CEN16FA215

The pilot's failure to maintain helicopter control during takeoff. Contributing to the accident was the pilot's impairment due to his combined use of alcohol and diphenhydramine, which led to his improper decision to fly after drinking alcohol and degraded his ability to maintain control of the helicopter.

During the 2 to 3 hours before the accident, a witness saw the commercial pilot drinking from a cup that smelled like alcohol and noticed that he refilled the cup two or three times. He then heard the pilot say that he was going to put on an airshow. The helicopter lifted off at a 45° angle backward and upward, reach an altitude of about 125 ft, and then descend out of sight behind hangars. A postaccident examination revealed that the helicopter's tail contacted the ground behind the hangars resulting in separation of both tail rotor blades. The helicopter then rose above the hangars and began to spin. The helicopter descended again, impacted terrain, and burst into flames. The examination of the wreckage did not reveal evidence of any preimpact anomalies that would have precluded normal operation of the helicopter. Toxicology testing detected diphenhydramine, a sedating antihistamine, and elevated levels of ethanol in the pilot's blood and tissues. The pilot was most likely impaired by the combination of ingested alcohol and the use of diphenhydramine, both of which are central nervous system depressants. The impairing effects of the combination of these substances most likely contributed to his decision to fly after drinking alcohol as well as his inability to maintain control of the helicopter.

