SEA08CA184

NTSB accident investigation · Wheat Excalibur EX · Moses Lake, WA · August 18, 2008

Accident · No injuriesData collectionFinal report
Date
August 18, 2008, 08:30 local (15:30 UTC)
Place
Moses Lake, WA
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N2505QWheat Excalibur EX
Defining event
Enroute-cruise: Sys/Comp malf/fail (non-power)
Weather
Visual (VMC) · Day
Status
Completed · report September 26, 2008
Report
Approved by Office Director
Parties
Federal Aviation Administration
FAA report
20080818843449A
Case key
68724

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 right rudder pedal attach rivets sheared due to overload.

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.

Terrain: waterEnvironmental issues › Physical environment · Not specifiedWheat Lawrence M EXCALIBUR EX: 1 caseAll aircraft: 97 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 was on a local, personal flight in an experimental airplane. While in cruise flight approximately 600 feet above ground level he heard a loud bang and the airplane entered a right turn. The pilot used aileron to counteract the turn; however, the airplane descended into the reservoir below. Post accident inspection showed that the rivets securing the rudder pedals had sheared in overload and there was no evidence of corrosion. During the impact sequence, the fuselage sustained structural damage. According to the kit supplier, the rudder pedal horns are secured using three rivets per pedal. The kit supplier indicated that the rivets could be put under excessive stress while operating the airplane over gross weight and/or powering the airplane with an engine that produces over 65 horsepower. The engine installed in the airframe produced 85 horsepower. As a result of the accident, the kit supplier suggested that the builders include a rudder pedal security check and if they are loose, replace two of the three rivets with two bolts. All future designs kits produced and shipped will include the bolts.

Factual narrative

The pilot was on a local, personal flight in an experimental airplane that had accumulated 32 hours total time. It was powered by an engine that produced 85 horsepower. While in cruise flight approximately 600 feet above ground level he heard a loud bang and the airplane entered a right turn. The pilot used aileron to counteract the turn; however, the airplane descended into the reservoir below. Post accident inspection showed that the rivets securing the rudder pedals had sheared. During the impact sequence, the fuselage sustained structural damage. According to the kit supplier, the rudder pedal horns are secured using three rivets per pedal. The kit supplier indicated that the rivets could be put under excessive stress while operating the airplane over gross weight and/or powering the airplane with an engine that produces over 65 horsepower. Although there had been no other reports of this kind to the kit supplier, following the accident he suggested to his customers that they check the security of the rivets prior to each flight and if they are loose, replace two of the three rivets with two bolts provided by the kit supplier. All future rudder pedals provided by the kit supplier will be equipped with the bolts.

Aircraft

Registration
N2505Q
Reported as
Wheat Excalibur EX
Category
Airplane
Serial number
1106
Engine
Jabiru 2200, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Darrin Jackson
Registered owner
Lawrence M. Wheat
Airworthiness certificate
Special, Experimental (Special)
Departed
W20 · Moses Lake, WA

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
41
Certificate
Private
Airplane ratings
Single-engine land, Multi-engine land
Medical
Class 3
Flight hours
3,126 total · 47 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
20° at 6 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
77 °F, dew point 52 °F
Altimeter
29.62 inHg

FAA reports on this event · 1

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