# NTSB WPR10LA317: Worgull Hornet, N707BD, Camp Verde, AZ, June 28, 2010 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: June 28, 2010, 08:17 local (15:17 UTC) - Place: Camp Verde, AZ - Coordinates: 34.577499, -111.880554 - Nearby events: https://openairdocs.org/map.md?lat=34.5775&lon=-111.8806&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report March 16, 2011 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA FSDO - NTSB case key (mKey): 76463 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR10LA317 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/76463/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=76463 - Page: https://openairdocs.org/ntsb/WPR10LA317 ## Probable cause The in-flight separation of the exhaust clamps for an undetermined reason, which resulted in the exhaust system striking the wooden propeller. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine exhaust](https://openairdocs.org/ntsb-findings/01057800): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Worgull Robert C HORNET, 1 case](https://openairdocs.org/ntsb-findings/01057800/cases.md?model=05606MW), [All aircraft, 56 cases](https://openairdocs.org/ntsb-findings/01057800/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Worgull Robert C HORNET, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=05606MW), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Propeller system: propeller blade section](https://openairdocs.org/ntsb-findings/01046111): Aircraft › Aircraft propeller/rotor · Damaged/degraded; cases with it: [Worgull Robert C HORNET, 1 case](https://openairdocs.org/ntsb-findings/01046111/cases.md?model=05606MW), [All aircraft, 51 cases](https://openairdocs.org/ntsb-findings/01046111/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) (defining event); cases with it: [Worgull Robert C HORNET, 1 case](https://openairdocs.org/ntsb-events/338/sequence.md?model=05606MW), [All aircraft, 563 cases](https://openairdocs.org/ntsb-events/338/sequence.md) - [Enroute-cruise: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Worgull Robert C HORNET, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05606MW), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot reported that during cruise flight, the engine made a sound akin to a “buzz saw” that required him to initiate a forced landing to a nearby field. During the landing roll the nosewheel separated and the pusher-type engine separated from the mount assembly, impacting into the cockpit area. The pilot stated that a postaccident examination of the airplane revealed that the exhaust clamps had separated from the support structure while in-flight. A section of the exhaust system then struck the wooden propeller blades. Examination of the airplane by a Federal Aviation Administration inspector revealed the both wooden propeller blades had been sheared approximately six inches outboard of the blade root. Seven of the eight engine mount bolts were sheared at the adapter plate and the eighth bolt was missing. The separated exhaust clamps were not recovered for examination. ## Factual narrative On June 28, 2010, about 0817 mountain standard time, an experimental amateur-built Worgull Hornet airplane, N707BD, sustained substantial damage following an in-flight propeller separation and subsequent emergency landing near Camp Verde, Arizona. The airline transport pilot, the sole occupant of the airplane, sustained serious injuries. The airplane is registered to the pilot and was operated as a visual flight rules (VFR) personal flight under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91. Visual meteorological conditions prevailed at the time of the accident. The flight originated from Camp Verde at 0730. No flight plan was filed for the local flight. The pilot reported that while in cruise flight, the engine began to sound like a "buzz saw" and he believed the 2-bladed wooden propeller had failed. He executed a forced landing into a nearby field. During the landing roll, the nose wheel separated and the pusher type engine separated from the mount assembly and fell into the cockpit area. The pilot reported that a postaccident examination of the airplane revealed that the exhaust bracket clamps separated (in flight) from the support structure, which resulted in a portion of the exhaust system contacting the wooden propeller. A witness stated that while in his home, he heard “banging and clanging and [an] engine running.” The witness exited his home and observed an airplane flying towards his house. The airplane flew over the house, banked towards the west and landed. Examination of the airplane by a Federal Aviation Administration inspector revealed that both blades of the wooden propeller were sheared approximately 6 inches outboard of the blade root. There was a minimal amount of wooden splinters located at the accident scene, all of which were in the fuselage below the engine. Seven of the eight engine mount bolts were sheared at the adapter plate mount and the eighth bolt was missing. ## Aircraft - Registration: [N707BD](https://openairdocs.org/deregistered/N707BD-2010-08-19), registration cancelled 2010-08-19, S/N 707, built 1998 (OpenAirDocs) - Reported make and model: WORGULL HORNET - Registry model: [Worgull Robert C HORNET](https://openairdocs.org/model/worgull-robert-c-hornet) (registry code 05606MW) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 707 - Airframe hours: 480 - Engines: Hirth 3203 65 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Worgull Robert C - Registered owner: Worgull Robert C - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, June 25, 2010, 30 hours before - Departed: Camp Verde, AZ - Destination: Camp Verde, AZ ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 80; injuries: serious; flight instructor, flight engineer, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review November 7, 2008; seat: left; flight hours: 12,500 total, 480 in this make and model, 5,000 as pilot in command, 4 in the last 90 days, 2 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Lowest ceiling: none ## 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 20100628037219A](https://openairdocs.org/incident/20100628037219A), Jun 28, 2010: Worgull Rob HORNET, Camp Verde, AZ, Substantial damage. The aircraft lost power and made an emergency landing in a nearby field. Upon touching down, the nose wheel sheared off and the engine was thrown from the back… ## Other investigations on N707BD (1) 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. - [NTSB LAX00LA350](https://openairdocs.org/ntsb/LAX00LA350), Sep 11, 2000: Worgull Hornet (N707BD), Camp Verde, AZ, substantial damage. Probable cause: Separation of the forward spark plug due to wear damage to the cylinder head threads. A factor in the accident was traffic on the highway and the pilot having to maneuver to avoid the traffic. ## Docket (2 files) The files NTSB released with the investigation on October 29, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=76463. 3.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40337431&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - FAA Inspector Statement (item 2, .PDF, 392 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40337432&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Redacted.PDF 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.