MKC89FA063 · Piper PA-18
Scott Aero Service Piper PA-18 · Accident: airframe, component or system failure en route
From PERRY, AR to an unrecorded destination
Event
- NTSB case
- MKC89FA063
- 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
- 2 · 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-18
- Aircraft type
- Piper PA-18
- 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
- N7580D
- Operator
- Scott Aero Service
- Onboard fatalities
- Unknown
- Route
- From PERRY, ARTo not recorded
- 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
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Wing, bracing strut › Corroded
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
TWO WITNESSES HEARD A LOUD NOISE FROM THE ACFT AS IT WAS IN FLT. THEY LOOKED UP & NOTED THE LEFT WING OF THE ACFT HAD FAILED. SUBSEQUENTLY, THE ACFT SPUN TO THE GND & CRASHED IN A WOODED AREA. AN EXAM OF THE WRECKAGE REVEALED THE LEFT FORWARD LIFT STRUT HAD FAILED, APRX 6 INCHES FROM WHERE IT WAS ATTACHED TO THE FUSELAGE. A METALLURGICAL EXAM REVEALED THE INSIDE OF THE STRUT HAD BECOME CORRODED & THE STRUT HAD FAILED IN AN AREA WHERE ITS WALL HAD CORRODED TO A KNIVE EDGE (LESS THAN 0.001 INCH). THE THICKNESS OF THE NON-CORRODED PORTION OF THE WALL WAS 0.38 INCH. A CHEMICAL TEST OF THEINSIDE SURFACE SHOWED THE PRESENCE OF A CORROSION INHIBITOR (VAL-OIL) IN THE NON-CORRODED AREAS. HOWEVER, NO INHIBITOR COULD BE FND WHERE SEVERE CORROSION HAD OCCURRED. TWO FAINT LINES RESEMBLING WATER MARKS WERE FND IN THE STRUT. LOG BOOKENTRIES SHOWED THAT AD 77-03-08 & PIPER SVC BULLETIN #528B HAD BEEN COMPLIED WITH. A TOXICOLOGY CHECK OF THE PLT'S BLOODWAS POSITIVE FOR ALCOHOL (0.04%), BUT THERE WAS NO INDCN THAT THIS WAS RELATED TO THE STRUT FAILURE.
Probable cause
SEVERE CORROSION OF THE LEFT FORWARD WING LIFT STRUT WHICH RESULTED IN THE IN-FLIGHT SEPARATION OF THE LEFT WING. A CONTRIBUTING FACTOR WAS INADEQUACY OF THE APPLICABLE SERVICE BULLETIN.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record MKC89FA063
- Event ID
- 20001213X27780
- Case number
- MKC89FA063
- 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: f4027331bc24bb9fadf29b7a4ef0abf68d29ed1686ae7e022b38a2cee4058ebc; retrieved 2026-09-21T03:23:52.650Z.