NTSB Factual Report

HISTORY OF FLIGHT

On April 14, 2013, about 0815 eastern daylight time, an experimental amateur-built Kit Fox IV 1200, N117S, was substantially damaged when it impacted terrain while attempting to land at Treasure Coast Airpark (FL37), Port St. Lucie, Florida. The private pilot was fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight, which was conducted under the provisions of 14 Code of Federal Regulations Part 91.

A number of witnesses saw portions of the flight, but no one saw all of it. According to some of the witnesses, the airplane took off from runway 27, turned to the north, then circled back to a left downwind for a landing on the same runway. One witness, also a pilot, noted that during the downwind leg, the airplane was "very close in" to the runway. He also noted that although the airplane had taken off in conditions that were a "little hazy," he subsequently saw it "popping through clouds" on the downwind leg until his view was blocked by a house.

Another witness stated that, as the airplane turned toward the final approach to the runway, she saw the nose drop, and that the airplane then headed "straight down" before she lost sight of it behind a tree line.

Multiple witnesses also reported hearing the engine operating at a high power level without any anomalies.

PILOT INFORMATION

The pilot, age 62, held a private pilot certificate with an airplane single engine land rating. He also held an experimental aircraft builder repairman certificate. His latest FAA third class medical certificate was issued on February 13, 2012.

The pilot's logbook indicated 691 total flight hours as of February 10, 2013, with about 570 hours in airplane make and model. A separate pad found with the wreckage indicated another 1.2 hours of flight in the accident airplane, with the last flight noted occurring on April 7, 2013.

AIRPLANE INFORMATION

The single engine, conventional landing gear (tail dragger) airplane was powered by a Rotax 912 engine. According to the airplane's maintenance logbook, the pilot completed the airplane's latest condition inspection on September 7, 20912, at Hobbs time 506.0 hours. The latest flight listed on the pad found in the accident airplane, dated April 7, 2013, indicated a Hobbs time of 521.4 hours.

METEOROLOGICAL INFORMATION

The nearest recorded weather, at Stuart, Florida, 14 nm to the east, at 0747, included scattered clouds at 1,300 feet, mist, 5 miles visibility, temperature 23 degrees C, dew point 22 degrees C, altimeter setting 29.97 inches Hg.

One witness stated that there was ground fog at the time of the accident that dissipated about 20 minutes later.

WRECKAGE INFORMATION

Local authorities reported that the airplane impacted the ground next to a busy road, and with storms and darkness anticipated, requested that it be moved prior to NTSB arrival, which was granted under the condition that extensive photographs be taken.

A site visit the next morning revealed ground scars that were consistent with the airplane initially impacting the ground nose-down. The initial impact point was characterized by a shallow crater in which a portion of a propeller blade was found the previous day. The crater was located in the vicinity of 27 degrees, 14.28 minutes north latitude, 080 degrees, 28.52 minutes west longitude, about 090 degrees, 470 feet from the runway 27 threshold.

A linear ground scar, about the length of the airplane's wing, emanated from the crater toward a heading of about 220 degrees magnetic. Another ground scar, also about the length of the airplane's wing, emanated from the crater toward a heading of about 060 degrees magnetic. There was then a lack of ground scarring, which was consistent with the airplane having bounced once before it came to rest on its nose about 25 feet, 330 degrees magnetic from the crater, heading about 110 degrees magnetic.

An examination of the wreckage at a storage facility revealed that all flight control surfaces were present. Control continuity could not be confirmed to the cockpit due to cockpit crushing.

An approximately 45-degree upward bend of the fuselage was noted just aft of the landing gear. There was also leading edge damage along the entire left wing, and fabric tears on both the upper and lower inboard sections of the right wing. Wing crush angles could not be determined due to the fabric-covered, wooden rib construction.

One of the three composite propeller blades was sheared near the hub while the next blade in rotation exhibited a chordwise fracture and leading edge scuffing and the third blade was relatively unscathed. The spinner exhibited aft and rotational deformation.

A mid 1990s-era hand-held Magellan Skyblazer XL GPS unit was recovered from the wreckage and forwarded to the NTSB Recorders Laboratory. However, data, if saved, was not retrievable.

MEDICAL AND TOXICOLOGICAL INFORMATION

An autopsy was conducted on the pilot at the Florida District 19 Medical Examiner's Office, Fort Pierce, Florida. Cause of death was determined to be "blunt trauma injuries."

Toxicology testing was subsequently performed at the FAA Civil Aerospace Medical Institute, Oklahoma City, Oklahoma.

According to the NTSB Medical Officer Factual Report:

"Toxicology testing…detected diphenhydramine in the liver and pericardial blood (0.043 ug/ml) and doxylamine in the urine, pericardial blood (0.339 ug/ml) and femoral blood (0.103 ug/ml).

Diphenhydramine is a sedating antihistamine used to treat allergy symptoms and as a sleep aid. It is available over the counter under various trade names including Benadryl and Sominex. It carries the 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 for the drug is from 0.0250 to 0.1120 ug/ml.2

Doxylamine is also a sedating antihistamine used to treat allergy symptoms and as a sleep aid. It is available over the counter under various trade names including NyQuil and Unisom. The normal therapeutic range is from 0.050 to 0.150 ug/ml and it also carries the warning – 'may impair mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving, operating heavy machinery).'"

NTSB Probable Cause

The pilot’s failure to maintain adequate airspeed during the turn to final, which resulted in an exceedance of the wing’s critical angle-of-attack and a subsequent aerodynamic stall. Contributing to the accident was the pilot’s combined use of two sedating antihistamines, which resulted in his impairment.