Aviation Accident Summaries

Aviation Accident Summary FTW02LA125

Claremore, OK, USA

Aircraft #1

N16HH

Howard Harder Skybolt

Analysis

After calling the Flight Service Station to check the winds and have the aerobatic box opened, the pilot instructed the lineman to add 5 gallons of fuel to the airplane's main tank. After fueling the pilot taxied to runway 17 and departed at 1010. At 1040 the pilot called in for the winds. The lineman advised him they were 180 degrees at 18 knots with gusts to 22 knots. The pilot then made another call, but the lineman didn't understand what he said. At 1045 the lineman attempted to contact the pilot to inform him that personnel would be on the runway doing repair work. The pilot did not respond. At 1050 the lineman was notified in person by a local resident that he had observed an airplane doing maneuvers, that it went behind a tree line and he didn't see it come back up. At 1052 the lineman began an aerial search, spotting the aircraft wreckage at 1054, approximately 1,000 feet northwest of the departure end of runway 17. One witness said he observed the airplane descending straight down from about 1,000 feet above the ground with the wings rotating clockwise, impacting the ground after it went out of sight behind a row of trees. A second witness said he saw the airplane headed downward in a steep angle, loop, float for 1 second, loop again, and then go straight down. A third witness said he saw a small two-wing airplane wobble in the air, then suddenly go into a loop, and then come down and disappear below a tree line. The pilot had been under treatment for frequent and severe headaches, and had been prescribed frequent narcotic medications and anti-migraine medications as primary treatments for the condition. The most recent prescriptions for narcotic medication and anti-migraine medication were filled 3 days prior to the accident. Post-accident toxicoloty testing revealed the presence of multiple medications, including two different prescription antidepressants detected in blood and a prescription anti-anxiety medication, metabolites of a different prescription anti-anxiety medication, and a prescription narcotic detected in urine. Examination of the airframe and engine, and their logbooks, did not reveal any pre-existing anomalies which would have prevented normal operations.

