ERA14LA174

The accident flight was reportedly the pilot's first flight in the unregistered airplane. There were no witnesses to the accident; the airplane was found about 750 ft from the runway threshold on an approximate 45-degree angle from the runway. Although there were no witnesses or other recorded data available documenting the moments leading up to the accident, the location of the wreckage in relation to the runway suggested that the airplane might have been turning from the base to the final leg of the airport traffic pattern when the accident occurred. The orientation of the wreckage was consistent with the airplane having been in an aerodynamic stall/spin at impact. Postaccident examination of the airframe and engine revealed no evidence of any preimpact mechanical malfunctions or anomalies. Paperwork recovered from the pilot's home indicated that the airplane was based on a commercially available set of plans for an ultralight aircraft and that the pilot used these plans when he constructed the airplane. However, he made modifications that could have resulted in unanticipated adverse handling characteristics. Federal Aviation Administration guidance on amateur-built aircraft recommends developing a flight test plan to detect any hazardous operating characteristics and to determine the airplane's performance and operating envelope; however, no documents were located indicating that the pilot had developed or intended to perform a flight test plan.

On March 26, 2014, approximately 1700 atlantic standard time, an unregistered airplane was substantially damaged when it impacted the ground while maneuvering for landing at Patillas Airport (X64), Patillas, Puerto Rico. The airline transport pilot/builder was fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight. The flight was operated under the provisions of Title 14 Code of Federal Regulations Part 91. According to a Federal Aviation Administration (FAA) inspector, the accident flight was the pilot's first flight in the airplane. The airplane impacted the ground about 750 feet southwest of the runway 10 threshold at X64. There were no witnesses to the accident. Examination of photos from the accident site revealed that the airplane came to rest upright approximately 10 feet from a tree, which displayed several broken branches. The left aileron and the outboard portion of the left wing were separated from the airplane and came to rest under the tree. The cockpit area, right main landing gear, and right wing displayed significant aft crushing and were displaced aft, while the left wing root displayed minor damage and was displaced forward. The vertical and horizontal stabilizers, rudder, and elevators were intact and remained attached to the airframe. The engine remained attached to the airframe, and the two-bladed wooden propeller remained attached to the engine. One blade was fractured aft near the propeller hub, and was splintered and bent beneath the engine. The second blade was intact and displayed gouging along its leading edge and a crack emanating inward approximately 3 inches from its tip. Control continuity was established from the cockpit area to all flight control surfaces. The airplane was recovered to a hangar, and examination of the engine was conducted on May 6, 2014. The battery displayed a charge of 12 volts, the fuel tank contained approximately 3 gallons of fuel, and the engine oil level was full. Continuity of the fuel system was established from the fuel tank to the engine, and throttle and fuel mixture control continuity was established from the cockpit to the engine. The top spark plugs were removed, and visual inspection revealed normal wear. Visual inspection of the cylinders further revealed no anomalies. The engine crankshaft was rotated by hand at the propeller, and compression was obtained on all cylinders. The 1656 weather observation at Luis Munoz Marin International Airport (JSJ), San Juan, Puerto Rico, approximately 27 nautical miles north of the accident location, included wind from 50 degrees at 13 knots, 10 miles visibility, few clouds at 4,700 feet, temperature 29 degrees C, dew point 20 degrees C, and an altimeter setting of 30.04 inches of mercury. The airplane was a single-seat, tailwheel-equipped airplane of wood, steel tube, and fabric construction. It was powered by one 4-cylinder reciprocating automobile engine fitted with a wooden propeller.Paperwork recovered from the pilot's home indicated that the airplane's design was based on a commercially-available set of plans for an ultralight aircraft, from which the pilot constructed the airplane with several modifications. No documentation of the airplane and engine's build, modification, maintenance history, or flight test plan were located. The pilot held a commercial pilot certificate with ratings for airplane single- and multi-engine land and instrument airplane, as well as an airline transport pilot certificate with a rating for rotorcraft-helicopter. The pilot also held a repairman experimental aircraft builder certificate, issued in 2004, for a Vans Aircraft RV-8. His most recent FAA second-class medical certificate was issued in November 2013, at which time he reported 3,800 total hours of flight experience. The pilot's logbooks were not located. An autopsy was performed on the pilot by the Institute of Forensic Sciences, San Juan, Puerto Rico. The cause of death was listed as "blunt force trauma." The Federal Aviation Administration Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicological testing on the pilot, with negative results for carbon monoxide, ethanol, and drugs. FAA Advisory Circular (AC) 90-89A, Amateur-Built Aircraft and Ultralight Flight Testing Handbook, stated, "…test flying an aircraft is a critical undertaking, which should be approached with thorough planning, skill, and common sense." Chapter 1: Preparation, stated, "The most important task for an amateur-builder is to develop a comprehensive flight test plan. This plan should be individually tailored to define the aircraft's specific level of performance. It is therefore important that the entire flight test plan be developed and completed BEFORE the aircraft's first flight. The objective of a flight test plan is to determine the aircraft's controllability throughout all the maneuvers and to detect any hazardous operating characteristics or design features. This data should be used in developing a flight manual that specifies the aircraft's performance and defines its operating envelope." The advisory circular provided further guidance on preparing a plan for each phase of an amateur-built airplane's production. The areas for which guidance was provided included preparing for the airworthiness inspection, weight and balance, taxi test, flight testing, and emergency procedures. The suggested flight testing regimen was separated into 10-hour segments for the 40-plus hour flight testing requirement.