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ERA11LA150 · Flaglor TOM KOLB AIRCRAFT MK III

17 Feb 2011 · Stetson, ME, United States

Flaglor TOM KOLB AIRCRAFT MK III · Accident: system/component malfunction/failure (non-power) en route

From Dewitt Field - Old Town Municipal Airport (OLD) to 1BO · Dexter, ME

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Narrative check · The NTSB narrative appears to contradict this record's departure or destination. Values are shown as recorded, not corrected; compare with the narrative.

Event

NTSB case
ERA11LA150
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
0 · all aircraft and ground
Ground fatalities
Unknown
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Flaglor TOM KOLB AIRCRAFT MK III

Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N213
Operator
Batchelder Ellery D JR · private individual
Onboard fatalities
Unknown
Route Possible conflict
From Dewitt Field - Old Town Municipal Airport (OLD), Old Town, METo 1BO · Dexter, ME
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 91: General Aviation
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
En route · cruise
Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
System/component malfunction/failure (non-power)
Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
Tree(s)
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Aircraft › Aircraft propeller/rotor

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

The pilot was in cruise flight at 1,500 feet over a heavily wooded area when the airplane began to vibrate violently before sustaining a total loss of engine power. The pilot made a forced landing and the airplane collided with trees and the ground. The pilot stated that, about 30 flight hours before this accident, the airplane experienced a similar severe vibration in flight. He shut down the engine and made a successful forced landing to a nearby airport. Examination of the airplane revealed that a triangle-shaped aluminum plate on the rear of the propeller hub had cracked. The pilot installed a new propeller hub and the original propeller blades about 7 months before the accident and began flying again without any vibrations. The total hours on the propeller blades are unknown.

A postaccident examination at the accident site revealed that both carburetors had separated from the engine assembly and were hanging by their fuel lines and throttle cables. One composite propeller blade was delaminated with a large section missing. The remaining two propeller blades appeared to be intact without comparable or crash-related damage. The carburetor detachment likely caused the final engine failure and this separation was likely a consequence of the severe vibration.

Metallurgical examination of the propeller blades identified that separation of a portion of blade No. 1 initiated as a transverse fracture, originating near the trailing edge of the blade. The transverse fracture was progressive in nature, with the crack propagating in some combination of fatigue and/or stress rupture under continually applied loads. Blade No. 2 also exhibited a pattern of parallel transverse cracks on its aft side. Blade No. 3 was also visibly damaged, with significant delamination or disbonding of the woven carbon-fiber composite skin from the forward side of the blade, along with delamination at the trailing edge. Blade No. 3 also exhibited a pattern of parallel transverse cracks on its aft side. This damage was consistent with bending of the tip of the blade forward under air loading.

Probable cause

The in-flight failure of the No. 1 composite propeller blade due to fatigue, which resulted in a violent vibration, loss of engine power, and a subsequent forced landing to unsuitable terrain.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record ERA11LA150
Event ID
20110218X23600
Case number
ERA11LA150
Dataset
full-current
Source SHA-256
5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: e9524c59bba44120a0a8b9ce5e8c9ff68ec763aa03f5a5afe5a81072c20598e9; retrieved 2026-09-15T15:49:40.867Z.