CEN15LA235

NTSB accident investigation · Lathrop Steven A B8M · Ravenna, MI · May 1, 2015

Accident · Serious injuriesLimited investigationFinal report
Date
May 1, 2015, 12:25 local (17:25 UTC)
Place
Ravenna, MI
Injuries
1 serious
Damage
Destroyed
Phase of flight
Maneuvering
Aircraft
N5606XLathrop Steven A B8M
Defining event
Maneuvering: Controlled flight into terr/obj (CFIT)
Weather
Visual (VMC) · Day
Status
Completed · report September 11, 2018
Report
Approved by Office Director
NTSB office
Central Region
Parties
FAA FSDO
FAA report
20150501006339A
Case key
91193

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

On this page

Probable cause

A total loss of engine power due to carburetor icing.

Findings · 3

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 (reciprocating)Aircraft › Aircraft power plant · FailureLathrop Steven A B8M: 1 caseAll aircraft: 497 casesProbable cause
Temp/humidity/pressure: conducive to carburetor icingEnvironmental issues › Conditions/weather/phenomena · Effect on operationLathrop Steven A B8M: 1 caseAll aircraft: 435 casesProbable cause
Object/animal/substance: wireEnvironmental issues › Physical environment · Contributed to outcomeLathrop Steven A B8M: 1 caseAll aircraft: 588 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 private pilot of the gyrocopter stated that, after reducing engine power to descend, the engine experienced a total loss of power due to carburetor ice and that there was nowhere to land. The gyrocopter subsequently impacted 30-ft high power lines and the ground. Examination of the wreckage showed that the rotor blades were coned upward consistent with low rotor rpm at ground impact. Given the weather conditions in the area about the time of the accident, the aircraft would have been operating in conditions conducive to moderate carburetor icing at cruise power and serious icing at descent power. Thus, it is likely that the engine lost power due to carburetor icing.

Factual narrative

On May 1, 2015, about 1225 central daylight time, a homebuilt gyrocopter, N5606X, registered to the pilot/owner, was destroyed when it collided with power lines after a loss of engine power while maneuvering in the vicinity of Ravenna, Michigan. The private pilot, who was the sole occupant, sustained serious injuries. Visual meteorological conditions prevailed in the vicinity and a flight plan was not filed. The local flight was being conducted under the provisions of Federal Code of Regulations Part 91. The flight originated from Riverview, Michigan, about 1125. One witness reported that she heard a loud noise of a plane flying north. She further stated that she heard a loud booming sound and she looked up and saw black smoke. Another witness reported that he received a call from the pilot stating that he would be doing a slow fly-by in the area, about noon. The witness stated that he was outside several minutes after noon and that he heard the gyrocopter flying toward his home, looked up to the southeast, and saw the aircraft gliding toward the ground. The FAA inspector who examined the accident site and wreckage, reported that the wreckage was resting in a deep ditch on the north side of Sherman Road near the intersection of Wunsch Road in Moorland Township near Ravenna, MI. Evidence at the accident site showed that the gyrocopter had impacted 30-foot high power lines, consequently breaking two of the lines. A power line pole on the north side of Sherman Road was broken and unattached to its base. The pilot's headgear showed thermal damage to the face shield and soot was evident inside of the shield and around the face relief of the helmet, consistent with electrical arcing. The helmet was found in a ditch just west of Wunsch Road about 40 feet from the wreckage. The gyrocopter's rotor mast was broken off, about seat height. The rotor blades were coned upward consistent with low RPM and high loading. The trailing edges of the blades exhibited buckling between fasteners. One rotor blade had scuff marks on the bottom side. The other blade had buckling failure in the aft direction. One of the propeller blades of the pusher propeller was separated and was found about 50 yards beyond the wreckage. The broken blade leading edge exhibited leading edge marks consistent with contact with the broken power line wires. The Volkswagen engine appeared to be mostly intact. The crank would rotate by hand, but was limited due to adjacent impact damage. Automotive gasoline was present in the fuel filter and some gas was dripping out of the carburetor when first responders arrived. The broken ends of the power lines showed some broom straw signatures, some cut failures, and some right angle bending near the wire failures. The wires consisted of five aluminum wires wrapped about a steel core. The pilot stated on NTSB Form 6120 that as he slowed the engine to lower his altitude, he "got carb ice killing the engine [and] ran out of a place to land." The nearestweather reporting facility, located about 12 miles to the west of the accident site, reported a temperature of 16 degrees C and dew point of 4 degrees C, about 30 minutes prior to the accident. According to the Carburetor Icing Probability Chart, the aircraft would have been operating in conditions for moderate icing at cruise power and serious icing at descent power.

Aircraft

Registration
N5606X
Reported as
Lathrop Steven A B8M (NO SERIES)
Category
Gyroplane, amateur-built
Serial number
2
Built
2008
Airframe hours
400
Engine
Volkswagon, 65 horsepower, reciprocating
Damage
Destroyed
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Annual · March 10, 2015 · 3 hours before
Departed
Riverview, MI
Destination
MKG · Ravenna, MI
Airport
MKG · Muskegon County Airport
Equipment
None

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
67
Injuries
Serious
Certificate
Private
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 3, With waivers/limitations
Seat
Center
Restraint
3-point
Flight hours
500 total · 100 in this make and model · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
340° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
61 °F, dew point 39 °F
Altimeter
30.14 inHg
Observed at
MKG, 12 nm away

Docket · 7

The files NTSB released with the investigation on June 13, 2018, on NTSB’s docket system: statements, records, photos and specialists’ reports. 11.4 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.