CEN10LA241

NTSB accident investigation · Hager Clinton Ray Vans RV-8 · Prague, OK · May 6, 2010

Accident · Minor injuriesLimited investigationFinal report
Date
May 6, 2010, 10:30 local (15:30 UTC)
Place
Prague, OK
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N127TTHager Clinton Ray Vans RV-8
Defining event
Enroute-cruise: Part(s) separation from AC
Weather
Visual (VMC) · Day
Status
Completed · report August 11, 2011
Report
Approved by Office Director
NTSB office
Central Region
Parties
FAA FSDO
FAA report
20100506033099A
Case key
75953

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 separation of a propeller blade for undetermined reasons.

Findings · 2

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.

Not determinedNot determined › Not determined · Unknown/Not determinedHager Clinton Ray VANS RV-8: 1 caseAll aircraft: 2,247 cases

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/builder of a kit-built airplane had recently installed a three-bladed, ground adjustable propeller. He said the new propeller had about 8 flight hours and five flights on it. About 30 minutes into the flight, a single propeller blade separated. Due to the vibration, the pilot shut down the engine and performed a forced landing to a field. During the landing, the airplane bounced, nosed over and became inverted. The propeller blade lost in flight was not found, and examination of the remaining propeller hub and blades did not determine the reason for the blade separation.

Factual narrative

On May 6, 2010, about 1030 central standard time, kit built RV-8 airplane, N127TT, impacted terrain during a forced landing following a the loss of a propeller blade while in cruise flight near Prague, Oklahoma. The private pilot, sole occupant, received minor injuries. The airplane sustained substantial damage during the accident. The aircraft was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The flight originated from the Prague Municipal Airport (O47), Prague, Oklahoma, at about 1000. The pilot reported that he was in cruise flight for about 30 minutes when a blade from the 3-bladed propeller separated from the airplane. Due to the vibration, he shut the engine down and pulled the nose of the airplane up to stop the prop from turning. Unable to return to the airport, he elected to conduct a forced landing in a field. During the landing, the airplane missed a fence, bounced, and then flipped over, coming to rest in the inverted position. The airplane's fuselage, left wing, and vertical stabilizer were all structurally damaged in the accident. The pilot (and aircraft builder) added that he had recently installed the propeller and the accident flight was about the fifth flight, with approximately 8 flight hours on the new propeller. The propeller was identified as a ground-adjustable, 3-bladed propeller manufactured by Props, Inc. The propeller blade lost in-flight was not located; however, the remaining part of the propeller and hub was sent to the US Forest Products Laboratory, for further examination. Without the missing propeller blade, the laboratory could not determine the reason for the separation.

Aircraft

Registration
N127TT
Reported as
Hager Clinton Ray Vans RV-8
Category
Airplane, amateur-built
Serial number
80071
Airframe hours
175
Engine
Lycoming IO-320, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Condition · September 14, 2009
Departed
Prague, OK
Destination
Prague, OK
Flight plan
Unknown

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
Minor
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, With waivers/limitations
Seat
Front
Flight hours
4,600 total · 175 in this make and model · 4,600 as pilot in command · 15 in the last 90 days · 6 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
130° at 9 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
73 °F, dew point 61 °F
Altimeter
29.82 inHg
Observed at
KSRE, 13 nm away

Docket · 7

The files NTSB released with the investigation on June 15, 2011, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.7 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.