Factual Information

HISTORY OF FLIGHT On April 18, 2002, approximately 1045 central daylight time, a Harder Howard Skybolt experimental amateur-built airplane, N16HH, was destroyed when it impacted terrain while maneuvering near Claremore, Oklahoma. The airplane was registered to a private individual and operated by the pilot. The airline transport pilot, sole occupant of the airplane, was fatally injured. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 CFR Part 91 personal flight. The flight originated from the Claremore Regional Airport (GCM), Claremore, Oklahoma, at 1010. In a written statement and telephone interview provided to the NTSB investigator-in-charge (IIC), an airport lineman reported that records indicate the pilot added 12.9 gallons of fuel the previous evening. There was no information available with respect to how long the pilot flew that evening. At approximately 0930 the morning of the accident the pilot arrived at the airport, worked in the office, checked the winds, and called the FAA Flight Service Station to "open the aerobatic box." After the pilot preflighted the airplane, the lineman assisted him in pulling it out of the hangar. At 1002, at the request of the pilot, the lineman added 5 gallons of fuel into the airplane's main tank. After fueling the pilot taxied to the run-up area at the end of runway 17, subsequently departing at 1010. At 1040 the pilot called in for the winds. The lineman advised him that they were 180 degrees at 18 knots with gusts to 22 knots. The pilot then made a call to Claremore Traffic, but the lineman didn't hear what he said. At 1045 a facilities repairman arrived at the airport to replace some lights in the Precision Approach Path Indicator (PAPI). The lineman then attempted to contact the pilot to advise him that the repairman would be going out on the runway, but there was no answer. The lineman then went outside to look for the aircraft but didn’t' see a plane or smoke. At 1050 a local resident came into the lineman's office to report that he saw a red plane doing maneuvers. He said it went below the tree line and he did not see it come back up. At 1052 the lineman took his own plane to search for N16HH, spotting the wreckage at 1054 approximately 1,000 feet northwest of the approach end of runway 17. At 1115 the lineman called the Federal Aviation Administration and the Flight Service Station to close the airport. Three witnesses supplied the following statements to the NTSB IIC: Witness #1 reported that he was driving down state Highway 20 when he first noticed the accident airplane, observing it in a descent going straight down from about 1,000 feet above ground level with the wings rotating in a clockwise direction. The witness stated that at the last second it appeared the airplane was trying to pull out of the dive, but then went behind some trees, estimated to be between 10 to 15 feet high. The witness said he didn't actually see it [the airplane] impact the ground because of the trees. The witness also stated that he couldn't say if the engine was running or not because the windows in his automobile were up. Witness #2 reported that he was driving on Highway 20 and saw what appeared (at a distance) to be a large remote controlled airplane. The witness said, " When I first saw it, it was headed downward at a steep angle, looped, and appeared to just float for 1 second. It then looped again and went straight down. I neither heard nor saw the propeller turning. There were trees between myself and the crash, so I didn't see it hit. I didn't hear it crash or see any smoke." Witness #3 reported that an airplane seemed to be close to the ground so he went to his door to see what it was. "I saw a small two-wing airplane, which seemed to wobble in the air and suddenly went in an upward loop, and on the downside disappeared below tree line from my point of view." According to the FAA inspector, who traveled to the accident site, the airplane impacted terrain in a slightly nose down, flat attitude, coming to rest in an upright position. The fuselage was bent and twisted, the left wing was separated, and one propeller blade was separated from the propeller hub. PERSONNEL INFORMATION At the time of the accident the pilot held an airline transport pilot certificate (ATP) with a date of issue of March 3, 1998. The certificate carried 3 type ratings and commercial pilot privileges for single engine land and helicopter aircraft. The pilot indicated on his last FAA medical certificate application, dated February 5, 2002, that he had accumulated a total of 12,700 flight hours, with 300 hours in the previous six months. METEOROLOGICAL INFORMATION At 1053, the weather reporting facility located at the Tulsa International Airport (TUL), located 20 nautical miles southwest of the accident site, reported a few clouds at 11,000 feet, wind 190 degrees at 18 knots, gust to 22 knots, temperature 75 degrees Fahrenheit, dewpoint 66 degrees Fahrenheit, and the altimeter setting of 29.95 inches of mercury. WRECKAGE AND IMPACT INFORMATION On April 24, 2002, an examination of the aircraft wreckage was conducted at the Claremore Regional Airport, Claremore, Oklahoma. In attendance were two Federal Aviation Administration (FAA) Aviation Safety Inspectors from the Oklahoma Flight Standards District Office, Oklahoma City, Oklahoma, and one representative from Teledyne Continental Motors, Mobile, Alabama. The aircraft came to rest in an upright position approximately 1,000 feet northwest of the approach end of runway 17 at the Claremore Regional Airport. There was no damage to the empennage and the tail section of the aircraft was intact. The right main gear was pushed up into the fuselage, while the left main gear was pushed outward and upward. The right upper wing panel