CEN10LA002

NTSB accident investigation · Piper J3C-65 · Rosemount, MN · October 3, 2009

Accident · Serious injuriesLimited investigationFinal report
Date
October 3, 2009, 15:47 local (20:47 UTC)
Place
Rosemount, MN
Injuries
1 serious, 1 minor
Damage
Substantial damage
Phase of flight
Takeoff
Aircraft
N70585Piper J3C-65
Defining event
Takeoff: Loss of engine power (partial)
Weather
Visual (VMC) · Day
Status
Completed · report May 28, 2010
Report
Approved by Office Director
NTSB office
Central Region
Parties
FAA-Minneapolis FSDO
FAA report
20091003050369A
Case key
74849

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 delayed use of carburetor heat while operating in conditions conducive to carburetor icing.

Findings · 4

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.

Engine controlsAircraft › Aircraft power plant · Incorrect use/operationPiper J3C-65: 1 caseAll aircraft: 51 casesProbable cause
Action: delayed actionPersonnel issues › Action/decision · PilotPiper J3C-65: 3 casesAll aircraft: 894 casesProbable cause
Temp/humidity/pressure: conducive to carburetor icingEnvironmental issues › Conditions/weather/phenomena · Effect on operationPiper J3C-65: 8 casesAll aircraft: 435 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 reported that he started the engine and waited for about 10 minutes for the oil temperature to rise before he departed from a grass airstrip. During takeoff, he reported that the airplane “felt slow.” He turned the carburetor heat on, but the engine lost partial power and the airplane "started to sink." He banked to the left to avoid trees. He reported losing altitude, and then the airplane experienced a “stall spin to the left,” impacting a mature corn field. Postaccident inspection of the engine and airframe revealed no preexisting anomalies that would preclude normal operation of the airplane. The observed temperature was 11 degrees Celsius (C) and the dew point was 6 degrees C. The Transport Canada Carburetor Icing chart indicated that at the observed weather conditions the engine was susceptible to “Serious Icing – Any Power.”

Factual narrative

On October 3, 2009, at 1547 central daylight time, a Piper J3C-65, N70585, sustained substantial damage when it impacted terrain after a loss of engine power after takeoff from a grass airfield in Rosemount, Minnesota. The pilot received minor injuries and the front seat passenger received serious injuries. The 14 Code of Federal Regulations Part 91 personal flight was departing from Jensen Airfield, a private grass airstrip, on a local flight. Visual meteorological conditions prevailed and no flight plan was filed. The pilot reported that there was a fly-in at the private airstrip and he decided to take a friend for a flight “around the patch.” After he preflighted the airplane, he started the engine and waited for about 10 minutes for the oil temperature to rise. He taxied out and did a run-up prior to departure. During takeoff, he added power slowly to full power, got the tail up, and slowly rotated. He reported that the airplane "felt slow." He tried to land, but he was too fast and there was “not enough room.” He pulled the carburetor heat on, but the engine lost partial power and the airplane “started to sink.” He banked to the left to avoid trees. He reported losing altitude, and then the airplane experienced a “stall spin to the left.” The airplane impacted a mature corn field. The pilot shut off the airplane’s magnetos and fuel, and exited the airplane with the passenger. A Federal Aviation Administration airworthiness inspector examined the airplane. The inspection revealed that the magnetos and fuel selector were turned off. The fuel tank was ruptured. The primer was in and locked. The carburetor heat was out (on). The propeller was bent aft. The airplane was equipped with a seat belt and shoulder harness for the rear seat. The front seat was equipped with a seat belt, but no shoulder harness, although there was a hard attachment point for a shoulder harness. The flight controls exhibited cable continuity to the ailerons, elevator, and rudder. The inspection of the 65-horsepower Continental A-65-8 engine revealed that the carburetor was broken in half, top to bottom. The carburetor air box was crushed from impact forces. The spark plugs were clean and clear. The left and right magnetos produced spark. The engine was rotated and it exhibited continuity in the drive train, and there was compression on all four cylinders. At 1553, the observed weather at the Minneapolis-St Paul International Airport (MSP), located about 12 miles northwest of the accident site, was: Wind 320 degrees at 7 knots, visibility 10 miles, few clouds at 2,100 feet, broken ceiling at 3,400 feet, temperature 11 degrees Celsius (C), dew point 6 degrees C, altimeter 29.81 inches of Mercury. The Transport Canada Carburetor Icing chart indicated that “Serious Icing – Any Power” conditions existed with a temperature of 11 degrees C and a temperature dew point of 6 degrees C.

Aircraft

Registration
N70585
Reported as
Piper J3C-65
Category
Airplane
Serial number
17594
Airframe hours
2,068
Engine
Continental A-65-8, 65 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Brian B Doyle
Registered owner
Brian B Doyle
Airworthiness certificate
Standard, Normal
Last inspection
Annual · May 7, 2009
Departed
Rosemount, MN
Destination
Rosemount, MN
Airport
Jensen Airfield

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
35
Injuries
Minor
Certificates
Commercial, Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1
Last flight review
July 1, 2009
Seat
Rear
Flight hours
2,120 total · 60 in this make and model · 14 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
330° at 7 knots
Visibility
10 statute miles
Lowest ceiling
3,400 ft broken
Temperature
52 °F, dew point 43 °F
Altimeter
29.80 inHg
Observed at
MSP, 12 nm away

Docket · 3

The files NTSB released with the investigation on March 25, 2010, on NTSB’s docket system: statements, records, photos and specialists’ reports. 3.7 MB in all.

FAA reports on this event · 1

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