# NTSB SEA08CA184: Wheat Excalibur EX, N2505Q, Moses Lake, WA, August 18, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 18, 2008, 08:30 local (15:30 UTC) - Place: Moses Lake, WA - Coordinates: 47.190979, -119.300285 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.1910&lon=-119.3003&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 26, 2008 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 68724 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA08CA184 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/68724/pdf - Page: https://openairdocs.org/ntsb/SEA08CA184 ## Probable cause The right rudder pedal attach rivets sheared due to overload. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Flight control system: rudder control system](https://openairdocs.org/ntsb-findings/01022720): Aircraft › Aircraft systems · Capability exceeded (probable cause); cases with it: [Wheat Lawrence M EXCALIBUR EX, 1 case](https://openairdocs.org/ntsb-findings/01022720/cases.md?model=05904MX), [All aircraft, 93 cases](https://openairdocs.org/ntsb-findings/01022720/cases.md) - [Terrain: water](https://openairdocs.org/ntsb-findings/03021020): Environmental issues › Physical environment · Not specified; cases with it: [Wheat Lawrence M EXCALIBUR EX, 1 case](https://openairdocs.org/ntsb-findings/03021020/cases.md?model=05904MX), [All aircraft, 97 cases](https://openairdocs.org/ntsb-findings/03021020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Wheat Lawrence M EXCALIBUR EX, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=05904MX), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Wheat Lawrence M EXCALIBUR EX, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05904MX), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Wheat Lawrence M EXCALIBUR EX, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05904MX), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## 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](https://openairdocs.org/deregistered/N2505Q-2012-04-18), registration cancelled 2012-04-18, S/N 1106, built 2007 (OpenAirDocs) - Reported make and model: Wheat Excalibur EX - Registry model: [Wheat Lawrence M EXCALIBUR EX](https://openairdocs.org/model/wheat-lawrence-m-excalibur-ex) (registry code 05904MX) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane - Serial number: 1106 - Engines: 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 ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 41; 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 (OpenAirDocs). - [Accident 20080818843449A](https://openairdocs.org/incident/20080818843449A), Aug 18, 2008: Amtr EXCALIBUR, Moses Lake, WA, Minor damage. (-23) [privacy data omitted] departed the Moses Lake Municipal Airport with [privacy data omitted] the owner and manufacturer of the aircraft. They departed at… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.