CEN20CA416 · Cessna 172RG
Purdue Aviation Cessna 172RG · Accident: system/component malfunction/failure (non-power) en route
From Purdue University Airport (KLAF) to an unrecorded destination
Event
- NTSB case
- CEN20CA416
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- Event fatalities
- Unknown
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Cessna 172RG
- Aircraft type
- Cessna 172
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N6330V
- Operator
- Purdue Aviation
- Onboard fatalities
- Unknown
- Route
- From Purdue University Airport (KLAF), Lafayette, INTo not recorded
- Aircraft age
- About 52 years (built 1968)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- System/component malfunction/failure (non-power)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft systems
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
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.
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN20CA416
- Event ID
- 20200922X00441
- Case number
- CEN20CA416
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, cause areas. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: b134bb92925d22297dfc413e7eb36c68b25aa67a0b1f682aae8f125a75548f06; retrieved 2026-09-16T13:05:28.729Z.