# NTSB CHI83FA362: Grumman Scan Type 30, N7775C, Fond Du Lac, WI, August 5, 1983

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Field investigation · Final report
- Date: August 5, 1983, 08:37 local (13:37 UTC)
- Place: Fond Du Lac, WI
- Coordinates: 44.020732, -88.619255 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=44.0207&lon=-88.6193&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor, 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 12012
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI83FA362
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/12012/pdf
- Page: https://openairdocs.org/ntsb/CHI83FA362

## Sequence of events

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

- Airframe/component/system failure/malfunction, landing
  - landing gear,normal retraction/extension assembly - overload (cause)
  - maintenance,installation - improper, other maintenance personnel
  - landing gear,main gear - loose
- Loss of control - on ground/water, landing

## Analysis

AFTER TAKEOFF, THE AIRCREW FLEW TO THE SOUTHERN END OF LAKE WINNEBAGO WHERE THEY MADE SEVERAL UNEVENTFUL WATER LANDINGS. THEY ESTIMATED THAT THE WIND WAS FROM THE NORTHEAST AT 5 TO 6 KTS. THE WATER WAS DESCRIBED AS SMOOTH WITH ONLY SMALL RIPPLES. ON THE 6TH APCH, THE GEAR HANDLE WAS CHECKED IN THE UP POSITION & THE AMBER GEAR UP INDICATOR LIGHT WAS ILLUMINATED. THE AMPHIBIOUS ACFT TOUCHED DOWN ON THE WATER WITH NO BOUNCE OR PORPOISE. ABOUT 2 OR 3 SECONDS AFTER TOUCHDOWN, THE ACFT YAWED VIOLENTLY TO THE RIGHT & ROLLED LEFT. THE LEFT FLOAT & WING TIP HIT THE WATER & THE LEFT WING SEPARATED. THE HULL ROLLED OVER, BUT THE OCCUPANTS EGRESSED BEFORE THE ACFT SANK. A DIVER NOTED THAT THE RIGHT GEAR WAS EXTENDED. AFTER THE ACFT WAS RECOVERED, THE RIGHT MAIN GEAR ACTUATOR ROD CLEVIS WAS FOUND TO HAVE FRACTURED. THE FRACTURE SURFACE HAD SIGNS OF OVERLOAD FAILURE. THE LOCK NUT HAD BEEN SCREWED TIGHTLY AGAINST THE CLEVIS & THE LOCK NUT THREADS HAD PRODUCED GOUGE MARKS ON THE UNTHREADED PORTION OF THE SHANK OF THE CLEVIS.

## Aircraft

- Registration: [N7775C](https://openairdocs.org/aircraft/N7775C), registered now, S/N 21, built 1964 (OpenAirDocs)
- Reported make and model: GRUMMAN SCAN TYPE 30 (SCAN TYPE)
- Registry model: [Grumman SCAN TYPE 30](https://openairdocs.org/model/grumman-scan-type-30) (registry code 3951602) (OpenAirDocs)
- Registry engine: [Lycoming R680E series](https://openairdocs.org/engine/lycoming-r680e-series) (registry code 41545, reciprocating) (OpenAirDocs)
- Category: Airplane
- Engines: LYCOMING R-680-E 300 horsepower reciprocating
- Damage: Destroyed
- Flight: Instructional, Part 91
- Registered owner: William E. Harrison Jr.
- Airworthiness certificate: Standard, Normal
- Departed: OSH, OSHKOSH, WI
- Airport: OSH, Lake Winnebego

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; airline transport; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 1, unknown; seat: left; flight hours: 10 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 45° at 5 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 70 °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 19830805039429A](https://openairdocs.org/incident/19830805039429A), Aug 5, 1983: Gruman SCANTYPE30, Fond Du Lac, WI, Destroyed. Right main gear actuator rod clevis fractured, allowed gear to extend on water landing. Yawed, wing tip hit water.

## Other investigations on N7775C (2)

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 MIA77FKT43](https://openairdocs.org/ntsb/MIA77FKT43), Jun 4, 1977: Grumman G-44A (N7775C), Okeechobee, FL, substantial damage
- [NTSB LAX67D0036](https://openairdocs.org/ntsb/LAX67D0036), Jul 3, 1966: Grumman G-44A (N7775C), Havasu City, AZ, 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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