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MIA91LA152 · Piper PA-28-140

25 May 1991 · FLAMINGO, FL, United States

Piper PA-28-140 · Accident: total loss of engine power (mechanical failure) en route

From St. Petersburg Clearwater International Airport (PIE) to Florida Keys Marathon International Airport (MTH)

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Event

NTSB case
MIA91LA152
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
0 · all aircraft and ground
Ground fatalities
0
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Piper PA-28-140

Aircraft type
Piper PA-28
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N56118
Operator
Unknown
Onboard fatalities
Unknown
Route
From St. Petersburg Clearwater International Airport (PIE), St. Petersburg, FLTo Florida Keys Marathon International Airport (MTH), Marathon, FL
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 91: General Aviation
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
En route · cruise
First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Total loss of engine power (mechanical failure)
Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
Tree(s)
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Engine assembly, valve, intake › Fractured
  • Engine assembly, valve, intake › Undetermined

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

DURING NORMAL CRUISE FLT, THE ENG RPM DROPPED FROM 2,400 TO 1,900. THE PLT ATTEMPTED TO CORRECT THIS BUT WAS UNSUCCESSFUL. UNABLE TO MAINTAIN ALTITUDE, HE LANDED THE ACFT IN A FIELD BUT DURING THE LANDING ROLL, THE LT WING WAS SEVERED AFTER IMPACT WITH A TREE. THE ACFT ROLLED INVERTED & CAME TO REST. EXAM OF THE ENG REVEALED THAT THE NO. 3 CYLINDER EXHAUST VALVE FAILED. DUR TO DAMAGE TO THE FRACTURE SURFACE, NO DETERMINATION COULD BE MADE AS TO THE REASON FOR THE FAILURE. REVIEW OF THE ENG LOGBOOKS REVEALED THAT IN OCTOBER 1979, THE EGN WAS OVERHAULED WHICH INCLUDED IN PART, REPLACEMENT OF THE EXHAUST VALVES. SINCE THAT TIME THE ENG HAD ACCUMULATED APRX 1,400 HRS.

Probable cause

PARTIAL LOSS OF ENGINE POWER DUE TO FAILURE OF THE NO. 3 CYLINDER EXHAUST VALVE FOR UNDETERMINED REASONS. CONTRIBUTING TO THE ACCIDENT WAS LACK OF SUITABLE TERRAIN DURING THE FORCED LANDING.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record MIA91LA152
Event ID
20001212X17082
Case number
MIA91LA152
Dataset
historical-pre2008
Source SHA-256
89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: 4943a34ef4894867331cb0dcb1b15d5ba303fdb44451d920e2e967500eeea7da; retrieved 2026-09-21T23:35:12.053Z.