# NTSB CEN12LA676: Flight Design Ctls, N21ZA, Elyria, OH, July 20, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 19, 2012, 22:00 local (Jul 20, 2012, 02:00 UTC) - Place: Elyria, OH - Coordinates: 41.344165, -82.17778 - Nearby events: https://openairdocs.org/map.md?lat=41.3442&lon=-82.1778&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Abnormal runway contact](https://openairdocs.org/ntsb-events/090) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 15, 2014 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA-Cleveland FSDO - NTSB case key (mKey): 85400 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12LA676 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/85400/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=85400 - Page: https://openairdocs.org/ntsb/CEN12LA676 ## Probable cause The pilot’s misjudged landing flare, which resulted in a hard landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Flight Design CTLS, 22 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=060005B), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: landing flare](https://openairdocs.org/ntsb-findings/01062041): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Flight Design CTLS, 10 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md?model=060005B), [All aircraft, 1,285 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md) - [Manufacture/production: equipment manufacture](https://openairdocs.org/ntsb-findings/04013010): Organizational issues › Development · Manufacturer; cases with it: [Flight Design CTLS, 2 cases](https://openairdocs.org/ntsb-findings/04013010/cases.md?model=060005B), [All aircraft, 36 cases](https://openairdocs.org/ntsb-findings/04013010/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: Abnormal runway contact](https://openairdocs.org/ntsb-events/090) (defining event); cases with it: [Flight Design CTLS, 3 cases](https://openairdocs.org/ntsb-events/090/sequence.md?model=060005B), [All aircraft, 1,506 cases](https://openairdocs.org/ntsb-events/090/sequence.md) ## Analysis The pilot reported that, on the day of the accident, he had accomplished three landings in the accident airplane and that he was pleased with these landings. Forty-five minutes after the last day landing, he took off for a night flight. During the first attempted landing, he misjudged the flare, and the airplane bounced. He subsequently performed a go-around and again misjudged the landing flare. The airplane subsequently bounced hard on the runway, which resulted in a flat nosewheel tire and firewall and right main landing gear damage. Although examination of the right main landing gear leg revealed several manufacturing defects that have since been addressed by the landing gear leg manufacturer, the accident was likely caused by the pilot's misjudged landing flare, which resulted in a hard landing and the subsequent right main landing gear damage. ## Factual narrative On July 19, 2012, about 2200 eastern daylight time, a Flight Design GMBH model CTLS, N21ZA, sustained substantial damage while landing on runway 7 at the Lorain County Airport (LPR), Elyria, Ohio. The private pilot who was the sole occupant was not injured. The airplane sustained damage to the landing gear, engine mount and firewall during the mishap. The aircraft was registered to RAS Aviation LLC, Elyria, Ohio, and operated by Zone Aviation, Elyria, Ohio, under the provisions of 14 Code of Federal Regulations Part 91. The airplane was rented by the pilot for a personal flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The local flight originated at an unconfirmed time. The accident was not initially reported to authorities and was discovered while investigating another incident that happened with this airplane. On October 17, 2012, about 1330 the airplane sustained minor damage while landing on runway 25 at LPR (CEN13IA024). In both instances, the right composite landing gear leg fractured. Regarding the July accident, the pilot reported that he was performing takeoff and landing practice. He performed 3 landings during the daylight and he reported that he was pleased with these landings. After a 45 minute break he took off again to perform night landings to regain night currency requirements. He reported that on the first night landing he misjudged the landing and bounced. He performed a go-around and came back in for another landing. He again misjudged the landing and "bounced hard". The airplane came back down striking the nose wheel. As the airplane came to a stop the pilot realized there was something wrong and upon de-planing, discovered a flat nose tire. He pushed the airplane from the runway and acquired a tow from ramp personnel. The damaged right main landing gear leg was retained for further examination. The main landing gear leg was made of composite material. The fiber reinforcements used in the composite construction included unidirectional glass fibers, glass fiber fabric, and basalt fiber fabric. Flexible plastic tubes