N3956HErcoupe 415-CD · 1947

On May 15, 2020, about 1410 eastern daylight time, an Ercoupe 415-CD airplane, N3956H, was destroyed when it was involved in an accident near Rogersville, Tennessee. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight.

The pilot of the airplane was based at Hawkins County Airport (RVN), Rogersville, Tennessee, and an acquaintance of the pilot described that he would typically depart for short duration local flights in the vicinity of the airport.

A witness, whose farm was about 3 miles southwest of the airport, was outside when he saw the pilot fly over. He had seen the pilot fly over the farm in the past and described that on the day of the accident the pilot was “lower than he would normally fly, he would typically be about 1,000 ft and fly straight and level.” The pilot initially flew past the farm, then made two circles over the farm and flew back toward the airport. The witness stated that the pilot’s bank angle in the turns was steeper than normal and that, when he rolled out of the turn, the airplane wobbled a little, as if he had overcompensated. The witness noted the wind was erratic and gusty that day.

Two other witnesses, who were also pilots, stated that the airplane's engine sounded normal as it entered the traffic pattern to land at RVN. Both witnesses described seeing the airplane while it was low on final approach to the runway when the airplane suddenly banked right. One of the witnesses described the movement as very fast, as if the airplane was “snagged” to the right. The other witnesses stated that everything about the approach was normal until the airplane “clipped” the top of a tree. The witnesses then lost sight of the airplane and subsequently responded to the accident site, where they saw that the airplane had impacted the ground and that the wreckage was on fire.

The airplane’s most recent maintenance logbooks were not recovered. The last recorded airframe inspection was completed in August 2017, and the last recorded engine inspection was a 100-hour inspection in September 2019.

The airplane impacted the front yard of a residential property about 1,000 ft from the threshold of runway 25, at an elevation of 1,214 ft mean sea level (msl). The wreckage debris path was about 20 ft long and oriented on a magnetic heading of 240°. The grass surrounding the wreckage path displayed fuel blight.

Ground scars at the accident site and damage to the airplane were consistent with the airplane impacting terrain in a nose-low, left wing-low attitude. A postimpact fire consumed most of the wreckage; however, all major structural components of the airplane were located within the debris field. Flight control continuity was verified from the cockpit to all primary flight control surfaces. No crankcase anomalies were noted and oil was observed draining from the engine.

Further examination of the engine revealed it was exposed to fire and heat with associated damage throughout. The top spark plugs were removed for examination. All four plugs exhibited light sooting and normal wear when compared to a Champion Check-A-Plug chart. The magnetos were exposed to fire and heat. They were removed for testing. Due to internal heat damage, neither magneto would produce spark. The ignition harness was damaged from fire and heat and was not tested. The carburetor was broken away from the engine and held in place by control cables. The unit was burned and melted. Partial disassembly revealed that the metal float was intact and the inlet screen was clean and unobstructed. The oil tank remained attached to the engine and contained oil. The tank was crushed into the engine mount.

The engine’s crankshaft was turned through by hand using the propeller. Compression and suction were observed on all four cylinders. Camshaft continuity was confirmed. All valve springs were intact and valve action was correct.

The aluminum fixed-pitch propeller remained attached to the engine. There was heat and fire damage to the unit. One blade was relatively undamaged; there were some chordwise scrape marks on the aft surface of the blade. The other blade exhibited “s” bending, chordwise scratching, and leading edge gouges. The outer tip was heat and fire damaged with some loss of material due to melting.

The William Jenkins Forensic Center, Rogersville, Tennessee, performed an autopsy of the pilot. The pilot's cause of death was multiple blunt force injuries. In addition, moderate atherosclerotic stenosis (50%) of the left anterior descending coronary artery and the right coronary artery was identified. The pathologist reported the presence of hypertensive cardiovascular disease based on the appearance of the kidneys.

Toxicological testing performed by the FAA’s Forensic Sciences Laboratory identified diphenhydramine in femoral blood (65 ng/ml) and urine; cetirizine in femoral blood (24 ng/ml) and urine as well as tamulosin and naproxen in subclavian blood and urine.

Diphenhydramine is a sedating antihistamine used to treat allergy symptoms and as a sleep aid. It is available over the counter under the names Benadryl and Unisom. Diphenhydramine carries the following FDA warning: may impair mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving, operating heavy machinery).1 Compared to other antihistamines, diphenhydramine causes marked sedation; it is also classed as a CNS depressant and this is the rationale for its use as a sleep aid. Altered mood and impaired cognitive and psychomotor performance may also be observed. In a driving simulator study, a single dose of diphenhydramine impaired driving ability more than a blood alcohol concentration of 0.100%. The therapeutic range of diphenhydramine (range in which it is expected to cause effects) is 25 to 112 ng/ml.

Cetirizine is another sedating antihistamine, commonly marketed with the name Zyrtec. It carries a warning about drowsiness and is considered to routinely have effects between 190 and 1450 ng/ml.

Tamsulosin is a prescription medication used to treat symptoms of an enlarged prostate and is not generally considered impairing. Naproxen is an anti-inflammatory analgesic available over the counter under various names including Aleve. It is not generally considered impairing.