Accident Overview
On September 29, 2011, about 1850 Pacific daylight time, an experimental amateur-built Zivko/Poe Edge 540 aerobatic airplane, N42GP, was substantially damaged when it impacted terrain in Chualar, California. The certified private pilot, who was also the owner, received fatal injuries. The flight was conducted under 14 CFR Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed.
The airplane was based at Salinas Airport (SNS) in Salinas, California. The pilot did not contact Lockheed Martin Flight Services or the Direct User Automated Terminal System for weather or flight planning information.
Pilot Information
The 59-year-old pilot held a private pilot certificate with rotorcraft-helicopter and single- and multi-engine land airplane ratings. His most recent flight review was completed in September 2009. In July 2009, he reported to the FAA a total of 1,500 flight hours, with 60 hours in the previous 6 months. He was a competition aerobatic pilot and actively involved in his family vineyard and wine-making business.
Aircraft Information
The airplane was equipped with a Lycoming IO-540 series engine and was first registered to the pilot's family in 2009. It was purpose-designed for aerobatics. Although the airplane displayed advertisements for ethanol fuel, the pilot's son reported that the pilot used normal avgas and did not use ethanol.
Meteorological Information
The 1853 automated weather observation at SNS reported winds from 310 degrees at 9 knots, visibility 10 miles, an overcast cloud layer at 1,100 feet above ground level, temperature 18°C, dew point 14°C, and an altimeter setting of 29.92 inches of mercury. The area is subject to a marine layer cloud phenomenon, which typically moves in and out daily. At the time, SNS was affected by the marine layer, while Monterey Peninsula Airport (MRY), about 19 miles west-northwest of the accident site, reported clear skies. GPS data showed the pilot flew from SNS to his property at altitudes between 700 and 1,000 feet, which were at least initially due to the marine layer. However, the investigation could not determine sky conditions at the accident site.
Wreckage and Impact
The initial impact point was a ground scar on a dirt road adjacent to vineyard trellises. The scar measured about 20 feet long on a magnetic heading of 082 degrees. It terminated at rows of metal posts, with two posts fracture-separated and three bent over. The airplane was highly fragmented, with most wreckage entangled in trellises and grapevines. The primary debris field extended about 160 feet from impact. Items including a fuselage tube segment and propeller blade tip were found first. Nearly all wreckage was within this field, but a magneto, tailwheel, and aileron balance weight were located about 500 feet beyond and 150 feet above impact.
All major components, including control surfaces, were accounted for. Propeller damage was consistent with rotation under power. No catastrophic internal engine failures were observed. Flight control continuity was established to the extent possible given the damage. No pre-impact failures of the control system, structure, propeller, or engine were identified. Ground scars and damage indicated the airplane struck rising terrain with high forward velocity and low vertical velocity, in an upright, wings-level, near level pitch attitude.
Medical and Pathological Information
The pilot's most recent FAA third-class medical certificate was issued in July 2011 with no waivers or limitations. He reported no medical conditions and only Crestor (10 mg daily) for cholesterol. The pilot had multiple DUI convictions, the most recent in 2004, and reported them on previous medical applications except the most recent. In 2006, the FAA granted his medical certificate with a condition of complete abstinence from alcohol.
According to the pilot's son, in the three months before the accident, the pilot experienced black-outs during high-G maneuvers while practicing aerobatics, known as g-related loss of consciousness (g-LOC). Despite this, the pilot did not report it to medical personnel or stop flying. The son stated the pilot practiced aerobatics almost daily, performing only aileron rolls and Cuban Eights, which are limited-g maneuvers. The NTSB Medical Officer noted that sudden changes in cardiac work from g-loading could be a risk factor for cardiac arrhythmia.
The Monterey County Sheriff-Coroner's Office autopsy listed the cause of death as multiple blunt force injuries and noted significant atherosclerotic disease with calcification and evidence of an old posterior wall myocardial infarction. Forensic toxicology detected ethanol in the pilot's blood and tissue, with levels below impairment. Other substances found included Hydrocodone, Losartan, Rosuvastatin, Phenmetrazine, and Zolpidem. Hydrocodone carries a warning about impaired performance. None of the other substances are associated with impairment, though phendimetrazine (a metabolite) can increase blood pressure in hypertensive patients, possibly exacerbating cardiac arrhythmia risk.
Additional Data
The airplane was equipped with a Flight Data Systems GT-50 accelerometer, but it lacked non-volatile memory, so no accident data was available. A JPI EDM-730 engine monitor recorded engine parameters; data from the accident flight and two prior flights showed no anomalies, and the engine was operating at the last recorded data. A Garmin GPSMap 396 recorded position, altitude, and time; data enabled partial flight reconstruction. The GPS data showed the pilot departed SNS at 1841, arrived over his vineyard property about 3 minutes later, then performed maneuvers for about 4 minutes. These included rapid turns and steep climbs/descents. In the last 30 seconds, the airplane flew straight east at about 500 feet, then began a steep climb. The last three points indicated a climb rate over 5,000 feet per minute, a course reversal to the west, and groundspeed of 40 knots at 938 feet. These characteristics are consistent with the initial ascending portion of a loop or Cuban Eight. The last point was about 300 feet east of the initial ground impact point.