extended the length of the legs enclosed within ribbed plastic tubes located near the leading and trailing edges of the leg. Foam filled space between the plastic tubes and a center internal cavity. The legs were manufactured in a mold with the split line at the leading and trailing edges. During the layup process, layers were placed in a mold half representing the upper half of the leg, and layers were wrapped around the internal tubes, foam, center cavity, and preformed layers. The mold was then closed with a mold piece representing the lower half of the landing gear, and the center internal cavity was pressurized during curing. Examination and sectioning of the landing gear leg showed wrinkling of the fibers resulting in their orientation being angled with relation to the surface rather than parallel to the surface. Additionally several layersterminated at the leading and trailing edges. The location of theses terminating layers corresponded with the location of longitudinal cracks found along the leading and trailing edges of the landing gear. As a result of the investigation, the manufacturer of the airplane was contacted regarding the landing gear manufacturing process. The landing gear legs were manufactured by a sub-contractor to the airplane manufacturer. The airplane manufacture conducted an audit of the sub-contractor and determined that there were some previous quality issues with regard to mold closing during the manufacture of the landing gear legs. It was reported that the landing gear manufacturer had recognized these issues and had implemented steps to reduce the risk of recurrence of these issues. The airplane manufacturer also conducted a search of part requests and difficulty reports related to the main landing gear. This records search showed 3 occurrences which resulted in complete collapse of the landing gear leg out of a fleet of 370 airplanes. All other reported landing gear leg fractures were discovered either during inspection after a hard landing, or during taxi operation when significantly reduced stiffness was encountered. ## Aircraft - Registration: [N21ZA](https://openairdocs.org/aircraft/N21ZA), registered now, S/N F-10-09-04, built 2011 (OpenAirDocs) - Reported make and model: FLIGHT DESIGN CTLS - Registry model: [Flight Design CTLS](https://openairdocs.org/model/flight-design-ctls) (registry code 060005B) (OpenAirDocs) - Registry engine: [Rotax 912ULS series](https://openairdocs.org/engine/rotax-912uls-series) (registry code 55572, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: F-10-09-04 - Engines: Rotax 912 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Zone Aviation - Registered owner: RAS Aviation LLC - Airworthiness certificate: Special, Special light-sport (Special) - Departed: LPR, Elyria, OH - Destination: LPR, Elyria, OH - Airport: LPR, Lorain County Regional Airport, runway 07, 5,002 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; seat: left; flight hours: 119 total, 48 in this make and model, 59 as pilot in command, 1 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night - Wind: 70° at 9 knots - Visibility: 9 statute miles - Lowest ceiling: none - Temperature: 73 °F, dew point 68 °F - Altimeter: 29.90 inHg - Observed at: LPR ## 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 20120719025239A](https://openairdocs.org/incident/20120719025239A), Jul 19, 2012: Flight Design Gmbh CTLS, Elyria, OH, Substantial damage. On 7/19/2012, landed hard on the nose landing gear. This damaged the nose landing gear, engine mount, firewall, and the right main landing gear. The damage to… ## Other investigations on N21ZA (2) 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. - [NTSB GAA19CA049](https://openairdocs.org/ntsb/GAA19CA049), Nov 4, 2018: Flight Design Ctls (N21ZA), Elyria, OH, substantial damage. Probable cause: The pilot's failure to maintain adequate airspeed during landing in variable gusting crosswind conditions, which resulted in a hard landing and runway excursion. - [NTSB CEN13IA024](https://openairdocs.org/ntsb/CEN13IA024), Oct 17, 2012: Flight Design Ctls (N21ZA), Elyria, OH, incident, minor damage. Probable cause: The manufacturing defects in the main landing gear leg, which resulted in its eventual failure. ## Docket (3 files) The files NTSB released with the investigation on October 27, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=85400. 2.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 802 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40418214&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Materials Laboratory 15 - Factual Report 13-002 (with images) (item 2, .PDF, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40386073&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%2013-002%20(with%20images)-Master.PDF - Evidence control form (item 3, .PDF, 66 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40418215&FileExtension=.PDF&FileName=Evidence%20control%20form-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.