# NTSB WPR21LA037: Remos Aircraft Gmbh Flugzeugbau GX, N87GX, Glendale, AZ, November 4, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: November 4, 2020, 12:20 local (19:20 UTC) - Place: Glendale, AZ - Coordinates: 33.526917, -112.29513 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.5269&lon=-112.2951&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: FAA - NTSB case key (mKey): 102241 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA037 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102241/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102241 - Page: https://openairdocs.org/ntsb/WPR21LA037 ## Probable cause The material overstress failure of the airframe’s aluminum carry-through of the main landing gear. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fuselage: gear attach fittings (on fus)](https://openairdocs.org/ntsb-findings/01035343): Aircraft › Aircraft structures · Failure (probable cause); cases with it: [Remos Acft Gmbh Flugzeugbau REMOS GX, 1 case](https://openairdocs.org/ntsb-findings/01035343/cases.md?model=060006H), [All aircraft, 16 cases](https://openairdocs.org/ntsb-findings/01035343/cases.md) - [Fuselage: fuselage attach fittings sys](https://openairdocs.org/ntsb-findings/01035340): Aircraft › Aircraft structures · Failure (probable cause); cases with it: [Remos Acft Gmbh Flugzeugbau REMOS GX, 1 case](https://openairdocs.org/ntsb-findings/01035340/cases.md?model=060006H), [All aircraft, 5 cases](https://openairdocs.org/ntsb-findings/01035340/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Remos Acft Gmbh Flugzeugbau REMOS GX, 3 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=060006H), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis Upon landing, the airplane veered to the left and the flight instructor took control of the airplane, preventing a runway excursion. During the landing, roll a grinding noise occurred and the flight instructor was able to shut down the airplane on a nearby taxiway. A postaccident examination revealed that the aluminum carry-through spar failed in overstress. A portion of the failed carry-through remained attached to the landing gear and breached the composite structure, entering the cabin floor under the passenger seat. About 12 inches of the carry-through structure had separated from the airplane, permitting the horizontal stabilizer and elevator to skid on runway surface, eroding the composite structure. The fracture surfaces exhibited features consistent with overstress and hardness; conductivity measurements were consistent with a material that met the minimum strength requirements for the carry-through. A review of the maintenance records revealed that the manufacturer’s service bulletin for the mandatory inspection had been accomplished. The service bulletin called for the replacement of the carry-through as soon as practical, but, at the latest, after detection of cracks or 800 total landings, which ever came first. The carry-through failure occurred when the airplane had accumulated nearly 437 landings. The accident airplane was operated as a flight training airplane and likely experienced a hard landing during flight training operations, which may have accelerated the carry-through overstress failure. ## Factual narrative On November 04, 2020, at 1220 mountain standard time, a Remos Aircraft GMBH Fleugzebau, GX, N87GX, was substantially damaged when it was involved in an accident near Glendale, Arizona. The certificated flight instructor and the student pilot were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The flight instructor reported that the purpose of the flight was for the student pilot to practice takeoffs and landings. The flight instructor reported that during a landing, the airplane veered left of the runway centerline, and, in response, he took the controls to prevent a runway excursion. The flight instructor noted that maneuvering the airplane back to the runway centerline was difficult. The airplane subsequently made a grinding noise, and they could feel an unusual vibration. The flight instructor was able to maneuver the airplane to the nearest taxiway, where he shut down the airplane. A postaccident examination revealed that the aluminum carry-through of the main landing gear failed during landing. A portion of the failed aluminum carry through remained attached to the landing gear and breached the composite structure, entering the cabin floor under the passenger seat. About 12-inches of the carry through structure had separated from the airplane, permitting the horizontal stabilizer and elevator to skid on runway surface, eroding the composite structure. The failed carry through was sent to the National Transportation Safety Board’s Material Laboratory, and the Senior Material Engineer reported that the carry-through appeared to have failed in overstress. The fracture surfaces all exhibited features consistent with overstress and hardness plus conductivity measurements were consistent with a material that met the minimum strength requirements. A review of the airframe maintenance logbook indicated that all aircraft safety alerts and airworthiness directives for the airframe had been