# NTSB WPR11FA390: Piper PA-18-150, N7666D, Forsyth, MT, August 18, 2011 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: August 18, 2011, 09:25 local (15:25 UTC) - Place: Forsyth, MT - Coordinates: 46.578334, -106.9225 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.5783&lon=-106.9225&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed, report July 30, 2014 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 81536 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11FA390 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81536/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81536 - Page: https://openairdocs.org/ntsb/WPR11FA390 ## Probable cause The pilot’s failure to maintain adequate airspeed while maneuvering, which resulted in a stall/mush, loss of control, and impact with terrain. ## 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: [Piper PA-18-150, 24 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=7101828), [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: [Piper PA-18-150, 10 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=7101828), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-18-150, 160 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7101828), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Terrain](https://openairdocs.org/ntsb-findings/03021000): Environmental issues › Physical environment · Not specified; cases with it: [Piper PA-18-150, 3 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md?model=7101828), [All aircraft, 267 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Piper PA-18-150, 41 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=7101828), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Maneuvering: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper PA-18-150, 115 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7101828), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The operator reported that the pilot and passenger were going to survey a prairie dog town and take pictures. Hunters in the accident area observed the airplane fly overhead and descend below mountainous terrain while in a turn. The airplane crashed in an open field. The airplane damage and the ground scars at the accident site were consistent with the airplane being in a stalled condition at the time of the accident. The pilot likely failed to maintain adequate airspeed as he was increasing the bank angle to maintain visual reference to the ground, which resulted in a stall/mush, loss of control, and collision with terrain. A postaccident examination of the airframe and engine revealed no evidence of a mechanical failure or malfunction that would have precluded normal operation. ## Factual narrative There were no maintenance records available for review; the family believed the airplane maintenance records were onboard the airplane at the time of the accident. According to FAA records, the accident pilot purchased the airplane on November 15, 2006. According to FAA form 337, Major Repair and Alteration (Airframe, Powerplant, Propeller, or Appliance), on February 23, 2010, a Lycoming O-320-B2C, serial number 49324-27AC, engine was installed on the airplane, per Supplemental Type Certificate (STC) SA00522SE. The form also indicated that a continued airworthiness had been accomplished per 100-hour guidelines in Federal Aviation Regulation (FAR) Part 43.2-43.15. On August 18, 2011, about 0925 mountain daylight time, a Piper PA-18-150, N7666D, impacted an open area in mountainous terrain near Forsyth, Montana. Big Sky Wildlife Consultants operated the airplane under the provisions of 14 Code of Federal Regulations Part 91 as a contract flight to count prairie dogs. The commercial pilot and one passenger were fatally injured; the airplane was substantially damaged as a result of impact forces and post impact fire. According to friends of the pilot, the two men were going up to take pictures of a prairie dog town and conduct a survey of the population. According to witnesses hunting in the area, they observed the accident airplane fly overhead, descend in a turn below the mountain tops, and then observed smoke. A postmortem examination was conducted by the Forensic Medicine and Pathology, PLLC, Billings, Montana, on August 19, 2011. The cause of death was reported as smoke inhalation, secondary to fire following an airplane crash. The FAA's Civil Aerospace Medical Institute performed forensic toxicology on specimens from the pilot, with no carbon monoxide, cyanide, or volatiles, or tested drugs detected. The pilot, age 39, held a commercial pilot certificate with ratings for airplane single-engine land and instrument airplane issued March 1, 2011. The pilot held a second-class medical issued on March 11, 2011, with no limitations. No personal flight records were located for the pilot, and the company and family believed that the pilot's logbook was onboard the airplane at the time of the accident. The National Transportation Safety Board (NTSB) investigator-in-charge (IIC) obtained the aeronautical experience listed in this report from a review of the Federal Aviation Administration (FAA) airmen medical records on file in the Airman and Medical Records Center located in Oklahoma City, Oklahoma. The pilot reported on his most recent medical application dated March 11, 2011, a total time of 3,000 hours with 500 hours logged in the last 6 months. Examination of the accident site revealed that the airplane came to rest upright in an open field on an approximate magnetic heading of 290 