# NTSB LAX00LA350: Worgull Hornet, N707BD, Camp Verde, AZ, September 11, 2000 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 11, 2000, 08:30 local (15:30 UTC) - Place: Camp Verde, AZ - Coordinates: 34.480541, -111.77922 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.4805&lon=-111.7792&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report November 6, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 50329 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX00LA350 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/50329/pdf - Page: https://openairdocs.org/ntsb/LAX00LA350 ## 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. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, takeoff - initial climb - ignition system,spark plug - separation (cause) - engine assembly,cylinder - worn (cause) - In flight collision with terrain/water, emergency landing after takeoff - airport facilities,runway/landing area condition - roadway/highway (contributing factor) - object - vehicle (contributing factor) ## Analysis The airplane lost power on takeoff and landed hard during the ensuing emergency landing on a highway median. Upon examination of the engine it was noted that the forward spark plug had separated from the associated cylinder head. The cylinder head threads showed evidence of wear and appeared flattened. The pilot indicated that new spark plugs had been installed prior to the last flight and torqued to the manufacturer's recommended 110-inch pounds of pressure. He also stated that the threads on the cylinder heads are constructed of aluminum and the threaded portions of the spark plug barrels are constructed of steel. No further mechanical anomalies were noted. ## Factual narrative On September 11, 2000, at 0830 hours mountain standard time, an experimental Worgull Hornet, N707BD, experienced a loss of engine power and made a forced landing on Interstate 17 after takeoff from the Montezuma Airport, Camp Verde, Arizona. During the attempted landing, the airplane landed hard as the pilot was maneuvering to avoid obstacles. The airplane, owned and operated by the pilot under the provisions of 14 CFR Part 91, sustained substantial damage. The airline transport pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed for the personal flight. A flight plan had not been filed. The flight was originating at the time of the accident. In an interview with a Safety Board investigator, the pilot stated that a spark plug was found detached from the forward cylinder. He reported that the spark plug threads in the cylinder heads are made out of aluminum and the threaded portions of the spark plug barrels are made of steel. In the pilot's written statement to the Safety Board, he indicated that new spark plugs had been installed prior to the last flight, and that they were torqued to the manufacturer's recommendation of 110-inch pounds. He further indicated that there was deterioration of the threads inside of the cylinder head. He recommended a visual inspection of the spark plug threads and cylinder head threads during periodic spark plug removal. A Federal Aviation Administration inspector examined the airplane at the owner's facilities on September 22, 2000. He noted that the threads on both cylinders showed evidence of wear and appeared flattened. ## 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: 164 - Engines: Hirth 2706 R06EST 65 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Robert C. Worgull - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Continuous airworthiness, September 10, 2000, 1 hours before - Departed: 7E7 - Airport: 7E7, Montezuma Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: front; flight hours: 12,000 total, 164 in this make and model, 4,900 as pilot in command, 65 in the last 90 days, 8 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 145 °F, dew point 109 °F - Altimeter: 30.00 inHg - Observed at: PRC, 32 nm away ## 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 20000911011229A](https://openairdocs.org/incident/20000911011229A), Sep 11, 2000: Amtr HORNET, Camp Verde, AZ, Substantial damage. (-23) See attached pilot statement (.4) on September 11, 2000, at 0830 hours mountain standard time, an experimental worgull Hornet, N707BD, experienced a loss… ## 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 WPR10LA317](https://openairdocs.org/ntsb/WPR10LA317), Jun 28, 2010: Worgull Hornet (N707BD), Camp Verde, AZ, substantial damage. Probable cause: The in-flight separation of the exhaust clamps for an undetermined reason, which resulted in the exhaust system striking the wooden propeller. 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.