# NTSB CEN10CA525: Weber Acro Sport II, N819WW, Plum City, WI, September 5, 2010 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: September 5, 2010, 08:45 local (13:45 UTC) - Place: Plum City, WI - Coordinates: 44.693332, -92.150276 - Nearby events: https://openairdocs.org/map.md?lat=44.6933&lon=-92.1503&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Fuel exhaustion](https://openairdocs.org/ntsb-events/192) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report May 5, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Avaiation Administration - NTSB case key (mKey): 77232 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10CA525 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/77232/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=77232 - Page: https://openairdocs.org/ntsb/CEN10CA525 ## Probable cause The pilot’s improper fuel planning, which resulted in a loss of engine power due to fuel exhaustion. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Weber Wallace W ACRO SPORT II, 1 case](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=05646DR), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Terrain: rough terrain](https://openairdocs.org/ntsb-findings/03021015): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Weber Wallace W ACRO SPORT II, 1 case](https://openairdocs.org/ntsb-findings/03021015/cases.md?model=05646DR), [All aircraft, 442 cases](https://openairdocs.org/ntsb-findings/03021015/cases.md) - [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Weber Wallace W ACRO SPORT II, 1 case](https://openairdocs.org/ntsb-findings/02041510/cases.md?model=05646DR), [All aircraft, 559 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Fuel exhaustion](https://openairdocs.org/ntsb-events/192) (defining event); cases with it: [Weber Wallace W ACRO SPORT II, 1 case](https://openairdocs.org/ntsb-events/192/sequence.md?model=05646DR), [All aircraft, 804 cases](https://openairdocs.org/ntsb-events/192/sequence.md) - [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Weber Wallace W ACRO SPORT II, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=05646DR), [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: [Weber Wallace W ACRO SPORT II, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05646DR), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis According to the pilot, he departed with approximately 10 gallons of fuel onboard the experimental amateur-built airplane. About 20 minutes into the cross-country flight, the airplane's engine lost power and the pilot performed a forced landing to rolling terrain. A postaccident examination of the airplane and engine revealed no mechanical malfunctions or failures that would have precluded normal operation. Additionally, the on-scene inspection revealed that the fuel system was intact and that the fuel sight gauge indicated that the fuel level was low. ## Factual narrative The pilot indicated that the experimental amateur-built biplane lost engine power during cruise about 20 minutes into a cross-country flight. The terrain where the airplane sustained substantial damage to its lower left spar during an off field landing consisted of rolling hills. He reported that he departed with approximately 10 to 11 gallons of 100 low lead aviation gasoline. The pilot’s accident report stated the airplane remained intact following the accident. An on-scene examination of the wreckage revealed no pre-impact anomalies and the fuel system was intact. The indicated on-scene fuel level was in a red colored range on the fuel sight gauge. ## Aircraft - Registration: [N819WW](https://openairdocs.org/aircraft/N819WW), registered now, S/N 273, built 1991 (OpenAirDocs) - Reported make and model: WEBER ACRO SPORT II - Registry model: [Weber Wallace W ACRO SPORT II](https://openairdocs.org/model/weber-wallace-w-acro-sport-ii) (registry code 05646DR) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 273 - Airframe hours: 143 - Engines: LYCOMING O-320-B2A 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Stephen J. Weber - Registered owner: Wallace W. Weber - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, December 15, 2009 - Departed: 49MN, Hastings, MN - Destination: Mondovi, WI ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; injuries: minor; airline transport, flight engineer, flight instructor; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review July 23, 2010; seat: rear; flight hours: 25,000 total, 130 in this make and model, 23,000 as pilot in command, 285 in the last 90 days, 85 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 3 knots - Visibility: 7 statute miles - Lowest ceiling: 6,500 ft overcast - Temperature: 54 °F, dew point 54 °F - Altimeter: 29.92 inHg - Observed at: RGK ## 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 20100905044939A](https://openairdocs.org/incident/20100905044939A), Sep 5, 2010: Weber Walla ACRO SPORT, Plum City, WI, Substantial damage. Loss of power at cruise followed by an emergency landing that was quite hard. Damage substantial. ## Docket (1 files) The files NTSB released with the investigation on October 14, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=77232. 644 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 644 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40336860&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-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.