was separated from its upper attach points. The right lower wing panel remained attached to the fuselage, but was wrinkled and resting on the ground. The left upper wing panel remained attached to the fuselage support structure and was wrinkled in several places through the length of the structure. The left lower wing panel remained attached to the fuselage and was also bent and twisted through the length of its structure. The fuselage sustained bending and twisting deformation from the rear cockpit area forward. Heavy impact damage was noted from the forward cockpit area to the forward most section of the airplane. The engine was intact with light impact damage on the bottom. The balance tube was crushed along with the intake and exhaust pipes. The right magneto was separated and held into place by the ignition harness. A dark stain was noted on the fuel manifold. All cylinders were chromed, and the rear of the engine was pushed into the firewall. The valve covers and top spark plugs were removed. The crankshaft was rotated and continuity was confirmed to all of the cylinders and to the rear of the engine. Compression was noted in all of the cylinders. The fuel metering unit was damaged. The throttle control was connected and exhibited freedom of movement. The mixture control was destroyed. The fuel screen was clean and clear, with a very small amount of debris on the screen. The fuel pump was intact and not damaged. The drive coupling was not damaged. The unit was free to rotate and fuel was found in the fuel lines. The low pressure set screw was separated. The fuel manifold was intact with the top of the unit exhibiting a fuel stain. The safety wire and lead seal were in place. The unit was disassembled and the diaphragm and spring were in place and not damaged. The fuel screen was clean and clear and no fuel was found in the interior. The top spark plugs had light wear and light deposits in the electrode areas. The left and right magnetos had light impact damage and both sparked at all terminals when hand rotated. The propeller spinner was bent, twisted, and exhibited aft crushing. The propeller remained attached to the propeller shaft. One propeller blade was twisted toward the direction of rotation. It was separated 18 inches outboard of the hub. Chordwise scaring was noted on the outboard section of the blade. The second blade was not damaged. MEDICAL AND PATHOLOGICAL INFORMATION Medical records obtained on the pilot document a history of severe headaches since at least 1992 treated with multiple narcotic medications and anti-migraine medications from several different providers up through the date of the accident. Applications for Airman Medical Certificate submitted to the FAA every 6 months on the pilot during this period notes the use of narcotics only once and, on 6 applications during this time, indicates no history of frequent or severe headaches. Personal medical records indicate that the headaches occurred as often as every day and document the prescription of hundreds of doses of narcotic medications each year from 1993 through the date of the accident. The most recent prescription for narcotic medication (Lortab 7.5/500 - 30 tablets) and the most recent prescription for anti-migraine medication (Imitrex 50 mg - 18 tablets) were filled 3 days prior to the accident. An autopsy was performed by the Board of Medicolegal Investigations, Office of the Chief Medical Examiner, Tulsa, Oklahoma, on April 19, 2002. According to the autopsy report, the pilot's cause of death was blunt trauma of the neck and chest. Toxicology samples were sent to the Federal Aviation Administration Civil Aeromedical Institute in Oklahoma City, Oklahoma, for analysis. The report indicated the following results: No Cyanide detected in the blood. No Ethanol detected in the urine. No Carbon Monoxide detected in the blood. 37.4 (ug/ml, ug/g) Acetaminophen detected in Urine 0.22 (ug/ml, ug/g) Alprazolam detected in Urine 0.503 (ug/mL, ug/g) Alpha-Hydroxyalprazolam detected in Urine Citalopram detected in Blood Citalopram detected in Urine 0.409 (ug/mL, ug/g) Desmethylvenlafaxine detected in Blood Desmethylvenlafaxine present in the Urine 1.794 (ug/ml, ug/g) Hydrocodone detected in Urine 0.369 (ug/mL, ug/g) Hydromorphone detected in Urine 0.044 ug/ml, ug/g) Nordiazepam detected in Blood Nordiazepam detected in Urine 0.363 (ug/ml, ug/g) Oxazepam detected in Urine 0.106 (ug/ml, ug/g) Venlafaxine detected in Blood Venlafaxine present in Urine Opiates not detected in Blood Acetaminophen is a painkiller/fever reducer often known by the trade name Tylenol, and a component of Lortab, a prescription pain reliever which also contains hydrocodone. Hydrocodone is a prescription narcotic painkiller, and hydromorphone may be produced through the metabolism of hydrocodone. Alprazolam is a prescription anti-anxiety medication commonly known by the trade name Xanax. Alpha-Hydroxyalprazolam is a metabolite of alprazolam. Citalopram (also known by the trade name Celexa) and venlafaxine (also known by the trade name Effexor) are prescription antidepressants. Desmethylvenlavaxine is a metabolite of venlafaxine. Nordiazepam is the primary metabolite of diazepam, a prescription anti-anxiety medication often known by the trade name Valium. Oxazepam is produced by additional metabolism of nordiazepam. ADDITIONAL INFORMATION The wreckage was released to United States Aviation Underwriters, Addison, Texas, on April 29, 2002.

Probable Cause and Findings

The failure of the pilot to maintain clearance with terrain for undetermined reasons while conducting aerobatic maneuvers. A factor contributing to the accident was the physical impairment of the pilot.

 

Source: NTSB Aviation Accident Database

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