NTSB Factual Report

HISTORY OF FLIGHT

On March 21, 2006, about 1030 Pacific standard time, an experimental/exhibition certificated Extra Flugzeugbau GMBH 300S airplane, N124X, sustained substantial damage when it collided with the ground along the edge of a runway during final approach to land at Metz Field, about 3 miles east-southeast of Greenfield, California. The airplane was being operated as a visual flight rules (VFR) local area personal flight for the purpose of aerobatic flight proficiency under Title 14, CFR Part 91, when the accident occurred. The airplane was operated by the commercial certificated pilot, the sole occupant, who received fatal injuries. Visual meteorological conditions prevailed. The flight originated at Reid-Hillview Airport, San Jose, California, about 0900, and no flight plan was filed.

A Federal Aviation Administration (FAA) airworthiness inspector, San Jose Flight Standards District Office (FSDO), San Jose, responded to the accident site. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on March 21, the inspector reported that the pilot departed San Jose and proceeded to Greenfield, which is about a 45 minute flight. The pilot then performed about 20 minutes of aerobatic flight in an aerobatic practice area near Metz Field. Witnesses told the inspector that the airplane appeared to fly a left (southeast) downwind pattern, paralleling runway 33. Near the approach end of the runway, the airplane made a right turn of about 45 degrees, away from the runway, then made a steep left turn, toward the runway. The airplane was then observed to level the wings and descend toward the ground with about a 10 degree nose-down attitude. The airplane collided with the ground in what witnesses described as a flat, level attitude with a high vertical velocity. The airplane bounced and struck the ground a second time, coming to rest within about 50 feet of the initial impact point, and about 15 degrees to the right of the runway heading. The airplane received structural damage to the wings, landing gear, and fuselage. The witnesses responded to the accident site, and pulled the pilot from the airplane.

PERSONNEL INFORMATION

The pilot held a commercial pilot certificate with an airplane single-engine land rating. The most recent first-class medical certificate was issued to the pilot on September 22, 2004, and contained no limitations.

No personal flight records were located for the pilot. The aeronautical experience listed on page 3 of this report was obtained from a review of the airmen Federal Aviation Administration (FAA) records on file in the Airman and Medical Records Center in Oklahoma City, which indicated the pilot's total aeronautical experience consisted of about 1,000 hours, of which 50 were accrued in the previous 6 months. Additionally, estimates of the pilot's aeronautical experience obtained from family members indicated his total hours as 1,500, with about 200 hours in the accident airplane make and model.

The pilot held an FAA statement of acrobatic competency for solo and formation aerobatics, issued February 4, 2006, with Level 1, unrestricted altitude limitations.

AIRCRAFT INFORMATION

Examination of the maintenance records revealed that the airplane, engine, and propeller were maintained on-condition, under Part 43, Appendix D. The most recent inspection was accomplished on March 17, 2006. At that time, the airplane had accumulated a total time in service of 1036.6 hours.

The airplane had two independent fuel systems consisting of the wing tank system, and the center and acro tank fuel system. The center tank is for use during aerobatic/inverted flight, and has a capacity of 11.1 gallons. It is connected to a 2.3 gallon acro tank. The wing tanks consist of integral space in front of the main wing spars, each with a capacity of 15.8 gallons. The center-acro fuel system is utilized for aerobatic flight, and for takeoff and landing. The wing fuel system is utilized for cruise flight. Total fuel capacity is 45.2 gallons, of which 0.5 gallon is unusable.

The aircraft was last fueled on the morning of the accident with the addition of five gallons of 100LL octane aviation fuel into each wing, and 4.8 gallons into the center tank.

METEOROLOGICAL INFORMATION

The closest weather reporting facility is Salinas, California, which is located about 28 miles west-northwest from the accident site. At 1003, a special weather observation was reporting, in part: Wind, 140 degrees (true) at 11 knots; visibility, 10 statute miles; clouds and sky condition, 2,700 feet broken 3,400 feet overcast; temperature, 46 degrees F; dew point, 43 degrees F; altimeter, 30.08 inHg.

AERODROME AND GROUND FACILITIES

Metz Field is equipped with a single runway on a 150 to 340 degree magnetic orientation. Portions of the airstrip are dirt and asphalt covered, and it is about 3,400 feet long and 50 feet wide.

