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ERA12FA484 · Cessna 172M

25 Jul 2012 · San Juan, PR, United States

Cessna 172M · Accident: system/component malfunction/failure (non-power) on approach

From Antonio Nery Juarbe Pol Airport (TJAB) to Fernando Luis Ribas Dominicci Airport (TJIG)

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Event

NTSB case
ERA12FA484
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
API-reported fatalities
1 · all aircraft and ground
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 172M

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
N73115
Operator
Unknown
Onboard fatalities
Unknown
Route
From Antonio Nery Juarbe Pol Airport (TJAB), Arecibo, PRTo Fernando Luis Ribas Dominicci Airport (TJIG), San Juan, PR
Aircraft age
About 36 years (built 1976)
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
Approach · VFR pattern final
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 oper/perf/capability
  • Aircraft › Aircraft systems
  • Personnel issues › Task performance

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

About 4 minutes before the accident, the pilot advised an air traffic controller that an aileron cable had broken but that he was continuing to the airport to land. Security video and eyewitness reports revealed that the airplane was at low altitude and appeared to be maintaining level flight until it banked right, descended, and impacted water near the airport in a right-wing-down attitude.

A postaccident examination of the wreckage indicated that all of the airplane's flight control cables were lubricated except for a fractured section of aileron control direct cable near the doorpost pulley, which was likely not properly lubricated. Most of the cable strands and the doorpost pulley and bearing exhibited severe corrosion near the fracture. When manipulated by hand, the pulley bearing would not rotate due to the corrosion. Analysis of the cable, doorpost pulley, and an exemplar cable from a similar make and model aircraft that had been flown in similar atmospheric conditions (in what is considered a severe corrosion zone) revealed moderate to severe corrosion. It is likely that, during the airplane's maintenance inspection 6 months before the accident, the mechanic failed to detect the corroded cable due to the difficulty in visually seeing the cable. It is also likely that the doorpost pulley's failure to rotate resulted in tension on the right aileron control cable, which subsequently caused it to fail due to the severe corrosion. The aircraft manufacturer's maintenance manual for the airplane gives specific instructions for lubricating and inspecting flight control cables and pulleys every 600 hours or 12 months, whichever comes first, including, in part, examining the cables for corrosion and the pulleys to ensure smooth rotation. After the accident, the manufacturer produced a video emphasizing the importance of properly examining and lubricating the cables.

Probable cause

Maintenance personnel’s improper lubrication of the right direct aileron control cable and failure to detect the severe corrosion of the cable during a maintenance inspection, which resulted in the in-flight failure of the cable, the pilot’s subsequent inability to maintain aircraft control, and the airplane’s impact with terrain.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record ERA12FA484
Event ID
20120726X21557
Case number
ERA12FA484
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. 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: 9985bb2d4ea105737320271e01b0045323da8287bd966efeae27a994eef554e6; retrieved 2026-09-13T22:30:58.606Z.