# NTSB WPR09LA025: Naval Aircraft Factory N3N-3, N44848, Rialto, CA, October 26, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 26, 2008, 12:30 local (19:30 UTC) - Place: Rialto, CA - Coordinates: 34.12611, -117.416389 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.1261&lon=-117.4164&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report October 19, 2009 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 69359 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09LA025 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/69359/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=69359 - Page: https://openairdocs.org/ntsb/WPR09LA025 ## Probable cause A total loss of engine power during initial climb due to an interruption in fuel flow through an improperly assembled carburetor. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine fuel and control: fuel control/carburetor](https://openairdocs.org/ntsb-findings/01057322): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome ## Analysis The pilot performed a preflight inspection of the company airplane in preparation for a local area round-robin flight. After all systems appeared to function normally, the pilot took off and flew to his first intended landing site. Then, the pilot took off for the return flight. According to the pilot, during the ensuing takeoff, the "engine power output and acceleration were normal." However, upon climbing about 150 feet above the runway, "the engine smoothly lost power....The power loss felt like the throttle lever [was] being smoothly closed from takeoff power to idle. There was no engine roughness, vibration, or perceived reduced power output preceding the loss of power, and no backfiring or sputtering [was] associated with the power loss." The pilot made a forced landing in an open field ahead of the airplane. The airplane collided with vegetation during the landing rollout. A teardown examination of the airplane's carburetor was performed, and internal anomalies were found regarding its assembly. The main fuel jets were found too small for the engine application, and the mixture shaft was improperly keyed and/or out of alignment with its respective track. This anomaly likely resulted in unreliable mixture settings and an interruption of fuel flow to the engine. ## Factual narrative On October 26, 2008 about 1230 Pacific daylight time, a Naval Aircraft Factory N3N-3, N44848, experienced a total loss of engine power seconds after takeoff from runway 24 at the Rialto Municipal Airport, Rialto, California. The airplane collided with vegetation during the forced landing in an open field about 1/2-mile southwest of the airport. The airplane was substantially damaged. The commercial certificated pilot was not injured. Visual meteorological conditions prevailed during the personal flight, and no flight plan was filed. The flight was performed under the provisions of 14 Code of Federal Regulations Part 91. The pilot reported to the National Transportation Safety Board investigator that the planned round-robin flight originated about 1205 from the Flabob Airport in Riverside. In pertinent part, the pilot reported to the Safety Board investigator that he performed a preflight inspection of the airplane, which was followed by a pretakeoff inspection. The single fuselage fuel tank was full of fuel. All systems appeared to function normally, and he initiated the planned hour-long local area flight. The pilot flew to the Rialto Municipal Airport, landed, and taxied back for takeoff. The accident occurred during the pilot's attempted return flight to Flabob. According to the pilot, during the ensuing takeoff, the "engine power output and acceleration were normal." However, upon climbing about 150 feet above the runway, "the engine smoothly lost power....The power loss felt like the throttle lever [was] being smoothly closed from takeoff power to idle. There was no engine roughness, vibration, or perceived reduced power output preceding the loss of power, and no backfiring or sputtering [was] associated with the power loss." The pilot made a forced landing in a nearby field. Seconds prior to landing, the engine "momentarily and smoothly regained power" for 5 to 7 seconds. Then, it "smoothly lost power a second time, again without roughness, backfiring, or sputtering." During rollout in the field, the airplane collided with a tree, which resulted in impact damage to the wings. Several hours later, the pilot recovered the airplane from the accident site under a police escort. The pilot reported that no fuel was added to the airplane's fuel tank. The pilot reported that he started the engine following normal procedures, and he taxied the airplane for about 15 minutes from the accident landing site to the airport, whereupon its engine was shut down. A company mechanic for the airplane's owner reported to the Safety Board investigator that when the owner purchased the airplane, it was equipped with the accident carburetor. Since the company's acquisition of the airplane, no maintenance had been performed to the carburetor. The Federal Aviation Administration coordinator reported to the Safety Board investigator that the airplane's engine was externally examined, and no evidence of any mechanical malfunction was apparent. Thereafter, theairplane's carburetor was removed and a teardown examination was performed by Aero Engines, Los Angeles, California. During the teardown examination, internal assembly anomalies were found. The owner's mechanic reported that the carburetor's "main jets were [found] too small for the engine application." This model carburetor may be installed on different models of engines. Also, the accident carburetor had been improperly assembled. The mixture shaft was improperly keyed and/or out of alignment with its respective track. This anomaly may result in unreliable mixture settings. ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040) - [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470) ## Aircraft - Registration: [N44848](https://openairdocs.org/aircraft/N44848), registered now, S/N 4477, built 1941 (OpenAirDocs) - Reported make and model: NAVAL AIRCRAFT FACTORY N3N-3 - Registry model: [Naval Aircraft Factory N3N-3](https://openairdocs.org/model/naval-aircraft-factory-n3n-3) (registry code 6120202) (OpenAirDocs) - Registry engine: [Lycoming R680](https://openairdocs.org/engine/lycoming-r680) (registry code 41540, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 4477 - Airframe hours: 2713 - Engines: LYCOMING R680 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 26, 2008, 3 hours before - Departed: L67, Rialto, CA - Destination: RIR, Riverside, CA - Airport: L67, Rialto Municipal, runway 24, 4,500 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review October 8, 2007; seat: rear; flight hours: 895 total, 21 in this make and model, 767 as pilot in command, 6 in the last 90 days, 3 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 25 °F - Altimeter: 30.07 inHg - Observed at: ONT, 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 20081026851969A](https://openairdocs.org/incident/20081026851969A), Oct 26, 2008: Naval N3N3, Rialto, CA, Substantial damage. (-23) On takeoff at Rialto airport, CA, aircraft lost power, momentarily coming back on and then engine completely stalled out, no backfiring noted. Aircraft… ## Docket (3 files) The files NTSB released with the investigation on August 28, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=69359. 1.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40302850&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Statement of Mechanic (initial) (item 2, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40317817&FileExtension=.PDF&FileName=Statement%20of%20Mechanic%20(initial)-Redacted.PDF - Statement of Mechanic (follow-up) (item 3, .PDF, 82 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40317818&FileExtension=.PDF&FileName=Statement%20of%20Mechanic%20(follow-up)-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.