# NTSB DCA83AA029: Lockheed 188C, N1968R, Cold Bay, AK, June 8, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: June 8, 1983, 13:55 local (21:55 UTC)
- Place: Cold Bay, AK
- Coordinates: 55.220092, -162.780105 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=55.2201&lon=-162.7801&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 15 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB office: Major Investigations Division
- NTSB case key (mKey): 15785
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA83AA029
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15785/pdf
- Page: https://openairdocs.org/ntsb/DCA83AA029

## Sequence of events

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

- Airframe/component/system failure/malfunction, climb - to cruise
  - propeller system/accessories - undetermined (cause)
  - propeller system/accessories - vibration
  - propeller system/accessories - separation
  - fuselage,cabin - decompression
  - flight control system - jammed
  - throttle/power lever - disconnected
  - performed, pilot in command
  - precautionary landing - performed, pilot in command

## Analysis

DURING A CRUISE CLIMB, THE AIRCREW NOTED AN UNUSUAL VIBRATION; HOWEVER, ATTEMPTS TO ISOLATE THE VIBRATION WERE UNSUCCESSFUL. WHILE CLIMBING FROM FL190 TO FL250, THE FLT ENGINEER WENT AFT TO OBSERVE THE ENGS & PROPS, BUT NOTED NOTHING UNUSUAL. A FLT ATTENDANT WENT FORWARD TO ADVISE THE CAPT THAT NOTHING WAS OBSERVED, WHEN THE VIBRATION INCREASED IN INTENSITY. AS SHE LEFT THE COCKPIT, SHE PEERED OUT THE RGT WINDOW & SAW THE #4 PROP SEPARATE & STRIKE THE ACFT. THIS CAUSED MAJOR DAMAGE TO THE LOWER FUSELAGE & RESULTED IN DECOMPRESSION OF THE CABIN. THE FLT CONTROLS BECAME JAMMED & THE ENGS WOULD NOT RESPOND TO THROTTLE MOVEMENT. THE AUTOPLT WAS USED FOR MINIMAL CONTROL & THE FLT CREW WERE ABLE TO DIVERT TO ANCHORAGE, AK. THEY WERE ABLE TO CLIMB & DESCEND BY RETRACTING & EXTENDING THE LANDING GEAR WITH THE #2 ENG SHUT DOWN. THE ACFT WAS LANDED SAFETY & THE ENGS WERE SHUT DOWN TO DECELERATE . THE EXACT CAUSE OF THE PROP SEPARATION WAS NOT DETERMINED SINCE IT FELL IN THE OCEAN DURING THE OCCURRENCE.

## Aircraft

- Registration: [N1968R](https://openairdocs.org/deregistered/N1968R-2001-02-21), registration cancelled 2001-02-21, S/N 2007 (OpenAirDocs)
- Reported make and model: LOCKHEED 188C
- Registry model: [Lockheed 188C](https://openairdocs.org/model/lockheed-188c) (registry code 5262604) (OpenAirDocs)
- Category: Airplane
- Serial number: 2007
- Airframe hours: 32994
- Engines: ALLISON 501-D13 4000 horsepower turbo prop
- Damage: Substantial damage
- Fire: On-Ground
- Flight: Part 121
- Registered owner: Reeve Aleutian Airways
- Airworthiness certificate: Standard, Transport
- Last inspection: Continuous airworthiness, June 8, 1983, 8 hours before
- Departed: CDB, COLD BAY, AK
- Destination: SEA, SEATTLE, WA
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 54; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 13,874 total, 5,711 in this make and model, 133 in the last 90 days, 58 in the last 30 days, 8 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 50 statute miles
- Lowest ceiling: none
- Observed at: CDB

## 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 19830608075979A](https://openairdocs.org/incident/19830608075979A), Jun 8, 1983: Lkheed 188C, Cold Bay, AK, Substantial damage. Lost prop assembly and reduction gear box on NR4 engine on climb. Fuselage damaged caused decompression. Landed ok.

## Other investigations on N1968R (1)

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.

- [NTSB ANC73AA023](https://openairdocs.org/ntsb/ANC73AA023), Sep 26, 1972: Lockheed L188A (N1968R), Amchitka Is, AK, substantial damage

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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