# NTSB CEN11FA444: Boeing B75N1, N4473N, Wetmore, CO, July 3, 2011 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: July 3, 2011, 15:50 local (21:50 UTC) - Place: Wetmore, CO - Coordinates: 38.194999, -105.086387 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.1950&lon=-105.0864&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) - Highest injury: Fatal - Injuries: 1 fatal, 1 serious - Status: Completed, report September 13, 2012 - Report: Approved by Office Director - NTSB office: Central Region - NTSB case key (mKey): 80968 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11FA444 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/80968/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=80968 - Page: https://openairdocs.org/ntsb/CEN11FA444 ## Probable cause The pilot's failure to maintain clearance from terrain while maneuvering at low altitude. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Boeing B75N1, 2 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=1380144), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) - [Attention/monitoring: task monitoring/vigilance](https://openairdocs.org/ntsb-findings/02021520): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Boeing B75N1, 1 case](https://openairdocs.org/ntsb-findings/02021520/cases.md?model=1380144), [All aircraft, 330 cases](https://openairdocs.org/ntsb-findings/02021520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) (defining event); cases with it: [Boeing B75N1, 2 cases](https://openairdocs.org/ntsb-events/220/sequence.md?model=1380144), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md) - [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Boeing B75N1, 10 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1380144), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Post-impact: Fire/smoke (post-impact)](https://openairdocs.org/ntsb-events/170); cases with it: [Boeing B75N1, 1 case](https://openairdocs.org/ntsb-events/170/sequence.md?model=1380144), [All aircraft, 354 cases](https://openairdocs.org/ntsb-events/170/sequence.md) ## Analysis According to the passenger, the pilot was maneuvering the airplane at low altitude in mountainous terrain. The passenger reported that the pilot was flying the airplane “low and slow,” the airplane’s bank angle began to increase, and the airplane descended and collided with trees. A postimpact fire consumed a majority of the wreckage. An examination did not find any anomalies with the airframe or engine that would have precluded normal operation. ## Factual narrative HISTORY OF FLIGHT On July 3, 2011, approximately 1550 mountain daylight time, a Boeing B75N1, impacted terrain near Wetmore, Colorado. The commercial pilot was fatally injured and the pilot-rated passenger sustained minor injuries. The airplane was substantially damaged and a postimpact fire ensued. The airplane was registered to and operated by Quetzal Limited Partnership, Oklahoma City, Oklahoma, under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The local flight originated from the Fremont County Airport (1V6), Canon City, Colorado about 1515. The pilot-rated passenger reported that after departing 1V6, the airplane was flown at low altitude around several locations before circling the passenger’s home. While flying west from the passenger’s home there was no communication between him and the pilot. The passenger said that the airplane got low and slow, and the airplane’s bank increased. He further reported that the airplane descended and collided with trees. The passenger found the pilot unresponsive and attempted to get the pilot out of the airplane. A fire began and the passenger retreated from the spreading fire. The passenger remarked that there were no changes in engine noise. PERSONNEL INFORMATION The pilot, age 50, held a commercial pilot certificate for airplane single engine land, single engine sea, and instrument airplane. He held a private pilot certificate for airplane multi-engine land. A third class medical certificate, without restrictions, was issued on October 14, 2009, at which time the pilot reported having accumulated 1,500 hours of total time, with 90 hours in the previous six months. The pilot’s logbook was not obtained during the investigation and it is unknown how many hours in make and model the pilot had logged. The pilot had acquired the accident airplane on October 13, 2009. AIRCRAFT INFORMATION The tandem two-seat, tube and fabric, bi-wing airplane, serial number 75-1183, was manufactured in 1947. A 450 horsepower Pratt & Whitney R-985 engine drove a Hamilton Standard 2B20 constant speed propeller. The airplane was issued a standard aerobatic airworthiness certificate on August 19, 1992. The airplane was configured with dual pilot controls. METEOROLOGICAL INFORMATION At 