WPR09LA052

NTSB accident investigation · Adkins Ridge Runner II · Mulino, OR · November 29, 2008

Accident · Serious injuriesLimited investigationFinal report
Date
November 29, 2008, 12:36 local (20:36 UTC)
Place
Mulino, OR
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N825PBAdkins Ridge Runner II
Defining event
Initial climb: Loss of control in flight
Weather
Visual (VMC) · Day
Status
Completed · report May 12, 2009
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
Federal Aviation Administration
FAA report
20081129852939A
Case key
69515

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The pilot's failure to attain an adequate airspeed that resulted in a stall/mush during the initial climb. Contributing to the accident were the pilot's lack of experience in this make and model airplane and the improper adjustment of the propeller pitch.

Findings · 5

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Propeller system: propeller assemblyAircraft › Aircraft propeller/rotor · Incorrect service/maintenanceAdkins David Earl RIDGE RUNNER II: 1 caseAll aircraft: 29 casesProbable cause
Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedAdkins David Earl RIDGE RUNNER II: 1 caseAll aircraft: 1,681 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The pilot had recently purchased the amateur-built experimental airplane and received operating limitations from the Federal Aviation Administration for flight testing of the airplane. On the day of the accident, the pilot first performed taxi tests and then began taking off, climbing to about 10 feet above the ground, reducing power and landing back on the runway. The pilot completed a few of these runs and then taxied back onto the runway for another run. He advanced the throttle and noted that the tachometer only went to 4,000 rpm. The airplane lifted off the runway and climbed to about 150 feet above the ground. The pilot said it would not "climb higher or speed up." The airspeed was reading about 45 to 50 knots. The pilot started looking for a place to land and seeing obstacles ahead and to the left, he executed a shallow right turn back towards the airfield. The airplane stalled without notice and the pilot was not able to recover prior to ground impact. The airplane came to rest in a nose down position in a flat grassy field. The engine was displaced rearward, and the forward portion of the fuselage was crushed and compressed aft. The pilot reported that he had accumulated 240.7 hours total flight time of which 0 hours were in the accident make and model airplane. Following the accident, the propeller was found to be in "high pitch preventing the engine from turning up to more than 4,000 rpm, limiting the horsepower."

Factual narrative

On November 29, 2008, about 1236 Pacific standard time, an Adkins Ridge Runner II amateur-built experimental airplane, N825PB, impacted terrain following a loss of control during initial climb after takeoff from runway 32 at Portland-Mulino Airport, Mulino, Oregon. The private pilot, the sole occupant, received serious injuries. The airplane, which was owned and operated by the pilot, sustained substantial damage. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight operated under 14 Code of Federal Regulations Part 91. The flight was originating when the accident occurred. A witness, who was the pilot's uncle and held an Airframe & Powerplant (A&P) mechanic's certificate, reported that the pilot had recently purchased the airplane in Idaho and moved it to Oregon by ground transport. The pilot applied for, and received, operating limitations from the Federal Aviation Administration (FAA) for flight testing of the airplane. On the day of the accident, the pilot first performed taxi tests and then began taking off, climbing to about 10 feet above the ground, reducing power and landing back on the runway. The pilot completed a few of these runs and then taxied back onto the runway for another run, but did not reduce power after getting airborne. The witness reported that the airplane climbed to about 75 to 100 feet above the ground and flew pass the end of the runway. It was flying "very slow." Then the pilot banked the airplane "for a right hand turn to return to the runway." When the bank angle reached about 30 degrees, the wing "suddenly dropped" and "as the wing dropped, the nose of the aircraft dropped also." Within 1 to 2 seconds the airplane hit the ground. The pilot reported that he taxied onto the runway "for taxi test and possible take off." He advanced the throttle and noted that the tachometer "only went to 4,000 rpm." The airplane lifted off the runway and climbed to about 150 feet above the ground. It would not "climb higher or speed up." The airspeed was reading about 45 to 50 knots. The pilot "started looking for a place to land" and seeing obstacles ahead and to the left, he executed a "shallow right turn back towards the airfield." The airplane stalled "without notice" and there was not "any time or space to recover." Review of photos of the airplane at the accident site taken by local authorities revealed that the airplane came to rest in a nose down position in a flat grassy field. The engine was displaced rearward, and the forward portion of the fuselage was crushed and compressed aft. Both wings displayed skin wrinkles. The pilot reported that he had accumulated 240.7 hours total flight time of which 0 hours were in the accident make and model airplane. Following the accident, the mechanic examined the wreckage and found that the propeller was in "high pitch preventing the engine from turning up to more than 4,000 rpm, limiting the horsepower." The mechanic also reported thatthe accuracy of the airspeed indicator had not been checked, and "it may have been in error."

Aircraft

Registration
N825PB
Reported as
Adkins Ridge Runner II
Category
Airplane, amateur-built
Serial number
722811
Airframe hours
8
Engine
Rotax 503DCDI, 52 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Condition · August 31, 2008
Departed
4S9 · Mulino, OR
Destination
4S9 · Mulino, OR
Airport
4S9 · Portland-Mulino, runway 32, 3,425 × 100 ft, asphalt

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
30
Injuries
Serious
Certificate
Private
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
November 18, 2006
Seat
Single
Flight hours
241 total · 180 as pilot in command · 13 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
210° at 4 knots
Visibility
10 statute miles
Lowest ceiling
2,000 ft overcast
Temperature
57 °F, dew point 52 °F
Altimeter
30.43 inHg
Observed at
UAO, 8 nm away

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.

Other investigations on N825PB · 1

Matched to the same aircraft by N-number and date.