CHI97LA139 · Piper PA-18-150
Piper PA-18-150 · Accident: loss of control on ground/water during landing
From Alpena County Regional Airport (APN) to PZQ
Event
- NTSB case
- CHI97LA139
- 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-18-150
- 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
- N4056Z
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Alpena County Regional Airport (APN), Alpena, MITo PZQ
- 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
- Landing · landing roll
- 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
- Loss of control on ground/water
- 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
- Landing gear, tailwheel assembly › Disconnected
- Pilot in command › Directional control, not possible
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
According to the pilot, the tailwheel began to shimmy during the landing roll and the tailwheel spring on the left side became disconnected. The airplane spun around 270 degrees and the left wing contacted the runway. The airplane traveled off the right side of the runway prior to coming to rest. The pilot stated the groundspeed was very slow when the spring disconnected which resulted in a lack of rudder authority to control the airplane.
Probable cause
the disconnection of the tailwheel spring which resulted in the pilot's inability to maintain directional control of the airplane.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI97LA139
- Event ID
- 20001208X07878
- Case number
- CHI97LA139
- 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: 38c1476a3e53768adac516fd733cd2cf9c0e486d2123f4f55702885e5ea092f1; retrieved 2026-09-22T19:46:14.025Z.