and can often enter a spin (under the bottom), which usually manifests as an aggressive nose-low, inverted, or cross-control spin. The FAA’s Airplane Flying Handbook, Fundamentals of Stall Recovery, states that the most important action to an impending stall or a full stall is to reduce the angle of attack.
About This NTSB Record
This aviation event was investigated by the National Transportation Safety Board (NTSB). NTSB investigates all U.S. civil aviation accidents to determine probable cause and issue safety recommendations to prevent future accidents.