# NTSB CEN10LA008: Crawford Alan R Glasair II, N550AC, San Saba, TX, October 3, 2009 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: October 3, 2009, 15:15 local (20:15 UTC) - Place: San Saba, TX - Coordinates: 31.301666, -98.537223 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=31.3017&lon=-98.5372&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report April 19, 2010 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 74865 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10LA008 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74865/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74865 - Page: https://openairdocs.org/ntsb/CEN10LA008 ## Probable cause A partial loss of engine power for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Power plant](https://openairdocs.org/ntsb-findings/01057100): Aircraft › Aircraft power plant · Malfunction (probable cause); cases with it: [Crawford Alan R GLASAIR II-RG, 1 case](https://openairdocs.org/ntsb-findings/01057100/cases.md?model=05619KG), [All aircraft, 198 cases](https://openairdocs.org/ntsb-findings/01057100/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Crawford Alan R GLASAIR II-RG, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=05619KG), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Crawford Alan R GLASAIR II-RG, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=05619KG), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Crawford Alan R GLASAIR II-RG, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=05619KG), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Crawford Alan R GLASAIR II-RG, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05619KG), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis While approaching the initial approach fix (IAF), in instrument conditions and heavy rain, the airplane's engine experienced a partial loss of power. Unable to maintain altitude, the pilot declared an emergency and established a descent at best glide speed. Once below the 1,000-foot ceiling, the pilot secured the engine and performed an emergency landing on rolling terrain among mesquite trees and cacti. The airplane came to rest on its left side with the firewall and engine separated from the fuselage. The pilot was able to exit the airplane unassisted. Following the accident, the airplane was recovered to a secure hangar and examined. No preimpact anomalies were identified during the examination that contributed to the partial loss of engine power. ## Factual narrative On October 3, 2009, about 1515 central daylight time, a single engine Crawford Alan R Glasair II amateur built airplane, N550AC, was substantially damaged during a forced landing following a partial loss of engine power near San Saba, Texas. The pilot, the sole occupant, sustained minor injuries. The airplane was registered to and operated by the pilot. Instrument meteorological conditions prevailed and an instrument flight rules flight plan (IFR) was filed for the 14 Code of Federal Regulations Part 91 personal flight. The cross country flight originated from the Bridgeport Municipal Airport (XBP), Bridgeport, Texas, at 1430, and was en route to the Llano Municipal Airport (AQO), Llano, Texas. According to the pilot, both of the airplane’s main fuel tanks were "topped off" prior to departure. Approximately 45 minutes into the flight and while approaching the AQO initial approach fix (IAF), in instrument conditions and heavy rain, the airplane's engine started to run "extremely rough." Unable to maintain altitude, the pilot declared an emergency and established a descent at best glide speed. Once below the 1,000 foot ceiling the pilot "secured" the engine and performed an emergency landing on rolling terrain among mesquite trees and cacti. The airplane came to rest on its left side with the firewall and engine separated from the fuselage. The pilot was able to exit the airplane unassisted. Following the accident the airplane was recovered to a secure hangar and the engine placed on an engine stand for examination by an airframe and powerplant (A&P) certificated mechanic. According to the airplane's records, the Superior XP-IO-360 four cylinder engine had accumulated approximately 462 hours since new and around 10 hours since its last conditional inspection. The valve covers were removed and continuity was established throughout the engine. Both magnetos produced spark when turned. Compression was established in two of the four cylinders. An examination of the two leaking cylinders revealed tree debris holding the valves in an open position. The fuel screen was found unobstructed. The oil filter was cut opened and no abnormalities were found. The reason for the reported partial loss of engine power was not determined. ## Aircraft - Registration: [N550AC](https://openairdocs.org/deregistered/N550AC-2009-12-02), registration cancelled 2009-12-02, S/N 2459, built 2005 (OpenAirDocs) - Reported make and model: CRAWFORD ALAN R GLASAIR II - Registry model: [Crawford Alan R GLASAIR II-RG](https://openairdocs.org/model/crawford-alan-r-glasair-ii-rg) (registry code 05619KG) (OpenAirDocs) - Registry engine: [Superior IO-360 series](https://openairdocs.org/engine/superior-io-360-series) (registry code 59251, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 2459 - Airframe hours: 462 - Engines: SUPERIOR XP-IO-360 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, September 28, 2009 - Departed: XBP, Bridgeport, TX - Destination: AQO, Llano, TX - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; injuries: minor; flight instructor, airline transport, commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review October 15, 2008; seat: left; flight hours: 27,790 total, 500 in this make and model, 27,500 as pilot in command, 285 in the last 90 days, 95 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Instrument (IMC), Day - Wind: 170° at 10 knots - Visibility: 5 statute miles - Lowest ceiling: 1,000 ft overcast - Temperature: 66 °F, dew point 64 °F - Altimeter: 29.87 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 20091003053739A](https://openairdocs.org/incident/20091003053739A), Oct 3, 2009: Crawford Al GLASAIR II-, San Saba, TX, Substantial damage. Pilot took off from refueling point ATT67. Thirty minutes into the flight pilot experienced power loss. Switched air source and had no effect. Due to weather,… ## Docket (3 files) The files NTSB released with the investigation on January 11, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74865. 2.6 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 616 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40321739&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation (item 2, .PDF, 19 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40323588&FileExtension=.PDF&FileName=Record%20of%20Conversation-Redacted.PDF - Digital Photo 1, Right side view (item 3, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40321740&FileExtension=.PDF&FileName=Digital%20Photo%201,%20Right%20side%20view-Master.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.