# NTSB WPR11FA404: Cessna 150G, N2870S, Cavanaugh Bay, ID, August 23, 2011 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Field investigation · Final report - Date: August 23, 2011, 11:38 local (18:38 UTC) - Place: Cavanaugh Bay, ID - Coordinates: 48.516109, -116.820274 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=48.5161&lon=-116.8203&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR go-around: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report December 19, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration, Cessna Aircraft Company - NTSB case key (mKey): 81583 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11FA404 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81583/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81583 - Page: https://openairdocs.org/ntsb/WPR11FA404 ## Probable cause The pilot’s failure to maintain adequate airspeed during an attempt to execute a go-around with a tailwind condition, which resulted in an aerodynamic stall and spin. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Cessna 150G, 3 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=2071816), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Cessna 150G, 3 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=2071816), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Cessna 150G, 2 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=2071816), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Cessna 150G, 17 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2071816), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR go-around: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Cessna 150G, 7 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=2071816), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 150G, 23 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2071816), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that he recalled making a normal approach to a grass strip runway with a known 8- to 10-knot tailwind, but he did not remember the accident itself. One of two witnesses reported that the airplane appeared to be flying slower than normal on final approach, and both reported seeing the airplane begin to go around and hearing the engine at high power. The airplane then pitched up into a nose high attitude and entered a rapid descent consistent with an aerodynamic stall and spin. The airplane wreckage was located 150 yards from the boundary of the grass strip, resting on its nose, with the tail oriented vertically. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. ## Factual narrative HISTORY OF FLIGHT On August 23, 2011, about 1138 Pacific daylight time, a Cessna 150G, N2870S, crashed 150 yards east of the southern running grass landing strip at Cavanaugh Bay Airport, Coolin, Idaho. The airplane's owner operated the airplane under the provisions of Title 14 Code of Federal Regulations Part 91. The private pilot was seriously injured, and the airplane was substantially damaged. Visual meteorological conditions prevailed, and no flight plan had been filed. The flight originated from Chattaroy, Washington, around 0900. Witnesses reported to a Federal Aviation Administration inspector, who responded to the scene of the accident, that they observed the airplane as it approached the grass landing strip. One witness stated that he saw the airplane's left wing dip down, then the airplane pitched up into a high angle of attack, and descended vertically; he then lost sight of it behind some trees. He could hear the engine developing high power until it contacted trees and terrain. The Cavanaugh Bay Airport is located on the southeastern side of Priest Lake. The airplane wreckage was located 150 yards east of the grass runway, among a large grove of conifer trees. The airplane was resting on its nose, with the wing leading edges parallel to the ground, and the tail buckled and skewed to the left of center. First responders reported that there was fuel leaking from the airplane, and the pilot was seriously injured with head, arm, and chest injuries. The pilot stated that he had flown into the airstrip on Cavanaugh Bay at Priest Lake about 10 times over the last 10 years. The purpose of the accident flight was recreational in nature, and he made a normal approach to the southern runway. The runway is sloped, and a landing to the south would be an upslope landing. As he made his approach he noted the wind on the water of Priest Lake, and estimated an 8- to 10-knot tail wind. Additionally, the pilot stated that there were 100-foot-tall trees at the approach end of the airstrip that make the approach and landing difficult. He could not recall his attempt to abort the approach, perform a go-around, or the crash itself. PERSONNEL INFORMATION The pilot, age 85, held a private pilot certificate for airplane single engine land issued December 18, 2003, and a third-class medical certificate issued June 16, 1994, with the limitation that he wear glasses for near vision. The pilot said that he had about 900 hours of total flight time, with the majority of that time in the Cessna 172 series, with between 30-40 hours in the accident model airplane. The pilot’s most recent flight review was conducted on July 1, 2011, in the accident airplane. AIRCRAFT INFORMAITON The two seat, high-wing, fixed landing gear airplane, serial number 15066770, was manufactured in 1967. The airplane was equipped with an Alpha Systems angle of attack (aoa) indicating system, with an aoa gauge mounted on the pilot's glare shield. The airplane was powered by a LycomingO-320-E2D, 150-hp engine and equipped with a McCauley fixed pitch propeller, model