23AR was a private, non-towered airport, which was owned by an individual. It was located about 7 miles east of Jonesboro, Arkansas. The airport had an estimated elevation of 260 ft above mean sea level. The airport's published runway 17/35 was 2,600 ft by 80 ft with a turf surface. Another, privately-owned, north/south-oriented turf runway was located about 350 ft west of 23R's published runway. At 1538, the recorded weather at the Jonesboro Municipal Airport, near Jonesboro, Arkansas, located about 5 miles west of 23AR, included wind 090° at 4 knots, visibility 10 statute miles, present weather thunderstorms in the vicinity, temperature 34° C, dew point 21° C, and altimeter 30.02 inches of mercury. The Arkansas State Crime Lab Medical Examiner's Office conducted an autopsy on the pilot and took toxicological samples. The autopsy indicated that the pilot's cause of death was multiple blunt force injuries and the manner of death was an accident. No significant natural disease was identified during the autopsy. The FAA Bioaeronautical Sciences Research Laboratory performed toxicological testing on the samples taken during the autopsy. The toxicology report indicated that the samples sustained putrefaction and listed the following findings: 418 (mg/dL, mg/hg) Ethanol detected in Blood 336 (mg/dL, mg/hg) Ethanol detected in Heart 309 (mg/dL, mg/hg) Ethanol detected in Lung 182 (mg/dL, mg/hg) Ethanol detected in Kidney 152 (mg/dL, mg/hg) Ethanol detected in Urine ... Diphenhydramine detected in Urine 0.049 (ug/ml, ug/g) Diphenhydramine detected in Blood Pioglitazone detected in Urine Valsartan detected in Urine Valsartan detected in Blood Ethanol is the intoxicant commonly found in beer, wine, and liquor. It acts as a central nervous system (CNS) depressant. After ingestion, at low doses, it impairs judgment, psychomotor functioning, and vigilance; at higher doses it can cause coma and death. The effects of ethanol on aviators are generally well understood; it significantly impairs pilots' performance, even at very low levels. Federal Aviation Regulations prohibit any person from acting or attempting to act as a crewmember of a civil aircraft while having 0.040 gm/dl (40 mg/dl) or more ethanol in the blood. Ethanol may also be produced in the body after death by microbial activity. Diphenhydramine is a sedating antihistamine used to treat allergy symptoms and as a sleep aid. It is available over the counter under many names including 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)." The therapeutic range of diphenhydramine is 0.0250 to 0.1120 ug/ml; this is the range of blood levels where psychoactive effects are expected. Diphenhydramine undergoes postmortem redistribution where, after death, the drug can leech from storage sites back into blood. Central postmortem levels may be about two to three times higher than peripheral levels. 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%. Valsartan is a prescription blood pressure medication often marketed with the name Diovan. It is not generally considered impairing. Pioglitazone is a prescription medication for diabetes; it is often marketed with the name Actos. It is not generally considered impairing and does not lead to the development of hypoglycemia. Review of the pilot's FAA medical records indicated that he had reported no chronic medical conditions and no medication use to the FAA. The 73-year-old pilot held a Federal Aviation Administration (FAA) commercial pilot certificate with airplane single-engine land, rotorcraft helicopter, rotorcraft gyroplane, and instrument airplane ratings. He also held a flight instructor certificate, expiring October 31, 2017, with airplane single engine, rotorcraft helicopter, and rotorcraft gyroplane ratings. He held a FAA second-class medical certificate issued on May 1, 2014, with the limitations that he "must wear corrective lenses and possess glasses for near and intermediate vision." At the time of that medical examination, he reported 6,000 hours total flight time and 110 hours in the 6 months before that examination. A review of excerpts from the pilot's logbook did not reveal an entry for a flight review. The logbook pages were not totaled, and the last entry was dated August 2, 2015. N789MR, serial number 10561, was a Robinson R44 II, Raven, four-place, two-bladed, single main rotor, single-engine helicopter, with a spring and yield skid type landing gear. The primary structure of its fuselage was welded steel tubing and riveted aluminum sheet. The tailcone was a monocoque structure consisting of an aluminum skin. A Lycoming IO-540- AE1A5, serial number L-29728-48A, engine rated at 260 horsepower, powered the helicopter. However, according to the helicopter's type certificate, the engine had a 5-minute takeoff rating of 245 horsepower and a maximum continuous rating of 205 horsepower. A review of helicopter logbook excerpts that were provided by a FAA inspector, showed that the helicopter's last annual inspection was completed on July 2, 2015. At the time of that inspection, the helicopter had accumulated a total time of 1,242.1 hours. The helicopter manufacturer issued, R44 Service Bulletin (SB)-78B, on December 20, 2010, and issued a revised SB on September 28, 2012. The SB, in part, stated: TO: R44 and R44 II owners, operators, and maintenance personnel SUBJECT: Bladder Fuel Tank Retrofit ROTORCRAFT AFFECTED: R44 helicopters S/N 0001 thru 2064, and R44 II helicopters S/N 10001 thru 12890, unless previously accomplished. TIME OF COMPLIANCE: As soon as practical, but no later than 30 April 2013. BACKGROUND: This bulletin requires R44 helicopters with all-aluminum fuel tanks to be retrofitted with bladder-type tanks. In addition to a factory retrofit program, a field kit is now available. To improve the R44 fuel system's resistance to a post-accident fuel leak, this retrofit must be performed as soon as possible. The review of the helicopter logbook excerpts did not reveal an entry for the installation of the bladder fuel tanks as called for by the SB. The main helicopter wreckage was located about 1,800 ft on a magnetic heading of 35° from the intersection of Highway 18 and Barnhill Road. The turf, in a circular shaped area around the helicopter was found charred. Portions or the helicopter wreckage were discolored, deformed, and consumed by fire consistent with a ground fire. The helicopter's resting heading was about 270° magnetic. The tailcone was folded to the left and separated near its forward end. Most of the aluminum and fiberglass components of the fuselage were discolored, deformed, and consumed by fire. The separated aft section of the tailcone was located about 20 ft south of the airframe. The tail rotor gearbox remained attached to the aft bulkhead of the separated section of the tailcone. The empennage separated from the aft bulkhead and was located about 40 ft south of the airframe. The main rotor gearbox and main rotor were separated from the airframe and found about 3 ft north of the airframe. Ground scars north of the airframe were consistent with main rotor blade strikes. Main rotor blade tip pieces were recovered in and near the ground scars and yellow paint that matched the paint on the main rotor blade tips was transferred to the dirt inside the scars. Both tail rotor blades were separated near their roots and were found east of the airframe on the other side of