# NTSB CHI08CA177: Robinson R44 II, N31138, Ottawa, IL, July 4, 2008

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: July 4, 2008, 18:20 local (23:20 UTC)
- Place: Ottawa, IL
- Coordinates: 41.399723, -88.793891
- Nearby events: https://openairdocs.org/map.md?lat=41.3997&lon=-88.7939&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute-cruise: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report August 28, 2008
- Report: Approved by Office Director
- Parties: Federal Aviation Administration - Du Page FSDO
- NTSB case key (mKey): 68639
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI08CA177
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/68639/pdf
- Page: https://openairdocs.org/ntsb/CHI08CA177

## Probable cause

The pilot's failure to maintain clearance from the power transmission lines.  Contributing to the accident was the unmarked power transmission lines.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Robinson Helicopter R44 II, 26 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md?model=7640122), [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md)
- [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Robinson Helicopter R44 II, 39 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=7640122), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md)
- [Terrain: water](https://openairdocs.org/ntsb-findings/03021020): Environmental issues › Physical environment · Not specified; cases with it: [Robinson Helicopter R44 II, 4 cases](https://openairdocs.org/ntsb-findings/03021020/cases.md?model=7640122), [All aircraft, 97 cases](https://openairdocs.org/ntsb-findings/03021020/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Enroute-cruise: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470) (defining event); cases with it: [Robinson Helicopter R44 II, 95 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7640122), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)
- [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Robinson Helicopter R44 II, 95 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7640122), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The helicopter impacted unmarked power transmission lines as the pilot maneuvered at a low altitude over a river.  The helicopter impacted the river and separated into several pieces.  The pilot and his passengers were not injured and were rescued by nearby boaters.

## Factual narrative

The helicopter impacted unmarked power transmission lines as the pilot maneuvered at low altitude over a river.  The helicopter impacted the river and separated into several pieces.  The pilot and his passengers were not injured and were rescued by nearby boaters.

## Aircraft

- Registration: [N31138](https://openairdocs.org/deregistered/N31138-2013-09-26), registration cancelled 2013-09-26, S/N 11313, built 2006 (OpenAirDocs)
- Reported make and model: Robinson R44 II
- Registry model: [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii) (registry code 7640122) (OpenAirDocs)
- Registry engine: [Continental IO-540 series](https://openairdocs.org/engine/continental-io-540-series) (registry code 17051, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 11313
- Airframe hours: 546.9
- Engines: Lycoming IO-540-AE1A5 245 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Midwestern Helicopter, LLC.
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, February 1, 2008
- Departed: 8N2, Ottawa, IL
- Destination: 8N2, Ottawa, IL

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; injuries: none; commercial; medical: class 2, without waivers/limitations; last flight review August 1, 2007; seat: right; flight hours: 239 total, 28 in this make and model, 12 in the last 90 days, 6 in the last 30 days, 0 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 30° at 4 knots
- Visibility: 10 statute miles
- Temperature: 79 °F, dew point 54 °F
- Altimeter: 30.01 inHg
- Observed at: VYS, 16 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 20080704843249A](https://openairdocs.org/incident/20080704843249A), Jul 4, 2008: Robsin R44RAVENII, Wedron, IL, Substantial damage. (-23) On July 4, 2008, at about 1820 CDT, at Wedron, Illinois, [privacy data omitted] was pilot-in-command of Robinson R-44, N31138, providing a sight-seeing…

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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