complied with. On December 17, 2009, the manufacturer issued Service Bulletin SB-002-landing-gear for the accident airplane. The service bulletin required the inspection of the aluminum carry through for the main landing gear immediately if there had been a hard landing in the past, within the next 50 landings, and during scheduled maintenance (100-hr, and Annual Condition Inspection), and after any hard landing. During an interview with the recently hired Light Sport Repairman Maintainer, he reported that he completed the required inspection for cracks, specifically near the weight reduction holes on October 29, 2020. During the October 2020 100-hr inspection, the maintainer recalled that there were no visible cracks or signatures of deformation to the carry-through. According to the service bulletin, replacement of the carry-through was required as soon as practical but at the latest after detection of cracks, or after 800 total landings, which ever came first. At the time of the maintainer’s inspection,the airplane had accumulated 402 estimated landings and amassed 317.9 total airframe hours. At the time of the accident, the airplane had accumulated 437 estimated landings. ## Aircraft - Registration: [N87GX](https://openairdocs.org/aircraft/N87GX), registered now, S/N 351, built 2009 (OpenAirDocs) - Reported make and model: REMOS AIRCRAFT GMBH FLUGZEUGBAU GX - Registry model: [Remos Acft Gmbh Flugzeugbau REMOS GX](https://openairdocs.org/model/remos-acft-gmbh-flugzeugbau-remos-gx) (registry code 060006H) (OpenAirDocs) - Registry engine: [Rotax 912ULS series](https://openairdocs.org/engine/rotax-912uls-series) (registry code 55572, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 351 - Year built: 2009 - Airframe hours: 334.8 - Engines: Rotax 912ULS/309120110 100 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Fly Eagle Sport - Registered owner: Culprit Aviation LLC - Airworthiness certificate: Special, Special light-sport (Special) - Last inspection: Condition, October 29, 2020, 16.9 hours before - Destination: Same as departure - Airport: GEU, Glendale Municipal Airport, runway 01, 7,150 × 100 ft, asphalt - Equipment: Electronic multifunction display, Electronic primary flight display, Stall warning system, ADS-B, Angle of attack indicator, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 43; injuries: none; remote, commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane, helicopter; medical: class 2, with waivers/limitations; last flight review March 4, 2019; seat: right; restraint: 4-point; flight hours: 3,374 total, 20.1 in this make and model, 3,238.6 as pilot in command, 25.7 in the last 90 days, 21.3 in the last 30 days, 0.7 in the last 24 hours - Student pilot; age 67; injuries: none; student; medical: with waivers/limitations; seat: left; restraint: 4-point; flight hours: 128.9 total, 68.2 in this make and model, 27 as pilot in command, 32.8 in the last 90 days, 12.9 in the last 30 days, 0.7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Temperature: 82 °F, dew point 37 °F - Altimeter: 30.10 inHg - Observed at: KGEU - METAR: KGEU 041850Z 00000KT 10SM SKC 28/03 A3010 ## 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 20201104015289A](https://openairdocs.org/incident/20201104015289A), Nov 4, 2020: Remos Acft Gmbh Flugzeugbau REMOS GX, Glendale, AZ, Substantial damage. Normal day time flight, on touch down the landing gear collapsed. The pilots evacuated the aircraft. The landing gear support collapsed. There is a Remos… ## Docket (8 files) The files NTSB released with the investigation on July 27, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102241. 5.0 MB in all. - Materials laboratory factual report 21-065 (item 1, PDF, 7 pages, 6 photos, 737 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13157879&FileExtension=pdf&FileName=Materials%20Laboratory%20Factual%20Report%2021-065-Rel.pdf - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 2, PDF, 9 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14056191&FileExtension=pdf&FileName=6120_1_Redacted-Rel.pdf - Student pilot's statement (item 3, PDF, 2 pages, 109 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14058211&FileExtension=pdf&FileName=Student%20Pilot%27s%20Statement_Redacted-Rel.pdf - Record of conversation -lsrm (item 4, PDF, 1 page, 153 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14064828&FileExtension=pdf&FileName=Record%20of%20Conversation-Rel.pdf - Manufacturer service bulletin (item 5, PDF, 4 pages, 76 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14057605&FileExtension=pdf&FileName=SB-002-landing-gear-Rel.pdf - Airframe logbook entry (item 6, PDF, 1 page, 460 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14056301&FileExtension=pdf&FileName=AF%20CI%20102920-Rel.pdf - Estimated airframe landings at time of service bulletin inspection (item 7, PDF, 1 page, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14245579&FileExtension=pdf&FileName=Estimated%20Number%20of%20Landings-Rel.pdf - Photographs (item 8, PDF, 2 pages, 279 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14058466&FileExtension=pdf&FileName=Photographs-Rel.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.