# NTSB ATL84LA212: Cessna 172G, N4650L, Grenada, MS, June 30, 1984

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: June 30, 1984, 09:25 local (14:25 UTC)
- Place: Grenada, MS
- Coordinates: 33.770942, -89.81044 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.7709&lon=-89.8104&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 6488
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL84LA212
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/6488/pdf
- Page: https://openairdocs.org/ntsb/ATL84LA212

## Sequence of events

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

- Vortex turbulence encountered, approach - vfr pattern - final approach
  - planned approach - improper, pilot in command (cause)
  - clearance - inadequate, pilot in command (cause)
- Loss of control - in flight, approach - vfr pattern - final approach
- In flight collision with terrain/water, approach - vfr pattern - final approach

## Analysis

DURING ARRIVAL TO AN UNCONTROLLED ARPT, THE PLT MADE AN APCH WHILE FOLLOWING ABOUT 1/4 MI BEHIND A UH-1 HELICOPTER. AT THAT TIME, THERE WAS A QUARTERING HEAD WIND AT ABOUT 4 KTS. WHILE ON FINAL APCH AT AN ALT OF ABOUT 200 FT AGL, THE CESSNA 172 ENCOUNTERED SEVERE TURBULENCE & THE PLT WAS UNABLE TO MAINTAIN FLT. WITNESSES REPORTED THAT THE CESSNA WENT NEARLY INVERTED AFTER ENCOUNTERING WAKE TURBULENCE FROM THE HELICOPTER. THE CESSNA IMPACTED THE GROUND ABOUT 500 FT SHORT OF THE RWY & WAS DAMAGED. THE PLT STATED THAT HE WAS NOT AWARE THAT HELICOPTERS PRODUCED WAKE TURBULENCE. THE AIM ADDRESSES HELICOPTER DOWNWASH & ROTOR VORTICES.

## Aircraft

- Registration: [N4650L](https://openairdocs.org/deregistered/N4650L-2018-08-06), registration cancelled 2018-08-06, S/N 17254645 (OpenAirDocs)
- Reported make and model: CESSNA 172G
- Registry model: [Cessna 172G](https://openairdocs.org/model/cessna-172g) (registry code 2072420) (OpenAirDocs)
- Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 17254645
- Airframe hours: 2554
- Engines: CONTINENTAL O-300-D 145 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: James T. Blanks & J. H. Cruse
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, February 1, 1984
- Departed: HKS, JACKSON, MS
- Destination: M42
- Airport: M42, Grenada Muni., runway 31, 4,845 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 55; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 860 total, 812 in this make and model, 786 as pilot in command, 74 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 340° at 4 knots
- Visibility: 6 statute miles
- Lowest ceiling: none
- Temperature: 81 °F, dew point 66 °F
- Altimeter: 29.00 inHg
- Observed at: GWO, 50 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 19840630029019A](https://openairdocs.org/incident/19840630029019A), Jun 30, 1984: Cessna 172G, Grenada, MS, Substantial damage. Flew into wake turbulence while landing behind an army UH1E.became almost inverted. Impacted level short of runway.

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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