# NTSB CEN16LA336: Beech E-55, N855T, Wichita Falls, TX, August 24, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 24, 2016, 18:30 local (23:30 UTC) - Place: Wichita Falls, TX - Coordinates: 33.988887, -98.491943 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.9889&lon=-98.4919&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Landing gear not configured](https://openairdocs.org/ntsb-events/095) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 5, 2018 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration; LBB FSDO - NTSB case key (mKey): 93902 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN16LA336 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93902/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93902 - Page: https://openairdocs.org/ntsb/CEN16LA336 ## Probable cause The failure of the landing gear assembly snap ring, which prevented the pilot from being able to extend the landing gear and resulted in a gear-up landing. Also causal was the lack of the assembly's overhaul in accordance with the airplane maintenance manual. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: gear extension and retract sys](https://openairdocs.org/ntsb-findings/01023230): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Beech E-55, 1 case](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=1152732), [All aircraft, 416 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md) - [Landing gear system: gear extension and retract sys](https://openairdocs.org/ntsb-findings/01023230): Aircraft › Aircraft systems · Not serviced/maintained (probable cause); cases with it: [Beech E-55, 1 case](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=1152732), [All aircraft, 416 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md) - [Maintenance: scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010): Personnel issues › Task performance · Other (probable cause); cases with it: [Beech E-55, 1 case](https://openairdocs.org/ntsb-findings/02062010/cases.md?model=1152732), [All aircraft, 320 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md) - [Maintenance/inspections: scheduled maint checks](https://openairdocs.org/ntsb-findings/01010520): Aircraft › Aircraft handling/service · Not serviced/maintained (probable cause); cases with it: [Beech E-55, 1 case](https://openairdocs.org/ntsb-findings/01010520/cases.md?model=1152732), [All aircraft, 76 cases](https://openairdocs.org/ntsb-findings/01010520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330); cases with it: [Beech E-55, 2 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=1152732), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Landing-flare/touchdown: Landing gear not configured](https://openairdocs.org/ntsb-events/095) (defining event); cases with it: [Beech E-55, 3 cases](https://openairdocs.org/ntsb-events/095/sequence.md?model=1152732), [All aircraft, 584 cases](https://openairdocs.org/ntsb-events/095/sequence.md) ## Analysis The flight instructor stated that, after the landing gear handle was placed in the gear-down position, he and the student pilot noticed electrical smoke and fumes but no fire. Although they restored electrical power, they were unable to fully extend the landing gear, which resulted in a gear-up landing. Postaccident examination of the main landing gear retraction actuator assembly revealed a broken snap ring within the manual crank extension housing, which allowed the actuator worm gear to reposition itself beyond the actuator worm sector travel limits. A review of the airplane's maintenance records found no record showing that the landing gear actuator assembly had been repaired/overhauled in accordance with the airplane maintenance manual. According to the maintenance manual, the actuator assembly is to be overhauled or replaced every 2,000 hours for gray- or green-colored assemblies. The assembly that was examined was green. The airplane had a total time of 6,184.5 hours. Given the condition of the landing gear actuator assembly, the operator should have been overhauled or replaced the actuator assembly in accordance with the manual. ## Factual narrative On August 24, 2016, about 1830 central daylight time, a Beech E-55, N855T, impacted the runway surface during a gear-up landing on runway 17 at Sheppard Air Force Base/Wichita Falls Municipal Airport (SPS), Wichita Falls, Texas. The airplane sustained substantial damage to the bottom fuselage structure. The flight instructor and a commercial rated dual student pilot were uninjured. The airplane was registered to and operated by Cobra Kai Inc (dba Cobra Kai Flight Academy) under 14 Code of Federal Regulations Part 141 as an instructional flight that was operating on an instrument flight rules flight plan. Visual meteorological conditions prevailed at the time of the accident. The flight originated from Kickapoo Downtown Airport, Wichita Falls, Texas at 1609 and diverted to SPS. The flight instructor stated that during an approach for landing, the landing gear selection handle was placed into the gear down position, and "immediately" he and the duel student pilot noticed electrical smoke and fumes, but there was never a fire. The battery and alternator switches were selected to the off position to vent the cockpit. The flight instructor and the pilot restored electrical power and saw the landing gear up and down position indicator lights were not illuminated, and the landing gear circuit breaker was tripped. They were unable to fully extend the landing gear. The manual landing gear crank handle did not engage and spun freely in both directions and they were unable to fully extend the landing gear. They then performed a gear-up landing on runway 17. Post-accident examination by the Federal Aviation Administration of the main landing gear retraction actuator assembly revealed a broken snap ring within the manual crank extension housing that allowed the actuator worm gear to reposition itself beyond the actuator worm sector travel limits. There was no airplane maintenance record showing that the landing gear actuator assembly had been repaired/overhauled. The airplane had a total time of 6,184.5 hours. According to the Baron 55 and 58 Maintenance Manual, section 5-10-00- 601, dated April 1, 2015, TIME LIMITS/MAINTENANCE CHECKS, TIME LIMITS INSPECTION/CHECK, A. Landing Gear states that the actuator assembly is to be overhauled or replaced every 2,000 hours for gray or green colored assemblies. The assembly that was examined was green colored. ## Aircraft - Registration: [N855T](https://openairdocs.org/deregistered/N855T-2018-06-15), registration cancelled 2018-06-15, S/N TE-928, built 1973 (OpenAirDocs) - Reported make and model: BEECH E-55 - Registry model: [Beech E-55](https://openairdocs.org/model/beech-e-55) (registry code 1152732) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: TE-928 - Year built: 1973 - Airframe hours: 6184.5 - Engines: Continental IO-520-CB 285 horsepower reciprocating; Continental IO-520-CB 285 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Cobra Kai Inc, doing business as Cobra Kai Flight Academy - Registered owner: Cobra Kai Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, July 23, 2016 - Departed: CWC, Wichita Falls, TX - Destination: SPS, Wichita Falls, TX - Flight plan: IFR - Airport: SPS, Sheppard Air Force Base/Wichit, runway 17, 7,021 × 150 ft, asphalt - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 53; injuries: none; commercial, flight instructor, airline transport, flight engineer; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review December 30, 2015; seat: right; restraint: lap only; flight hours: 4,940.7 total, 83.5 in this make and model, 3,967.1 as pilot in command, 89.5 in the last 90 days, 29.7 in the last 30 days, 1.8 in the last 24 hours - Student pilot; age 41; injuries: none; commercial; airplane ratings: multi-engine land; medical: unknown, unknown; seat: left; restraint: lap only; flight hours: 2,990 total, 4 in this make and model, 1,118 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 15 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 95 °F, dew point 64 °F - Altimeter: 29.96 inHg - Observed at: SPS ## 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 20160824007199A](https://openairdocs.org/incident/20160824007199A), Aug 24, 2016: Beech E-55, Wichita Falls, TX, Substantial damage. On August 24, 2016, at approximately 1800 CDT, N855T, a Beech E-55, made a gear up landing at Sheppard afb/Wichita Falls regional airport (sps). The aircraft… ## Docket (4 files) The files NTSB released with the investigation on March 8, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93902. 7.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 6.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40460724&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Maintenance Manual (item 2, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40460725&FileExtension=.PDF&FileName=Maintenance%20Manual-Master.PDF - Record of Correspondence - FAA (item 3, .PDF, 54 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40460726&FileExtension=.PDF&FileName=Record%20of%20Correspondence%20-%20FAA-Master.PDF - Photo (item 4, .PDF, 1 photo, 941 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40460727&FileExtension=.PDF&FileName=Photo-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.