# NTSB WPR15LA099: Beech A36TC, N3685W, Flagstaff, AZ, January 18, 2015 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 18, 2015, 12:35 local (19:35 UTC) - Place: Flagstaff, AZ - Coordinates: 35.140277, -111.669166 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.1403&lon=-111.6692&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report August 11, 2015 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration FSDO - NTSB case key (mKey): 90700 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR15LA099 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/90700/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=90700 - Page: https://openairdocs.org/ntsb/WPR15LA099 ## Probable cause The pilot's improper landing flare and loss of airplane control, which resulted in a hard landing and the subsequent failure of the nose landing gear. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: landing flare](https://openairdocs.org/ntsb-findings/01062041): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Beech A36TC, 1 case](https://openairdocs.org/ntsb-findings/01062041/cases.md?model=1151603), [All aircraft, 1,285 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Beech A36TC, 9 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1151603), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Beech A36TC, 2 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=1151603), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Beech A36TC, 8 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1151603), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Beech A36TC, 2 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=1151603), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The pilot stated that, during landing, the airplane bounced and that he subsequently applied back pressure to the elevator in an effort to deplete the excess energy. The airplane touched down a second time, and the pilot held the airplane in a nose-high attitude. The airspeed decreased, and the airplane eventually came to rest on its nose. Two air traffic controllers witnessed the accident from the airport traffic control tower. They both reported that the airplane bounced a number of times during the landing sequence. One of the controllers reported that the initial landing was hard and on the nosewheel first, which caused the airplane to porpoise down the runway before the nose landing gear (NLG) collapsed. Examination of the of the upper NLG torque knee revealed that it exhibited grinding damage and that its mounting lug, which had broken free, was elongated and that its fracture surfaces exhibited features consistent with overload. Additionally, the nosewheel fork assembly had bent aft, and the forward landing gear brace had broken into three pieces. All of the observed damage was consistent with overload failures. Further, due to the design of the landing gear system, the type of damage observed on the NLG could only have resulted from excessive forward loads being placed on it. Although the pilot reported that he thought the NLG failed due to a preexisting mechanical failure of the upper torque link, the evidence clearly indicates that it was connected to the lower torque knee before the landing and that it failed in overload during the initial hard landing and subsequent separation from the airplane. ## Factual narrative On January 18, 2015, about 1235 mountain standard time, a Beech A36TC, N3685W, experienced a nose gear collapse during landing at Flagstaff Pulliam Airport, Flagstaff, Arizona. The airplane was registered to, and operated by, the pilot under the provisions of 14 Code of Federal Regulations Part 91. The commercial pilot and passenger were not injured, and the airplane sustained substantial damage. The cross-country personal flight departed Brackett Field Airport, La Verne, California, at 0934 Pacific standard time. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot reported that the airplane was travelling at 90 knots as they passed over the runway threshold, and that they touched down just past the displaced threshold. The airplane then bounced, and in response, he applied back pressure to the elevator control in an effort to deplete the excess energy. They touched down a second time on the main landing gear, and he held the airplane in a nose high attitude. The pilot surmised that at this point the nose landing gear scissor link (upper torque knee) failed, causing the nose wheel to over extend and release from the airplane. As the airspeed decreased, the airplane came to rest on its nose. Two air traffic controllers witnessed the accident from the airport's control tower. The tower controller stated that he observed the airplane bounce two or three times after landing and then the nose landing gear collapsed. The ground controller reported that he observed the airplane land hard on the nose wheel first, then porpoise up and down two more times, each time landing on the nose wheel first, before it collapsed. The airplane sustained substantial damage to the lower fuselage during the accident sequence, and the lower landing gear assembly, which was composed of the nosewheel, fork, and lower torque knee had become detached. The airplane was equipped with retractable landing gear, driven by an electrical actuator connected to a series of link rods. The nose landing gear extended forwards, and was held in the locked and down position by a wishbone-shaped aft brace and a single forward brace. In the extended mode, both braces were held in position by a series of control arms connected to the landing gear link rods. Sections of the lower nose gear assembly were recovered from the airplane and examined by the NTSB investigator-in-charge. Examination revealed that the nose wheel fork and piston assembly had separated from the barrel. The nose wheel fork casting had bent about 3 degrees aft relative to the piston. The lower torque knee remained attached to the fork by its pin. Its connecting bolt for the upper torque knee was bent about 10 degrees, and remained in place with its bushings, washers and nut. The upper torque knee remained attached to the barrel assembly. The upper knee's attachment lugs had been ground down to their bearing surfaces, with the score marks in a longitudinal direction consistent with runwaysurface contact. The lug connecting the lower knee was twisted about 