# NTSB DEN01FA161: Piper PA-31-350, N161RB, Pagosa Springs, CO, September 24, 2001 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: September 24, 2001, 09:04 local (15:04 UTC) - Place: Pagosa Springs, CO - Coordinates: 37.49472, -107.35028 - Nearby events: https://openairdocs.org/map.md?lat=37.4947&lon=-107.3503&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed, report July 25, 2002 - Report: Approved by Office Director - Parties: The New Piper Aircraft, Inc., Textron Lycoming - NTSB case key (mKey): 53505 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN01FA161 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/53505/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=53505 - Page: https://openairdocs.org/ntsb/DEN01FA161 ## Probable cause the flight crews' intentional low altitude flight, and failure to maintain obstacle clearance. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, maneuvering - low altitude flight/maneuver - intentional, flightcrew (cause) - clearance - not maintained, flightcrew (cause) - object - tree(s) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - mountainous/hilly ## Analysis The airplane was on a non-scheduled cargo flight which was projected to fly an approximate 240 degree course for 92 nm. The accident site was located on a heavily forested steep mountain side, 15 to 16 nm north of the airplane's projected course. The debris field began at an east-west ridge line, and progressed for 300 feet on a 010 degree track to the downed airplane. Examination of the airframe and engines revealed no evidence of preimpact discrepancies. The accident site was in an area where the Fall color of the aspens was at its peak. Additionally, it was an area where elk were sometimes observed. ## Factual narrative HISTORY OF FLIGHT On September 24, 2001, at 0904 mountain daylight time, a PA-31-350, N161RB, was destroyed following impact with terrain while maneuvering near Pagosa Springs, Colorado. The two commercial pilots received fatal injuries. Key Lime Air of Denver, Colorado, was operating the on demand domestic cargo flight under 14 CFR Part 135. Visual meteorological conditions prevailed for the cross-country flight that originated from Alamosa, Colorado, 24 minutes before the accident. A visual flight rules flight plan (VFR) had been filed, with Durango, Colorado, as its destination, but it was never activated. The operator said that the airplane was scheduled to depart Centennial Airport in Denver, Colorado (on its first flight of the day) at 0715. Denver Flight Service Station (FSS) reported that the pilot-in-command (PIC) had filed two VFR flight planes; one from Centennial Airport for 0715; and later, a second from Alamosa, Colorado, at 0815. Neither of them were opened. Fixed base operator (FBO) personnel at Alamosa, Colorado, reported the airplane departed for Durango, Colorado, at approximately 0840. The operator reported the aircraft was overdue at its destination, and an alert notice (ALNOT) was issued by the Denver FSS. The United States Forest Service (USFS) dispatch received a report of smoke and a potential forest fire at 0904. Upon investigation, USFS personnel discovered the airplane's wreckage. PERSONNEL INFORMATION The PIC started working for the operator on February 21, 2001. His college degree was in Aviation Maintenance Management. He was an instrument rated commercial pilot, and had earned his airframe and power plant mechanic certificates. At the time of the accident, he had accumulated approximately 1,962 hours of flight experience of which approximately 614 hours were in this make and model airplane. He held a first class medical certificate dated January 10, 2001; he was required to wear corrective lenses while performing the duties of a pilot. He successfully completed a FAR Part 135 Airman Proficiency Check on February 28, 2001. The second-in-command (SIC) pilot started working for the operator on November 21, 2000. He was an instrument rated commercial pilot with approximately 468 hours of flight experience at the time of the accident; he had 207 hours of flight time in this make and model airplane. He held a first class medical certificate dated November 6, 2000, which he had no limitations. He successfully completed a FAR Part 135 Airman Proficiency Check on December 3, 2000. The operator said that their records indicated that the two pilots had flown together on 17 different days for 91 flight legs. AIRCRAFT INFORMATION The airplane was a twin engine, propeller-driven, retractable gear, cargo configured airplane, which was manufactured by the Piper Aircraft Company in 1979. It was certificated for a maximum gross takeoff weight of 7,000 pounds (approximate empty weight of 4,000 pounds). The airplane was powered by two 350 horsepower Textron Lycoming fuel injected, turbocharged, reciprocating engines (TIO-540-J2BD and LTIO-540-J2BD). Aircraft maintenance records indicated that the last 100 hour inspection was accomplished on August 27, 2001. The airframe had accumulated approximately 9,022 hours of flight time, at the time of the accident. Cargo manifest records indicated that the airplane was loaded with approximately 461 pounds of cargo at the time of the accident. METEOROLOGICAL INFORMATION At 0853, the weather conditions at the Animas Air Park (elevation 6,684 feet), Durango, Colorado, 215 degrees 28 nautical miles (nm) from the accident site, were as follows: wind calm; visibility 10 statute miles; cloud condition clear; temperature 57 degrees Fahrenheit; dew point 37 degrees Fahrenheit; altimeter setting 30.45 inches. At 0852, the weather conditions at the San Luis Valley Regional/Bergman Field (elevation 7,539 feet), Alamosa, Colorado, 135 degrees 25 nm from the accident site, were as follows: wind calm; visibility 10 statute miles; cloud condition clear; temperature 46 degrees Fahrenheit; dew point 34 degrees Fahrenheit; altimeter setting 30.51 inches. WRECKAGE AND IMPACT INFORMATION The airplane was found on the east face of Graham Peak (N37 degrees, 29.68'; W107 degrees, 21.01'; elevation 10,404 feet) in the Rio Grande National Forest, approximately 25 miles northwest of Pagosa Springs, Colorado. The terrain at the accident site was steeply rising to the west and gently rising to the north. The impact area was forested with 50 to 70 foot high conifers which had 12 to 18 inch diameters. An approximate 300 foot longitudinal path of downed vegetation (large trees and many slashed 4 to 5 inch in diameter branches) and airplane debris, oriented 010 degrees, led to the downed aircraft. The initial topped trees were on an east-west oriented ridge line which was rising to the west. The Federal Aviation Administration (FAA) inspector, who went to the accident scene, reported that the outboard portions of the airplane's wings (from the inboard end of the ailerons to the wingtips) were found approximately 75 feet north of the beginning of the debris trail. He said that the unburned empennage, with the fuselage's entrance door, was found separated from the main cabin and cockpit area. The elevator trim drum forward extension measured 1 1/8 inches and displayed 8 threads; the airplane manufacturer's representative said this is consistent with a pitch trim setting of full nose up. The forward two-thirds of the fuselage and cockpit area, along with the inboard two-thirds of both wings (including both engines) were severely damaged by postimpact fire. The airplane manufacturer's representative, who looked at the wreckage in Greeley, Colorado, said that damage to the right outboard wing section indicated the airplane impacted the trees nose high in a right turn. All of the airplane's major components were accounted for at the accident site. The flight control surfaces were all identified. Flight control continuity was not established due to impact and thermal damage. The flaps and landing gear were determined to be in the up position. The cockpit area and instrument panel were destroyed by impact damage and postimpact fire. The engine control quadrant showed severe thermal damage; both throttles and propeller controls were found full forward. The mixture controls were loose and their position was undetermined; however, their thermal damage appeared consistent with the other levers when placed in the full rich position. The left propeller was separated from its engine. Rotation of the engine and its turbocharger were unsuccessful due to thermal damage. All engine accessories were intact, but were destroyed by fire. Borescoping of the engine, by the engine manufacturer's representative, found no discrepancies. The left propeller blades displayed chordwise and spanwise scratches, and the blade tips were bent aft and one tip was curled. The right engine received more thermal damage than the left engine. Attempts to rotate the engine and its turbocharger were unsuccessful; borescoping the engine and examining it through melted and burned areas identified no discrepancies. All engine accessories were intact, but were destroyed by fire. The right propeller assembly remained attached to the engine, and sustained extensive impact and thermal damage. All three blades exhibited leading edge impact nicks and light chordwise scratches. No preimpact engine or airframe anomalies, which might have affected the airplane's performance, were identified. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on both pilots by the Division of Forensic Pathology, Montrose Memorial Hospital, Montrose, Colorado, on September 27, 2001. The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed t ## Aircraft - Registration: [N161RB](https://openairdocs.org/deregistered/N161RB-2002-12-30), registration cancelled 2002-12-30, S/N 31-7952097, built 1979 (OpenAirDocs) - Reported make and model: Piper PA-31-350 - Registry model: [Piper PA-31-350](https://openairdocs.org/model/piper-pa-31-350) (registry code 7103110) (OpenAirDocs) - Registry engine: [Lycoming TI0-540 series](https://openairdocs.org/engine/lycoming-ti0-540-series) (registry code 41533, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 31-7952097 - Airframe hours: 9022 - Engines: Lycoming LTIO-540-J2BD 350 horsepower reciprocating; Lycoming TIO-540-J2BD 350 horsepower reciprocating - Damage: Destroyed - Fire: On-Ground - Flight: Part 135 - Operator: Key Lime Air - Registered owner: EDB Air, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 27, 2001, 32 hours before - Departed: KALS, ALAMOSA, CO - Destination: K00C, DURANGO, CO - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 24; injuries: fatal; commercial; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 