# NTSB CHI88DEP05: Griffin Pitts S-1S, N77LG, Rio, WI, July 11, 1988

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: July 11, 1988, 17:30 local (22:30 UTC)
- Place: Rio, WI
- Coordinates: 43.449893, -89.229103 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.4499&lon=-89.2291&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report July 10, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 13877
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI88DEP05
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/13877/pdf
- Page: https://openairdocs.org/ntsb/CHI88DEP05

## Sequence of events

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

- Airframe/component/system failure/malfunction, go-around (vfr)
  - go-around - initiated, pilot in command
  - throttle/power lever,linkage - separation (cause)
- Forced landing, descent - emergency
- Nose over, landing - roll
  - terrain condition - open field
  - landing gear,main gear - overload (contributing factor)

## Analysis

WHEN THE PILOT OF THE AMATEUR BUILT BIPLANE INITIATED A GO-AROUND FROM A VFR APPROACH, HE FOUND THAT HE HAD NO RESPONSE TO THROTTLE APPLICATION. HE THEN EXECUTED AN INTENTIONAL FORCED LANDING IN AN ADJACENT FIELD. DURING THIS LANDING THE AIRCRAFT COLLAPSED A MAIN LANDING GEAR AND NOSED OVER. POST ACC INVEST REVEALED THAT THE THROTTLE LINKAGE WAS BROKEN.

## Aircraft

- Registration: [N77LG](https://openairdocs.org/deregistered/N77LG-2013-05-09), registration cancelled 2013-05-09, S/N 451-H (OpenAirDocs)
- Reported make and model: GRIFFIN PITTS S-1S
- Registry model: [Griffin Lavern H PITTS S-1C](https://openairdocs.org/model/griffin-lavern-h-pitts-s-1c) (registry code 7221169) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 451 H
- Airframe hours: 42
- Engines: LYCOMING O-360-B1A 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Jon Lee Bedessem
- Registered owner: Laverne H Griffin
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, July 24, 1987, 7 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 33; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: front; flight hours: 174 total, 8 in this make and model, 130 as pilot in command, 7 in the last 90 days, 2 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 300° at 7 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 75 °F, dew point 52 °F
- Altimeter: 29.00 inHg
- Observed at: MSN, 22 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 19880711026239A](https://openairdocs.org/incident/19880711026239A), Jul 11, 1988: Amtrpt PITTSSPECS1, Rio, WI, Substantial damage. Missed approach. Forced landing in field. Pilot used to vernior throttle. Unscrewed same by twisting. No mechanical

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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