5 degrees, and the forward section of the lug was not located. The lug exhibited similar grinding damage, and the radius of its attachment hole was elongated. The forward landing gear brace had separated into three sections. Reassembly of the fragments revealed that the brace had bent 30 degrees midspan in a downwards direction prior to failure. The forward section remained attached to the barrel and brace assembly of the landing gear; the lug at the aft end of the brace had broken away. The nosewheel tire remained attached to its axle. The tire exhibited a half inch deep gouge to a six inch portion of its center tread. The separation surfaces of all the components exhibited varying combinations of rough grainy texture, jagged edges, ductile dimpling, and 45-degree sheer lip features. No ratchet marks, striations, or "beachmarks" were observed. ## Aircraft - Registration: [N3685W](https://openairdocs.org/aircraft/N3685W), registered now, S/N EA-113, built 1980 (OpenAirDocs) - Reported make and model: BEECH A36TC - Registry model: [Beech A36TC](https://openairdocs.org/model/beech-a36tc) (registry code 1151603) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: EA-113 - Year built: 1980 - Airframe hours: 3034 - Engines: Continental TSIO 520 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Utility - Last inspection: Annual, December 16, 2014, 3 hours before - Departed: POC, LA VERNE, CA - Destination: FLG, Flagstaff, AZ - Airport: FLG, Flagstaff Pulliam, runway 21, 8,800 × 150 ft, asphalt - Equipment: Stall warning system, Onboard weather, Handheld GPS, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review May 10, 2014; seat: right; restraint: 3-point; flight hours: 2,770 total, 1,604 in this make and model, 2,441 as pilot in command, 23 in the last 90 days, 18 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point 27 °F - Altimeter: 30.37 inHg - Observed at: KFLG ## 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 20150118001299A](https://openairdocs.org/incident/20150118001299A), Jan 18, 2015: Beech A36TC, Flagstaff, AZ, Substantial damage. 1-18-15, Aircraft landed on RNWY21 at kflg and on landing roll out the nose gear collasped. The nose wheel and strut departed the nose gear assy and was drug… ## Docket (19 files) The files NTSB released with the investigation on June 15, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=90700. 29.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427895&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Tower Controller Statements (item 2, .PDF, 191 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427896&FileExtension=.PDF&FileName=Tower%20Controller%20Statements-Redacted.PDF - Exemplar Nose Landing Gear Assembly (item 3, .PDF, 1 photo, 187 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427897&FileExtension=.PDF&FileName=Exemplar%20Nose%20Landing%20Gear%20Assembly-Master.PDF - Bonanza Series Maintenance Manual Excerpts (item 4, .PDF, 190 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427898&FileExtension=.PDF&FileName=Bonanza%20Series%20Maintenance%20Manual%20Excerpts-Master.PDF - Photo 1 - Damage to Airplane (item 5, .PDF, 629 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427899&FileExtension=.PDF&FileName=Photo%201%20-%20Damage%20to%20Airplane-Master.PDF - Photo 2 - Damage to Upper Torque Knee (item 6, .PDF, 595 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427900&FileExtension=.PDF&FileName=Photo%202%20-%20Damage%20to%20Upper%20Torque%20Knee-Master.PDF - Photo 3 - Damage to Tire (item 7, .PDF, 333 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427901&FileExtension=.PDF&FileName=Photo%203%20-%20Damage%20to%20Tire-Master.PDF - Photo 4 - Lower Nose landing Gear Assembly (item 8, .PDF, 408 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427902&FileExtension=.PDF&FileName=Photo%204%20-%20Lower%20Nose%20landing%20Gear%20Assembly-Master.PDF - Photo 5 - Bent Nose Landing Gear Fork (item 9, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427903&FileExtension=.PDF&FileName=Photo%205%20-%20Bent%20Nose%20Landing%20Gear%20Fork-Master.PDF - Photo 6 - Lower Torque Knee Attach Bolt (item 10, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427904&FileExtension=.PDF&FileName=Photo%206%20-%20Lower%20Torque%20Knee%20Attach%20Bolt-Master.PDF - Photo 7 - Upper Torque Knee (item 11, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427905&FileExtension=.PDF&FileName=Photo%207%20-%20Upper%20Torque%20Knee-Master.PDF - Photo 8 - Upper Torque Knee Fracture Surface (item 12, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427906&FileExtension=.PDF&FileName=Photo%208%20-%20Upper%20Torque%20Knee%20Fracture%20Surface-Master.PDF - Photo 9 - Upper Torque Knee Attachment Hole (item 13, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427907&FileExtension=.PDF&FileName=Photo%209%20-%20Upper%20Torque%20Knee%20Attachment%20Hole-Master.PDF - Photo 10 - Nose Landing Gear Forward Brace (item 14, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427908&FileExtension=.PDF&FileName=Photo%2010%20-%20Nose%20Landing%20Gear%20Forward%20Brace-Master.PDF - Photo 11 - Nose Landing Gear Forward Brace Lug (item 15, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427909&FileExtension=.PDF&FileName=Photo%2011%20-%20Nose%20Landing%20Gear%20Forward%20Brace%20Lug-Master.PDF - Photo 12 - Nose Landing Gear Forward Brace Lug Fracture Surfaces (item 16, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427910&FileExtension=.PDF&FileName=Photo%2012%20-%20Nose%20Landing%20Gear%20Forward%20Brace%20Lug%20Fracture%20Surfaces-Master.PDF - Photo 13 - Nose Landing Gear Forward Brace Lug Fracture Surfaces (item 17, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427911&FileExtension=.PDF&FileName=Photo%2013%20-%20Nose%20Landing%20Gear%20Forward%20Brace%20Lug%20Fracture%20Surfaces-Master.PDF - Photo 14 - Nose Landing Gear Forward Brace Midspan Fracture (item 18, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427912&FileExtension=.PDF&FileName=Photo%2014%20-%20Nose%20Landing%20Gear%20Forward%20Brace%20Midspan%20Fracture-Master.PDF - Photo 15 - Nose Landing Gear Forward Brace Midspan Fracture (item 19, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40427913&FileExtension=.PDF&FileName=Photo%2015%20-%20Nose%20Landing%20Gear%20Forward%20Brace%20Midspan%20Fracture-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.