# NTSB MIA84LA028: Grumman American AA-5B, N123EF, Okeechobee, FL, November 11, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: November 10, 1983, 21:40 local (Nov 11, 1983, 02:40 UTC)
- Place: Okeechobee, FL
- Coordinates: 26.529785, -80.190063 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=26.5298&lon=-80.1901&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 31061
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA84LA028
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/31061/pdf
- Page: https://openairdocs.org/ntsb/MIA84LA028

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, cruise
  - engine assembly,valve,intake - failure,total (cause)
- Forced landing, approach
  - attempted, pilot in command
- In flight collision with object, approach - vfr pattern - final approach
  - light condition - dark night (contributing factor)
  - object - wire,transmission (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PLT REPORTED THAT DURING FLT, THE ENG HAD A PARTIAL LOSS OF POWER. HE ATTEMPTED TO DIVERT TO AN ARPT. HE WAS ABLE TO GET ON FINAL APCH, BUT WHEN HE SAW HE COULD NOT REACH THE RUNWAY, HE TURNED AWAY FROM THE LIGHTS & A BUILDING FOR AN EMERGENCY LANDING. HOWEVER, BEFORE LANDING, THE ACFT COLLIDED WITH POWER LINES, THEN IMPACTED THE GROUND. AN EXAM OF THE ENG REVEALED THAT THE EXHAUST VALVE HEAD OF THE #1 CYLINDER HAD SEPARATED. WITH CONTINUED OPERATION OF THE ENG, DEBRIS ENTERED THE #1 CYLINDER CAUSING FURTHER DAMAGE & LOSS OF POWER. THE SODIUM COOLED EXHAUST VALVE, PN 74541 AH-ED, HAD APRX 300 HRS IN SERVICE.

## Aircraft

- Registration: N123EF (not matched to a registry record)
- Reported make and model: GRUMMAN AMERICAN AA-5B
- Category: Airplane
- Serial number: AA5B-0018
- Airframe hours: 2231
- Engines: LYCOMING O-360 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Registered owner: Air Trek, Inc.
- Airworthiness certificate: Standard, Normal
- Departed: PBI, WEST PALM BEACH, FL
- Destination: TPA, TAMPA, FL
- Airport: OBE, Okeechobee, runway 4, 5,000 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 26; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 2,903 total, 302 in this make and model, 2,703 as pilot in command, 450 in the last 90 days, 15 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 210° at 6 knots
- Visibility: 10 statute miles
- Lowest ceiling: 25,000 ft broken
- Temperature: 73 °F, dew point 64 °F
- Altimeter: 29.00 inHg
- Observed at: VRB, 33 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 19831110057289A](https://openairdocs.org/incident/19831110057289A), Nov 10, 1983: Gulstm AA5B, Okeechobee, FL, Substantial damage. Crash occurred during emergency landing at night. Exhaust valve head broke causing power loss.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.