1; last flight review February 28, 2001; seat: left; toxicology performed; flight hours: 1,962 total, 614 in this make and model, 1,871 as pilot in command, 251 in the last 90 days, 69 in the last 30 days, 2 in the last 24 hours - Co-pilot; age 26; injuries: fatal; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1; last flight review December 3, 2000; seat: right; toxicology performed; flight hours: 468 total, 208 in this make and model, 190 as pilot in command, 59 in the last 90 days, 27 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point 37 °F - Altimeter: 30.45 inHg - Observed at: KDRO, 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 20010924029609A](https://openairdocs.org/incident/20010924029609A), Sep 24, 2001: Piper PA31350, Pagosasprings, CO, No damage, 2 fatal. (-23) Aircraft crashed and burned approx. 5 miles south of graham peak (03 7.29'40.7"n 107.21'0.00) or 29 miles north of pagosa springs. Reason of crash is… ## Docket (20 files) The files NTSB released with the investigation on July 8, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=53505. 5.7 MB in all. - Supplement E (item 1, .PDF, 61 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161803&FileExtension=.PDF&FileName=Supplement%20E-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 316 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370602&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Witness Statement (item 3, .PDF, 26 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370603&FileExtension=.PDF&FileName=Witness%20Statement-Redacted.PDF - Maps or Charts of Accident Area, Wreckage Diagrams (item 4, .PDF, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161806&FileExtension=.PDF&FileName=Maps%20or%20Charts%20of%20Accident%20Area,%20Wreckage%20Diagrams-Master.PDF - Reports from Local Agencies (item 5, .PDF, 475 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370604&FileExtension=.PDF&FileName=Reports%20from%20Local%20Agencies-Redacted.PDF - Other Pertinent Forms and Reports (item 6, .PDF, 608 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370605&FileExtension=.PDF&FileName=Other%20Pertinent%20Forms%20and%20Reports-Redacted.PDF - Statement of Party Representatives to NTSB Investigation (item 7, .PDF, 64 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370606&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 8, .PDF, 42 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370607&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Redacted.PDF - Toxicological Reports (item 9, .PDF, 111 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370608&FileExtension=.PDF&FileName=Toxicological%20Reports-Redacted.PDF - Photo 1 - The reverse entry path of N161RB into the forest (looking south). (item 10, .PDF, 343 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161861&FileExtension=.PDF&FileName=Photo%201%20-%20The%20reverse%20entry%20path%20of%20N161RB%20into%20the%20forest%20(looking%20south).-Master.PDF - Photo 2 - Slashed timber from N161RB. (item 11, .PDF, 302 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161816&FileExtension=.PDF&FileName=Photo%202%20-%20Slashed%20timber%20from%20N161RB.-Master.PDF - Photo 3 - Slashed timber from N161RB. (item 12, .PDF, 254 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161817&FileExtension=.PDF&FileName=Photo%203%20-%20Slashed%20timber%20from%20N161RB.-Master.PDF - Photo 4 - A separated wing tip from N161RB. (item 13, .PDF, 181 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161820&FileExtension=.PDF&FileName=Photo%204%20-%20A%20separated%20wing%20tip%20from%20N161RB.-Master.PDF - Photo 5 - The impact site of N161RB. (item 14, .PDF, 293 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161822&FileExtension=.PDF&FileName=Photo%205%20-%20The%20impact%20site%20of%20N161RB.-Master.PDF - Photo 6 - The empennage of N161RB and other debris. (item 15, .PDF, 258 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161825&FileExtension=.PDF&FileName=Photo%206%20-%20The%20empennage%20of%20N161RB%20and%20other%20debris.-Master.PDF - Photo 7 - The accident site of N161RB. Note mountain slope in the background. (item 16, .PDF, 221 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161826&FileExtension=.PDF&FileName=Photo%207%20-%20The%20accident%20site%20of%20N161RB.%20%20Note%20mountain%20slope%20in%20the%20background.-Master.PDF - Photo 8 - The accident site N161RB. (item 17, .PDF, 229 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161827&FileExtension=.PDF&FileName=Photo%208%20-%20The%20accident%20site%20N161RB.-Master.PDF - Photo 9 - Another view of the accident site. (item 18, .PDF, 216 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161828&FileExtension=.PDF&FileName=Photo%209%20-%20Another%20view%20of%20the%20accident%20site.-Master.PDF - Photo 10 - The left engine of N161RB. (item 19, .PDF, 221 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161829&FileExtension=.PDF&FileName=Photo%2010%20-%20The%20left%20engine%20of%20N161RB.-Master.PDF - Photo 11 - The right engine of N161RB. (item 20, .PDF, 285 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40161830&FileExtension=.PDF&FileName=Photo%2011%20-%20The%20right%20engine%20of%20N161RB.-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.