# NTSB LAX03LA110: Kolb Firestar, N670JW, San Diego, CA, March 8, 2003 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 8, 2003, 10:45 local (18:45 UTC) - Place: San Diego, CA - Coordinates: 32.586944, -117.097778 - Nearby events: https://openairdocs.org/map.md?lat=32.5869&lon=-117.0978&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 1, 2004 - Report: Approved by Office Director - Parties: Federal Aviation Administration, Powerfin - NTSB case key (mKey): 56623 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX03LA110 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/56623/pdf - Page: https://openairdocs.org/ntsb/LAX03LA110 ## Probable cause propeller delamination due to the pilot's failure to properly secure the rear seat shoulder harness prior to flight. A contributing factor was the soft ground in which the airplane landed. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Propeller failure/malfunction, cruise - propeller system/accessories,blade - foreign object damage (cause) - propeller system/accessories,blade - delamination (cause) - aircraft preflight - inadequate, pilot in command (cause) - shoulder harness - uncontrolled, pilot in command (cause) - Forced landing, emergency landing - Nose over, landing - roll - terrain condition - soft (contributing factor) ## Analysis The airplane nosed over following an emergency landing in an open field. The pilot was flying westward toward the coastline at 1,500 feet. He heard a "bang," and then felt abnormal vibrations. He elected to perform an emergency landing in an open field. Upon landing in the soft ground the airplane nosed over. Initial inspection revealed a splintered propeller. The manufacturer's examination of the carbon fiber composite propeller revealed numerous indentations on the leading edges and patterns consistent with a foreign object strike that occurred prior to blade delamination. The manufacturer identified a 1.9-inch-wide abrasion mark along the entire blade width that resembled patterns that are commonly associated with nylon safety belt webbing. The aircraft kit manufacturer reported that the standard harness webbing provided by them is 1.75 inches wide. The pilot said that the rear seat of the airplane had the standard factory supplied 3-point harness webbing and the pilot seat had an after market 4-point harness. The airplane is a high wing design, with the wing mounted above and behind the open cockpit. The engine and pusher propeller are mounted on top of the wing. ## Factual narrative On March 8, 2003, at 1045 Pacific standard time, an experimental Kolb Firestar, N670JW, made an emergency landing in an open field approximately 6 miles west of Brown Field Municipal Airport, San Diego, California. The emergency landing was precipitated by a sudden onset of "abnormal vibrations." The airplane was operated by the pilot/owner under the provisions of 14 CFR Part 91, and sustained substantial damage. The private pilot and one passenger were not injured. Visual meteorological conditions prevailed for the local area flight and no flight plan had been filed. The flight originated at Brown Field at 1035. The pilot stated in the Pilot/Operator Accident Report (NTSB Form 6120.1/2), that while flying westward towards the coastline, at 1,500 feet mean sea level, he heard a "bang," followed by vibration. He elected to perform an emergency landing in an open field. Upon landing in soft ground the airplane pitched nose down and came to rest inverted. The pilot's initial inspection revealed a "splintered" propeller, vertical stabilizer damage, and damage to the right "aileron tube." He did not recall any object flying into the propeller arc during the flight or any object striking the propeller at any time prior to the accident flight. The two carbon fiber composite propeller blades separated from the hub and were retained by a Federal Aviation Administration (FAA) Inspector. He sent them to be inspected by the manufacturer under the supervision of the FAA and National Transportation Safety Board. After being examined by the manufacturer, the FAA sent the propeller to the Safety Board investigator-in-charge (IIC). Inspection of the propeller revealed two separate blades with dissimilar damage. The first blade (blade 1) was split in half along the leading edge thru the center to the trailing edge and fit together like a sandwich. Foam core material was attached to the inside of each blade half. Seven inches from the blade tip was a distinct 1.875-inch-wide abrasion mark that ran parallel to the blade chord on the uncambered side for the width of the blade. The 1.875-inch-wide mark exhibited a pattern of narrow parallel lines embedded into the erosion strip on the leading edge. When the two sides of the blade are fitted together a single 1.875-inch indentation can be identified on the leading edge at the 1.875-inch-wide abrasion mark location. The second blade (blade 2) fractured completely in two pieces with the fracture location approximately 6 inches from the blade-hub attachment base location. The fracture line ran roughly parallel to the chord line of the blade. On the blade-hub attachment barrel location there was a score line scribed on the trailing edge side. The score line was 2.25 inches in length along the circumference of the barrel and 2.25 inches from the propeller blade base. Approximately 16 inches from the blade tip there was a 0.5-inch indentation on the leading edge. The pilot-owner said that the propeller had a total operational time of approximately 12 hours on it at the time of the accident. The manufacturer's examination of the carbon fiber composite propeller revealed numerous indentations on the leading edges and patterns consistent with a foreign object strike prior to blade delamination and subsequent vibration. The manufacturer identified a 1.9-inch-wide abrasion mark along the entire blade width that resembled patterns that are commonly associated with nylon safety-belt webbing. The New Kolb Aircraft Company told the IIC that the standard harness webbing provided by them is 1.75 inches wide. The pilot said that the rear seat of the airplane had the standard Kolb 3-point harness webbing and the pilot seat had an after market 4-point harness. The airplane is a high wing design, with the wing mounted above and behind the open cockpit. The engine and pusher propeller are mounted on top of the wing. ## Aircraft - Registration: [N670JW](https://openairdocs.org/deregistered/N670JW-2005-02-11), registration cancelled 2005-02-11, S/N FS670, built 1998 (OpenAirDocs) - Reported make and model: Kolb Company Firestar - Registry model: [Wood John KOLB FIRESTAR](https://openairdocs.org/model/wood-john-kolb-firestar) (registry code 05606ZD) (OpenAirDocs) - Registry engine: [Bombardier ROTAX (ALL)](https://openairdocs.org/engine/bombardier-rotax-all) (registry code 09050, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 670 - Airframe hours: 250 - Engines: Rotax 503 52 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: John Wood - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, January 1, 2003, 11 hours before - Departed: KSDM, San Diego, CA - Destination: KSDM ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: none; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; last flight review November 27, 2001; seat: center; flight hours: 387 total, 248 in this make and model, 260 as pilot in command, 12 in the last 90 days, 6 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 4 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 48 °F - Altimeter: 30.10 inHg - Observed at: KSDM, 6 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 20030308014349A](https://openairdocs.org/incident/20030308014349A), Mar 8, 2003: Amtr FIRESTAR, San Diego, CA, Substantial damage. (-23) On March 8, 2003, N670JW, an amateur built aircraft model kolb Firestar, made an emergency landing in an open field approximately 6 miles west of brown… 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.