# NTSB LAX99LA157: Schweizer G-164B, N3633B, Marysville, CA, April 19, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 19, 1999, 07:52 local (14:52 UTC) - Place: Marysville, CA - Location: 39.1515° N, 121.5834° W: Placed by OpenAirDocs: center of Marysville, CA, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=39.1515&lon=-121.5834&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 March 2, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 46141 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX99LA157 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46141/pdf - Page: https://openairdocs.org/ntsb/LAX99LA157 ## Probable cause A loss of engine power due to a leaking surge bleed valve which induced compressor stalls within the engine. ## 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 - bleed air system,valve - leak (cause) - compressor assembly - flow restricted (cause) - turbine assembly,turbine blade - failure,total (cause) - turboshaft engine,free(power) turbine - output low - Forced landing, emergency landing after takeoff - In flight collision with object, emergency landing after takeoff - object - wire,transmission ## Analysis The pilot said that he had just taken off from a farm airstrip and was initiating a turn to clear a building when several 'pop' sounds came from the engine and it began to lose power. The pilot was unable to clear a set of power lines and struck the wires. Ground witnesses said they watched the aircraft liftoff from the airstrip and begin a gentle left turn to clear a building. In the turn a trail of black smoke began coming from the aircraft as it started a shallow descent toward a field. Just before the aircraft hit the power lines, a large puff of black smoke emanated from the aircraft. After colliding with the wires, the aircraft hit the ground and nosed over. The witnesses heard distinct 'popping sounds' associated with the onset of the smoke trail. The engine was removed and transported to a turbine engine overhaul facility for examination. Teardown of the engine revealed that one blade in the power turbine wheel had failed at the root section and was not recovered. Two other blades were fractured at their approximate midspan point and the outboard blade sections were not recovered. All other blades around the disk exhibited nicks and gouges in the leading edges. All fracture surfaces exhibited granular features. The compressor bleed valve would not hold pressure and was found to be leaking from the seal under the seal support plate-securing nut. Review of the engine maintenance records disclosed that the compressor bleed valve was installed on the engine 605 hours prior to the accident. Prior to installation on the engine, a new diaphragm was installed in the valve. ## Factual narrative On April 19, 1999, at 0752 hours Pacific daylight time, a Schweizer G-164B, N3633B, collided with power lines following a power loss during the takeoff initial climb from a private farm airstrip near Marysville, California. The aircraft was owned and operated by Onstott Dusters, Inc., of Yuba City, California, under 14 CFR Part 137 of the Federal Aviation Regulations. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local area aerial application flight. The aircraft sustained substantial damage. The commercial pilot, the sole occupant, was not injured. The flight was originating at the time of the accident and was loaded with 1,800 pounds of fertilizer to be applied to a neighboring field. In verbal and written statements, the pilot reported that he had just taken off from the airstrip and was initiating a turn to clear a building when several "pop" sounds came from the engine and it began to loose power. The pilot was unable to clear a set of power lines and struck the wires. A Yuba County road crew was working on a road close to the accident site and witnessed the accident. The workers said they watched the aircraft liftoff from the airstrip and begin a gentle left turn to clear a building. In the turn, the workers saw a trail of black smoke begin coming from the aircraft as it started a shallow descent toward a field, which is across the road. Just before the aircraft hit the power lines, a large puff of black smoke emanated from the aircraft. After colliding with the wires, the aircraft hit the ground and nosed over. The witnesses said they heard distinct "popping" sounds associated with the onset of the smoke trail. The power lines contacted by the aircraft were strung between telephone-type poles and were about 25 feet above the ground. Following recovery of the airplane from the site, the engine was removed and transported to a turbine engine overhaul facility for examination under the supervision of an Federal Aviation Administration Airworthiness Inspector from the Sacramento, California, Flight Standards District Office. Teardown of the engine revealed that one blade in the power turbine wheel had failed at the root section and was not recovered. Two other blades were fractured at their approximate midspan point and the outboard blade sections were not recovered. All other blades around the disk exhibited nicks and gouges in the leading edges. All fracture surfaces exhibited granular features. The compressor bleed valve was installed in a calibrated test bench for a functional test. The unit would not hold pressure and was found to be leaking from the seal under the seal support plate-securing nut. The fuel control unit and engine driven fuel pump functioned to specification. Review of the engine maintenance records disclosed that the compressor bleed valve was installed on the engine on March 9, 1998, 605 hours prior to the accident. Prior to installation on the engine, a new diaphragm was installed in the valve. ## Aircraft - Registration: N3633B (not matched to a registry record) - Reported make and model: Schweizer G-164B - Category: Airplane - Serial number: 775B - Airframe hours: 8199 - Engines: P&W PT6A-20 550 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Onstott Dusters, Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, February 25, 1999, 29 hours before - Airport: Farm Airstrip ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 69; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 17,900 total, 12,000 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 10 knots - Visibility: 45 statute miles - Lowest ceiling: 25,000 ft broken - Temperature: 54 °F, dew point 48 °F - Altimeter: 30.00 inHg - Observed at: MYV, 10 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 19990419044599A](https://openairdocs.org/incident/19990419044599A), Apr 19, 1999: Scwzer G164B, Marysville, CA, Substantial damage. (-23) During takeoff pilot reported hearing several pop sounds coming from engine followed by engine power loss. As a result aircraft collided with electrical… 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.