# NTSB CHI91FA152: Short Brothers SD3-60, N715NC, Chicago, IL, May 11, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Field investigation · Final report
- Date: May 11, 1991, 15:18 local (20:18 UTC)
- Place: Chicago, IL
- Location: 41.9769° N, 87.9081° W: Placed by OpenAirDocs at CHICAGO O'HARE INTL (ORD), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=41.9769&lon=-87.9081&mi=10
- Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 21 uninjured
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 14901
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI91FA152
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14901/pdf
- Page: https://openairdocs.org/ntsb/CHI91FA152

## Probable cause

THE FAILURE OF THE NOSE WHEEL STEERING HYDRAULIC LINE DURING AFTER LANDING GROUND OPERATIONS.  A RELATED FACTOR IS THE MANUFACTURER'S INADEQUATE INSPECTION AND/OR REPLACEMENT STANDARDS.

## Sequence of events

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

- Airframe/component/system failure/malfunction, taxi - from landing
  - hydraulic system,line - ruptured (cause)
  - acft/equip,inadequate standard/requirement, manufacturer (contributing factor)
  - fluid,hydraulic - loss,partial
  - nosewheel steering - unavailable
  - brakes(normal) - unavailable
- On ground/water collision with object, taxi - from landing
  - object - utility pole

## Analysis

THE PILOT REPORTED THAT DURING POST LANDING TAXI OPERATIONS, HE WAS UNABLE TO STEER THE AIRPLANE OR APPLY NORMAL BRAKES.  THE AIRPLANE DEPARTED THE TAXIWAY, AND RAN ACROSS A GRASS MEDIAN AND SERVICE ROAD BEFORE IT IMPACTED A LIGHT POLE AND CAME TO A STOP.  POST ACCIDENT INVESTIGATION REVEALED A FAILED NOSEWHEEL STEERING HYDRAULIC LINE, WHICH ALLOWED SYSTEM FLUID TO BE PORTED OVERBOARD INTO THE NOSE WHEELWELL.  FURTHER EXAMINATION REVEALED THE LINE FAILED AS A RESULT OF A PUNCTURE OF THE INTERNAL HOSE BY THE WORN/FRAYED OUTER BRAID.  RECORDS INDICATE THE FAILED LINE WAS ORIGINAL EQUIPMENT AND HAD OPERATED THROUGH 17,969 HOURS AND 21,324 CYCLES.

## Aircraft

- Registration: N715NC (not matched to a registry record)
- Reported make and model: SHORT BROTHERS SD3-60
- Category: Airplane
- Serial number: SH-3610
- Airframe hours: 17887
- Engines: P&W PT6A-65AR 1424 horsepower turbo prop
- Damage: Substantial damage
- Flight: Part 121
- Operator: Simmons Airlines/Am.Eagle
- Last inspection: AAIP, April 28, 1991, 82 hours before
- Departed: RFD, ROCKFORD, IL
- Flight plan: IFR
- Airport: ORD, O'Hare International

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; flight hours: 7,758 total, 2,990 in this make and model, 197 in the last 90 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 200° at 10 knots
- Visibility: 7 statute miles
- Lowest ceiling: 4,500 ft broken
- Temperature: 84 °F, dew point 68 °F
- Altimeter: 30.00 inHg
- Observed at: ORD, 1 nm away

## 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 19910511021439A](https://openairdocs.org/incident/19910511021439A), May 11, 1991: Stbros SD360, Chicago, IL, Substantial damage. Lost nose wheel steering on turnoff high speed taxiway. Struck light pole. Hydraulic line worn frayed had ruptured.

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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