# NTSB CEN20CA416: Cessna 172RG, N6330V, Lafayette, IN, September 21, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Data collection · Final report - Date: September 21, 2020, 14:50 local (18:50 UTC) - Place: Lafayette, IN - Coordinates: 40.419727, -86.89064 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.4197&lon=-86.8906&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 102028 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN20CA416 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102028/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102028 - Page: https://openairdocs.org/ntsb/CEN20CA416 ## Probable cause The separation failure of a landing gear system hydraulic line and its compression fitting during cruise flight, which resulted in a partial gear up landing. ## 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: [Cessna 172RG, 10 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=2072438), [All aircraft, 416 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md) - [Landing gear system: main landing gear](https://openairdocs.org/ntsb-findings/01023210): Aircraft › Aircraft systems · Inoperative (probable cause); cases with it: [Cessna 172RG, 4 cases](https://openairdocs.org/ntsb-findings/01023210/cases.md?model=2072438), [All aircraft, 241 cases](https://openairdocs.org/ntsb-findings/01023210/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Cessna 172RG, 11 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=2072438), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Enroute-cruise: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Cessna 172RG, 1 case](https://openairdocs.org/ntsb-events/060/sequence.md?model=2072438), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [Cessna 172RG, 11 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=2072438), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The flight instructor (CFI) and student were airborne for about 10 minutes, in straight and level flight, when they heard and felt a “clunk” followed by the sound of the landing gear pump running continuously. They attempted to lower the landing gear and it did not come down. They subsequently smelled a burning odor, which was assessed to be from the landing gear pump, so they pulled the landing gear circuit breaker. They followed the landing gear manual extension checklist and troubleshot the problem, but there was no pressure in the manual pump and the landing gear would not extend. The CFI then performed a low pass over the runway and tower personnel advised that the nose gear appeared down and both main landing gear appeared partially extended. The CFI then performed a gear up landing during which the left main landing gear collapsed, resulting in substantial damage to the left horizontal stabilizer spars and the rear bulkhead. The CFI surmised that the right main landing gear locked down during the flare. The wreckage was examined, and the nose gear up hydraulic line was found failed. The line had separated from the compression fitting on one end, which resulted in a loss of hydraulic fluid. The manual pump in the landing gear system utilizes the same landing gear hydraulics as the normal extension system, so the loss of hydraulic fluid rendered it inoperable and made it unlikely for all the landing gear to extend and lock down. The failed hydraulic line was installed in the airplane in May, 1993, and had 6,776.2 total hours since installation. The failed hydraulic line was replaced, the airplane was placed on jacks, and the landing gear was swung and functionally tested using both the normal extension/retraction procedures and the manual/emergency extension procedures. The gear operated normally with each procedure and no additional failures or leaks were noted. ## Aircraft - Registration: [N6330V](https://openairdocs.org/aircraft/N6330V), registered now, S/N 172RG0628 (OpenAirDocs) - Reported make and model: Cessna 172RG (No Series) - Registry model: [Cessna 172RG](https://openairdocs.org/model/cessna-172rg) (registry code 2072438) (OpenAirDocs) - Category: Airplane - Serial number: 172RG0628 - Year built: 1968 - Airframe hours: 10041 - Engines: Lycoming O-360 reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Purdue Aviation Llc - Registered owner: Purdue Aviation Llc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 8, 2020 - Departed: KLAF, Lafayette, IN - Destination: Same as departure - Airport: LAF, Purdue University Airport, runway 10, 6,600 × 150 ft, asphalt - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 22; injuries: none; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review August 31, 2020; seat: right; restraint: 3-point; flight hours: 1,415 total, 23 in this make and model, 1,314 as pilot in command, 560 in the last 90 days, 106 in the last 30 days, 4 in the last 24 hours - Student pilot; age 20; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review July 1, 2020; seat: left; restraint: 3-point; flight hours: 186 total, 16 in this make and model, 157 as pilot in command, 76 in the last 90 days, 27 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 68 °F, dew point 43 °F - Altimeter: 26.00 inHg - Observed at: KLAF ## 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 20200921016169A](https://openairdocs.org/incident/20200921016169A), Sep 21, 2020: Cessna 172RG, West Lafayette, IN, Substantial damage. On September 21, 2020, approximately 1230 EST, N6330V, a Cessna 172RG, departed Purdue University Airport (laf) under the provisions of title 14 CFR part 91,… ## Docket (6 files) The files NTSB released with the investigation on August 16, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102028. 2.7 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11428924&FileExtension=pdf&FileName=6120.1%20Pilot_Operator%20Aircraft%20Accident_Incident%20Report-N6330V%20Completed_Redacted-Rel.pdf - Record of conversation - CFI (item 2, PDF, 1 page, 23 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11427898&FileExtension=pdf&FileName=Record%20of%20Phone%20Conversation-CFI-Rel.pdf - Record of conversation - maintenance (item 3, PDF, 1 page, 23 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11429939&FileExtension=pdf&FileName=Record%20of%20Phone%20Conversation-Maintenance-Rel.pdf - Record of conversation - student (item 4, PDF, 1 page, 23 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11429865&FileExtension=pdf&FileName=Record%20of%20Phone%20Conversation-Student%20Pilot-Rel.pdf - Maintenance records (item 5, PDF, 2 pages, 175 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11431507&FileExtension=pdf&FileName=MX%20Binder_Redacted-Rel.pdf - Photos (item 6, PDF, 3 pages, 3 photos, 217 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11431678&FileExtension=pdf&FileName=Photo%20Array%20CEN20LA416-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.