TM7456. An FAA Form 337, Major Repair and Alteration, documented that on December 8, 1986, the original Continental Motors, 100-hp, O-200 series engine was replaced with the Lycoming O-320-E2D engine. Review of the airplane maintenance logbook revealed an annual inspection was performed on November 17, 2010, at an airframe total time of 5,803 hours, and engine time since major overhaul of 2,081 hours. WRECKAGE AND IMPACT INFORMATION On September 14, 2011, the NTSB investigator-in-charge and a technical representative from Cessna Aircraft Company examined the airplane wreckage at a facility in Deer Park, Washington. The airplane’s wings had been separated from the main fuselage to facilitate wreckage transportation from the accident scene. Airplane controls were continuous from the cockpit to ailerons, elevator, and rudder though multiple cable cuts that were performed by the recovery crew. The flaps appeared to be retracted on their tracks, and the flap actuator was observed retracted. The elevator trim was measured at 1.44 inches; per the Cessna representative, 1.45 inches is neutral. The stall warning horn was clear of debris and sounded when air was passed through the horn/reed. The throttle cable remained connected from the cockpit to the carburetor. The mixture cable was connected at the cockpit, but was severed from the carburetor mixture lever. The carburetor bowl had been separated from the upper half of the carburetor body; the brass floats were mechanically damaged and crushed. The top, Champion REM37BY, were removed. All gaps were measured to be greater than 0.016 inches, and all exhibited a light gray coloration, as well as wear signatures consistent with normal operation per the Champion Check-a-Plug AV-27 card. The McCauley fixed pitch propeller exhibited slight leading edge polishing and chordwise scratches on one blade, the other blade tip was bent forward 90 degrees, and had substantial blade polishing along the leading edge and face of the blade tip. No preaccident mechanical failures or malfunctions were found that would have precluded normal operation of the airplane. ## Aircraft - Registration: [N2870S](https://openairdocs.org/deregistered/N2870S-2013-08-29), registration cancelled 2013-08-29, S/N 15066770, built 1967 (OpenAirDocs) - Reported make and model: CESSNA 150G - Registry model: [Cessna 150G](https://openairdocs.org/model/cessna-150g) (registry code 2071816) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 15066770 - Airframe hours: 5803 - Engines: CONT MOTOR O-200 SERIES 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Utility - Last inspection: Annual, November 17, 2010, 17 hours before - Departed: KWN8, Chattaroy, WA - Destination: 66S, Cavanaugh Bay, ID - Airport: K66S, Cavanaugh Bay Airport, runway 15, 3,100 × 120 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 85; injuries: serious; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review July 1, 2011; seat: left; flight hours: 900 total, 40 in this make and model, 12 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 7 knots, gusting 15 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 73 °F, dew point 50 °F - Altimeter: 30.02 inHg - Observed at: KSZT, 18 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 20110823017899A](https://openairdocs.org/incident/20110823017899A), Aug 23, 2011: Cessna 150G, Cavanaugh Bay, ID, Substantial damage. Witnesses observed the aircraft approach the Cavanaugh Bay airstrip. A witness indicated that he believed the aircraft was slow on final approach. Near the… ## Other investigations on N2870S (2) 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. - [NTSB CHI02CA287](https://openairdocs.org/ntsb/CHI02CA287), Sep 18, 2002: Cessna 150G (N2870S), Dodge Center, MN, substantial damage. Probable cause: The pilot's misjudgment of distance resulting in an undershoot of the runway. - [NTSB MKC70DDQ01](https://openairdocs.org/ntsb/MKC70DDQ01), Jan 13, 1970: Cessna 150 (N2870S), Miller, SD, substantial damage ## Docket (8 files) The files NTSB released with the investigation on October 24, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81583. 13.5 MB in all. - Witness Statements (item 1, .PDF, 54 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377576&FileExtension=.PDF&FileName=Witness%20Statements-Redacted.PDF - Photo 1 - Grass Runway (item 2, .PDF, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40379905&FileExtension=.PDF&FileName=Photo%201%20-%20Grass%20Runway-Master.PDF - Photo 2 - Airplane Wreckage 1 (item 3, .PDF, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377578&FileExtension=.PDF&FileName=Photo%202%20-%20Airplane%20Wreckage%201-Master.PDF - Photo 3 - Airplane Wreckage 2 (item 4, .PDF, 3.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377579&FileExtension=.PDF&FileName=Photo%203%20-%20Airplane%20Wreckage%202-Master.PDF - Photo 4 - Airplane Wreckage 3 (item 5, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377581&FileExtension=.PDF&FileName=Photo%204%20-%20Airplane%20Wreckage%203-Master.PDF - Record of Conversation with the Pilot (item 6, .PDF, 93 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377582&FileExtension=.PDF&FileName=Record%20of%20Conversation%20with%20the%20Pilot-Redacted.PDF - Wreckage Examination Report (item 7, .PDF, 138 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377583&FileExtension=.PDF&FileName=Wreckage%20Examination%20Report-Master.PDF - Airplane Maintenance Records (extract) (item 8, .PDF, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40379335&FileExtension=.PDF&FileName=Airplane%20Maintenance%20Records%20(extract)-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.