# NTSB DEN84LA153: Grumman G-164A, N9822, Wiggins, CO, May 18, 1984

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 18, 1984, 06:40 local (12:40 UTC)
- Place: Wiggins, CO
- Coordinates: 40.230464, -104.070732 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.2305&lon=-104.0707&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 16382
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN84LA153
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/16382/pdf
- Page: https://openairdocs.org/ntsb/DEN84LA153

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, cruise
  - maintenance,service bulletin/letter - not followed, other maintenance personnel (contributing factor)
  - engine assembly,cylinder - fatigue (cause)
- Forced landing, landing
- Nose over, landing - roll
  - terrain condition - rough/uneven (contributing factor)

## Analysis

WHILE EN ROUTE TO A FIELD FOR AERIAL APPLICATION, AN OIL MIST APPEARED ON THE WINDSHIELD OF THE ACFT. SHORTLY AFTER THAT, THE ENG PROGRESSIVELY LOST POWER & THE PLT MADE A FORCED LANDING IN A PASTURE. DURING THE LANDING ROLL, THE ACFT HIT A HOLE IN THE GROUND & NOSED OVER. AN EXAM OF THE ENG REVEALED THAT THE EXHAUST ROCKER BOX ON THE #1 CYLINDER HAD CRACKED & SEPARATED WHERE THE OIL LINES WERE ATTACHED. THERE WERE 2 PRATT & WHITNEY SERVICE BULLETINS CONCERNING R-1340-AN1 CYLINDERS THAT WERE NOT COMPLIED WITH. SB-1720 RECOMMENDED AN INSPECTION OF THE CYLINDER HEADS DURING OVERHAUL. SB-1743 CALLED FOR REPLACEMENT OF ALL CYLINDERS WITH IMPROVED CYLINDERS HAVING A 5/8 INCH REENFORCEMENT WEB ON THE EXHAUST ROCKER BOX. THE OLD CYLINDERS HAD 1/2 INCH WEB. THE ACFT HAD FLOWN 360 HRS SINCE THE LAST MAJOR OVERHAUL.

## Aircraft

- Registration: [N9822](https://openairdocs.org/deregistered/N9822-2018-01-10), registration cancelled 2018-01-10, S/N 1282, built 1974 (OpenAirDocs)
- Reported make and model: GRUMMAN G-164A
- Registry model: [Grumman Acft ENG Cor-Schweizer G-164A](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164a) (registry code 3952801) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 1282
- Airframe hours: 1900
- Engines: P&W R-1340-AN1 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Low Level Dusting Co. Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, February 15, 1984
- Departed: GXY, GREELEY, CO

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 58; commercial; airplane ratings: single-engine land, multi-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 11,700 total, 3,900 in this make and model, 37 in the last 90 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 55 °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 19840518017819A](https://openairdocs.org/incident/19840518017819A), May 18, 1984: Scwzer G164A, Wiggins, CO, Substantial damage. Crash occurred during emergency landing after engine lost power.

## Other investigations on N9822 (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 CEN12LA513](https://openairdocs.org/ntsb/CEN12LA513), Aug 1, 2012: Grumman Acft ENG Cor G-164A (N9822), La Salle, CO, substantial damage. Probable cause: The loss of engine power due to the detached distributor rotor.

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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