WRECKAGE AND IMPACT INFORMATION

An FAA inspector from the San Jose FSDO examined the airplane at the accident site on March 21. He reported that he found wreckage debris and ground scars from the first observed point of ground contact, to the wreckage point of rest, which was about 100 feet to the right, and about 850 feet past, the approach end of the runway.

All of the airplane's major components were found at the main wreckage area. The landing gear assembly was torn off the fuselage, and was located behind the fuselage point of rest. The fuselage had upward crushing and bending along the underside of the tube frame. The wings had spanwise crushing along the lower portion of the leading edges. The flight control surfaces remained connected to their respective attach points, and continuity of the flight controls was established to the cockpit.

The left aileron was fractured and torn off the airplane about midspan. The right wing had a chordwise fracture about 12 inches inboard from the tip. The empennage appeared undamaged.

Following recovery of the airplane to a storage facility, an additional examination of the airframe and engine was conducted at Pleasant Grove, California, on April 13. The FAA inspector oversaw the examination, and the parties noted in this report participated. The examination revealed that belly of the fuselage had upward buckling and deformation. Continuity of the flight controls was confirmed.

The fuel selector was in the wing position. The center fuel tank's filler neck hose was pulled away at its upper end, from the base of the filler fitting. The acro tank was breached at an aft retainer strap. Residual fuel was found in the center and acro tanks. The right wing tank was breached, and the left wing tank was intact. No residual fuel was found in the wing tanks.

The gascolator bowl was damaged by impact. The drain fitting was broken, and the bowl was deformed. Examination of the bowl revealed sandy debris, but the screen was clean.

The engine sustained impact damage to the underside of the engine. Gear and valve train continuity, and thumb compression in each cylinder was noted when the crankshaft was rotated by hand. Examination of the interior of each engine cylinder via borescope revealed no defects. The exhaust tubes had crushing and folding that produced sharp creases that were not cracked or broken along the creases. The oil sump was fractured.

The mixture control was broken off the engine fuel servo. The mixture knob was set for full rich. The throttle linkage was connected to the fuel servo. The fuel servo inlet screen contained green leaf-like material. An induction hose was present from the servo to the cowling, but the cowling did not have an inlet screen installed.

The fuel pump was intact, and the shaft was free to turn by hand. The fuel manifold, injectors, and lines were free of contaminants, and contained residual fuel.

The upper cylinder sparks plugs were removed and exhibited no unusual combustion signatures. The magnetos produced spark at all terminals upon hand rotation.

The propeller assembly remained connected to the engine crankshaft flange. Two of the three composite/wood propeller blades were fractured and splintered about midspan. The third blade was fractured at its base.

There was no evidence of any preimpact mechanical malfunction observed during the engine examination.

MEDICAL AND PATHOLOGICAL INFORMATION

Review of the Monterey County Sheriff-Coroner's report, revealed that a coroner's investigator responded to the scene of the accident. The investigator reported finding the pilot's helmet and described it as having a crack in the rear, center portion of the helmet. He noted that the chin strap was broken.

A postmortem examination of the pilot was conducted under the authority of the Monterey County Coroner, 1414 Natividad Rd., Salinas, California, on March 22, 2006. The examination revealed that the cause of death for the pilot was attributed to a basalar skull fracture.

A toxicological examination was conducted by the FAA's Civil Aeromedical Institute (CAMI) on April 21, 2006. Diphenhydramine, an ingredient in numerous over-the-counter cold medications, was detected in the pilot's urine. Naproxen, an ingredient in over-the-counter analgesic medications, was detected in his urine and blood.

TESTS AND RESEARCH

The airplane was equipped with a Vision Microsystems Inc., engine monitoring system. This electronic display panel incorporates digital and visual data for engine rpm, manifold pressure, oil pressure and temperature, exhaust gas temperature, etc. The system has a data acquisition module that stores engine performance information. The San Jose FSDO inspector forwarded the module to the manufacturer for examination. At the time of this report, the data acquisition module has not been examined by the manufacturer. Telephone calls and email requests to the manufacturer have not been returned.

ADDITIONAL INFORMATION

The Safety Board did not take custody of the wreckage. No parts or components were retained by the Safety Board.

NTSB Probable Cause

The pilot's failure to maintain adequate airspeed during the base leg to final approach phase of a VFR landing pattern, which resulted in an inadvertent stall and an uncontrolled descent. A factor contributing to the accident was the inadvertent stall/mush.