1331, an automated weather reporting facility at Pueblo, Colorado, located 28 nautical miles to the east of the accident, reported wind from 080 degrees at 23 knots gusting to 28 knots, visibility 10 miles, a clear sky, temperature 97 degrees Fahrenheit (F), dew point 26 F, and a barometric pressure of 30.01 inches of Mercury. WRECKAGE AND IMPACT INFORMATION The first impact signatures were damaged trees located 40 to 60 feet east southeast of the accident site. Several downed branches displayed clean angular cuts. The wreckage was located on the northern face of a ravine. The airplane came to rest in an uprightposition on a 240 degrees magnetic heading. The main wreckage consisted of the propeller, engine, and fuselage frame. Both bi-wings were almost completely consumed. Flight control continuity was confirmed to the rudder and elevators surfaces, and cable continuity was established to the aileron attachments. The cockpit instruments were unreadable due to thermal damage. The pilot’s restraint belt buckle was found in the secured position. One blade of the two-bladed metal propeller was partially buried in the ground. The other blade displayed gouges, chord wise scratches, and was bent forward near mid-span. The throttle quadrant was thermally damaged with the throttle, mixture, and propeller pitch lever set about 1/3 open. The engine was impact and thermally damaged. There were no anomalies detected with the airframe or engine which would have precluded normal operation. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot on July 6, 2011, by the El Paso County Coroner as authorized by the Custer County Coroner. The manner of death was ruled an accident. The medical examiner noted the presence of smoke inhalation and a postmortem carboxyhemoglobin of 7 percent. The autopsy found no anatomic reason for the pilot’s incapacitation. The FAA Civil Aerospace Medical Institute (CAMI), Oklahoma City, Oklahoma, performed forensic toxicology on specimens from the pilot. The toxicology report marked putrefaction “yes.” The specimens received were deemed unsuitable for carbon monoxide analysis. Tests for cyanide, ethanol, and drugs were negative. ## Aircraft - Registration: [N4473N](https://openairdocs.org/deregistered/N4473N-2018-01-23), registration cancelled 2018-01-23, S/N 75-1183, built 1941 (OpenAirDocs) - Reported make and model: BOEING B75N1 - Registry model: [Boeing B75N1](https://openairdocs.org/model/boeing-b75n1) (registry code 1380144) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 75-1183 - Engines: P&W R-985 SERIES 450 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Personal, Part 91 - Operator: Quetzal Limited Partnership - Registered owner: Quetzal Limited Partnership - Airworthiness certificate: Standard, Aerobatic - Departed: 1V6, Canon City, CO - Destination: 1V6, Canon City, CO ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: fatal; commercial, private; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; seat: rear; toxicology performed; flight hours: 1,500 total ## Weather - Conditions: Visual (VMC), Day - Wind: 80° at 16 knots, gusting 25 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 97 °F, dew point 37 °F - Altimeter: 30.01 inHg - Observed at: PUB, 28 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 20110703011679A](https://openairdocs.org/incident/20110703011679A), Jul 3, 2011: Boeing B75N1, Greenwood, CO, Destroyed, 1 fatal. At 1545 on 07/03/2011, aircraft N4473N, a Boeing B75N1 stearman, impacted ground in mountainous terrain near Greenwood, CO. Aircraft was destroyed. Pilot… ## Docket (6 files) The files NTSB released with the investigation on July 12, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=80968. 3.6 MB in all. - Passenger Statement (item 1, .PDF, 40 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40351508&FileExtension=.PDF&FileName=Passenger%20Statement-Redacted.PDF - Photo 1. Wreckage overview (item 2, .PDF, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369182&FileExtension=.PDF&FileName=Photo%201.%20Wreckage%20overview-Master.PDF - Photo 2. Engine (item 3, .PDF, 202 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368973&FileExtension=.PDF&FileName=Photo%202.%20Engine-Master.PDF - Photo 3. Throttle quadrant (item 4, .PDF, 324 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368977&FileExtension=.PDF&FileName=Photo%203.%20Throttle%20quadrant-Master.PDF - Toxicological Report (item 5, .PDF, 319 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369186&FileExtension=.PDF&FileName=Toxicological%20Report-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 6, .PDF, 79 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369264&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-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.