Parkman VARI-EZE N81EZ

Summary

On 18 December 1998 at about 15:15 local time, a Parkman VARI-EZE registered N81EZ was involved in an accident near Tucson, Arizona, United States. One person was on board and one died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

18 December 1998 at 15:15

Classification

Accident

Location

Tucson, Arizona, United States

Coordinates

32.0604, -111.4202

Aircraft

Parkman VARI-EZE

Registration

N81EZ

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX99FA052

1 person died.

The pilot's failure to attain and maintain an adequate flying airspeed during the aircraft's maiden flight, which resulted in a stall/mush condition. Also causal was the pilot/builder's decision to modify the engine and the fuel system control microchip, which resulted in detonation and a severe reduction in power output, and led directly to the pilot's inability to attain and maintain airspeed.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

This was the maiden flight in the aircraft, and during construction, the pilot made numerous design modifications to the airplane which had changed the flight and performance characteristics. Instead of the airplane's engines recommended by the designer, the pilot had installed a GM Geo Metro automobile engine, which the pilot altered by the addition of a Mitsubishi turbocharger. The pilot also altered the fuel computer chip to adjust the fuel flow, attempting to achieve a 2-gallon-per-hour consumption rate. The pilot told associates that the engine produced 78 hp at 4,800 rpm. Engine technical data showed the actual power output of the unmodified engine to be 79 hp at 6,000 rpm. Severe detonation was found in the engine during postaccident examination and it is believed that it most likely would produce only 55 percent of rated power. Following takeoff, witnesses saw the aircraft in a nose high attitude and it never achieved more than 100 feet agl. Some witnesses said the nose attitude was as high as 15 to 20 degrees just before the crash. The pilot radioed that he was having a problem and said he had to put the aircraft down. The airplane collided with a tree during the attempted forced landing and a postcrash fire consumed the wreckage.

Quoted verbatim from the NTSB record.