# NTSB BFO90LA080: Cessna 172, N96839, Maryville, KY, September 26, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 26, 1990, 10:30 local (14:30 UTC)
- Place: Maryville, KY
- Coordinates: 38.089382, -85.649818 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.0894&lon=-85.6498&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report November 9, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 11615
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=BFO90LA080
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/11615/pdf
- Page: https://openairdocs.org/ntsb/BFO90LA080

## Probable cause

THE FAILURE OF A HYDRAULIC BRAKE LINE WHICH RESULTED IN A LOSS OF FLUID, AND AN INOPERATIVE BRAKE SYSTEM DURING LANDING ROLL.

## Analysis

THE PILOT REPORTED THAT DURING THE PRELFIGHT, THE LEFT BRAKE WAS 'WEAK.' THE FLUID LEVEL IN THE LEFT BRAKE HYDRAULIC FLUID RESERVOIR WAS LOW AND IT WAS REFILLED. THE BRAKE OPERATED SATISFACTORILY. THE PILOT FLEW THE AIRCRAFT TO KY07 TO FURTHER INSPECT THE BRAKE. DURING THE LANDING, THE PILOT EXPERIENCED A LOSS OF PRESSURE IN THE LEFT BRAKE. THE PILOT GROUND LOOPED THE AIRCRAFT BY APPLYING RIGHT BRAKE. THE AIRCRAFT WENT OFF THE SIDE OF THE RUNWAY, STRUCK A FENCE AND WENT INTO A DITCH. EXAMINATION OF THE AIRCRAFT REVEALED THE LEFT BRAKE LINE WAS WORN THROUGH FROM CHAFING AGAINST A SCREW WHICH SECURES THE STRUT FAIRING.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of control - on ground/water, landing - roll
  - landing gear,normal brake system - inoperative
  - ground loop/swerve - intentional, pilot in command
  - fluid,hydraulic - leak
  - hydraulic system,line - failure,total (cause)
  - hydraulic system,line - chafed

## Aircraft

- Registration: [N96839](https://openairdocs.org/aircraft/N96839), registered now, S/N 17276122, built 1984 (OpenAirDocs)
- Reported make and model: CESSNA 172
- Registry model: [Cessna 172P](https://openairdocs.org/model/cessna-172p) (registry code 2072436) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 17276122
- Engines: LYCOMING O-320 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Ferry, Part 91
- Registered owner: Civil Air Patrol
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, August 26, 1990, 32 hours before
- Departed: LOU, LOUISVILLE, KY
- Airport: runway 27, 1,500 ×  ft, grass/turf

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 67; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Lowest ceiling: none
- Temperature: 81 °F

## 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 19900926046829A](https://openairdocs.org/incident/19900926046829A), Sep 26, 1990: Cessna 172N, Louisville, KY, Substantial damage. Weak brake serviced prior flight went out on landing. Ground looped into a fence. Brake line leaking on strut.

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.

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