degrees. All major structural components of the airplane were located within 30 feet of the main wreckage. A ground scar, located directly under the right wing, 20inches in length, was observed. An outboard portion of a propeller blade was located next to the ground scar. Examination of the airplane revealed that a majority of the airframe fabric had been consumed by fire. The instrument panel was consumed by fire. The throttle handle was bent, and observed in the full forward position. Engine continuity was established from the throttle handle to the engine. The flap handle appeared to be in the "down" position, consistent with the flaps being retracted. Flight control continuity was established throughout the airplane from the cockpit controls to all primary flight control surfaces. A report is attached to the public docket for this accident The visual examination of the engine revealed that it remained partially attached to the airframe and exhibited fire and thermal damage. All four cylinders remained attached to the engine crankcase. The propeller remained attached to the engine crankshaft propeller flange. Both propeller blades exhibited S-bending with chord wise scratching. A detailed report is attached to the public docket for this accident. ## Aircraft - Registration: [N7666D](https://openairdocs.org/deregistered/N7666D-2015-05-21), registration cancelled 2015-05-21, S/N 18-5935, built 1957 (OpenAirDocs) - Reported make and model: PIPER PA-18-150 - Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-5935 - Engines: LYCOMING O-320 SERIES 180 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Aerial observation, Part 91 - Operator: Cyrus Chad H DBA - Registered owner: Cyrus Chad H DBA - Airworthiness certificate: Standard, Normal - Departed: MLS, MILES CITY, MT - Destination: MLS, MILES CITY, MT - Airport: MLS, Frank Wiley Field ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; injuries: fatal; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; seat: front; toxicology performed; flight hours: 3,000 total, 500 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 45 °F - Altimeter: 29.90 inHg - Observed at: MLS, 32 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 20110818018869A](https://openairdocs.org/incident/20110818018869A), Aug 18, 2011: Piper PA-18-150, Forsyth, MT, Destroyed, 2 fatal. On August 18, 2011 at 0900 MST, a Piper PA-18-150 collided with the ground while performing aerial observations of wildlife on the ground. Visual… ## Other investigations on N7666D (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 ANC76FAH03](https://openairdocs.org/ntsb/ANC76FAH03), Mar 28, 1976: Piper PA-18 (N7666D), Anchorage, AK, substantial damage - [NTSB ANC74DAH15](https://openairdocs.org/ntsb/ANC74DAH15), Jun 10, 1974: Piper PA-18 (N7666D), Slana, AK, substantial damage ## Docket (13 files) The files NTSB released with the investigation on July 25, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81536. 28.3 MB in all. - Photo – Front View (NTSB) (item 1, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414415&FileExtension=.PDF&FileName=Photo%20%E2%80%93%20Front%20View%20(NTSB)%0D%0A-Master.PDF - Photo – Left View (NTSB) (item 2, .PDF, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414416&FileExtension=.PDF&FileName=Photo%20%E2%80%93%20Left%20View%20(NTSB)-Master.PDF - Photo – Rear View (NTSB) (item 3, .PDF, 3.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414417&FileExtension=.PDF&FileName=Photo%20%E2%80%93%20Rear%20View%20(NTSB)-Master.PDF - Photo – Right View (NTSB) (item 4, .PDF, 3.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414418&FileExtension=.PDF&FileName=Photo%20%E2%80%93%20Right%20View%20(NTSB)-Master.PDF - Photo –View of Engine (NTSB) (item 5, .PDF, 4.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414419&FileExtension=.PDF&FileName=Photo%20%E2%80%93View%20of%20Engine%20(NTSB)-Master.PDF - Photo – Left Propeller Blade (NTSB) (item 6, .PDF, 3.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414420&FileExtension=.PDF&FileName=Photo%20%E2%80%93%20Left%20Propeller%20Blade%20(NTSB)%20-Master.PDF - Photo – Right Propeller Blade (NTSB) (item 7, .PDF, 3.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414421&FileExtension=.PDF&FileName=Photo%20%E2%80%93%20Right%20Propeller%20Blade%20(NTSB)%20%0D%0A-Master.PDF - Photo – Right Propeller Blade Tip (NTSB) (item 8, .PDF, 4.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414422&FileExtension=.PDF&FileName=Photo%20%E2%80%93%20Right%20Propeller%20Blade%20Tip%20(NTSB)-Master.PDF - NTSB Accident Site Examination Report (item 9, .PDF, 157 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414423&FileExtension=.PDF&FileName=NTSB%20Accident%20Site%20Examination%20Report-Master.PDF - Rosebud County Sheriff’s Report (item 10, .PDF, 160 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414425&FileExtension=.PDF&FileName=Rosebud%20County%20Sheriff%E2%80%99s%20Report-Redacted.PDF - Aircraft Records (item 11, .PDF, 716 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414426&FileExtension=.PDF&FileName=Aircraft%20Records-Redacted.PDF - Toxicological Report – Pilot (item 12, .PDF, 113 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414427&FileExtension=.PDF&FileName=Toxicological%20Report%20%E2%80%93%20Pilot-Master.PDF - Toxicological Report –Passenger (item 13, .PDF, 113 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414428&FileExtension=.PDF&FileName=Toxicological%20Report%20%E2%80%93Passenger-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.