CHI05CA236

NTSB accident investigation · Yamokoski Glastar · Marcellus, MI · August 21, 2005

Accident · No injuriesData collectionFinal report
Date
August 21, 2005, 11:30 local (15:30 UTC)
Place
Marcellus, MI
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N4970YYamokoski Glastar
Weather
Visual (VMC) · Day
Status
Completed · report June 28, 2006
Report
Approved by Office Director
Parties
South Bend, IN, FSDO
FAA report
20050821024269A
Case key
62308

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

The in-flight loss of engine power during cruise for undetermined reasons and the unsuitable terrain the pilot encountered during the forced landing. A factor was the tall corn he encountered.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine powerCruise
Reason for occurrence undeterminedCause
Forced landingEmergency descent/landing
On ground/water encounter with terrain/waterEmergency landing
Terrain condition - high vegetationFactor
Unsuitable terrain or takeoff/landing/taxi area - encounteredPilot in commandCause
Terrain condition - ground
Nose overEmergency landing

Analysis

The experimental amateur-built airplane sustained substantial damage when the airplane nosed over on impact with high vegetation and terrain during a forced landing following an in-flight loss of engine power. The pilot stated, "At first sign of [decreased] power, turned in direction of nearest airport. Altitude was about [2,800 feet]. Ran fuel selector through all positions; no improvement noted. Determined nearest airport unreachable. Found empty field and directed airplane toward it. Landed short in field [with] tall corn. Aircraft slowed, nose dug in, flipped forward onto its back." An examination of the wreckage did not reveal any pre-impact anomalies.

Factual narrative

On August 21, 2005 about 1130 eastern daylight time, an experimental amateur-built Yamokoski Glastar airplane, N4970Y, sustained substantial damage when the airplane nosed over on impact with high vegetation and terrain during a forced landing following an in-flight loss of engine power near Marcellus, Michigan. The personal flight was operating under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed at the time of the accident. No flight plan was on file. The pilot reported no injuries. The flight originated from the La Porte Municipal Airport, near La Porte, Indiana, about 1100 and was en route to the Mason Jewett Field Airport, Mason, Michigan, at the time of the engine power loss.

The pilot's accident report, in part, stated:

Noted slight [decrease] in rpm. A minute later, engine began occasional

misfire. Engine continued to lose power/rpm, ran increasingly rough

until it quit another minute later.

At first sign of [decreased] power, turned in direction of nearest airport.

Altitude was about [2,800 feet]. Ran fuel selector through all positions;

no improvement noted. Determined nearest airport unreachable. Found

empty field and directed airplane toward it. Landed short in field [with]

tall corn. Aircraft slowed, nose dug in, flipped forward onto its back.

A Federal Aviation Administration inspector examined the wreckage. The examination did not reveal any pre-impact anomalies.

Aircraft

Registration
N4970Y
Reported as
Yamokoski Glastar
Category
Airplane, amateur-built
Serial number
5377
Airframe hours
613
Engine
Subaru EJ25, 165 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
William Yomokoski
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Annual · October 1, 2004 · 200 hours before
Departed
PPO · La Porte, IN
Destination
TEW · Mason, MI

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
56
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Unknown
Last flight review
July 1, 2005
Seat
Left
Flight hours
717 total · 613 in this make and model · 659 as pilot in command

Weather

Conditions
Visual (VMC) · Day
Wind
280° at 15 knots, gusting 22
Visibility
10 statute miles
Lowest ceiling
None
Temperature
79 °F, dew point 57 °F
Altimeter
30.04 inHg
Observed at
AZO

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 N4970Y · 1

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