ANC18FA044 · Piper PA18
Piper PA18 · Accident: aerodynamic stall/spin while maneuvering
From Sitka Seaplane Base (A29) to Sitka Seaplane Base (A29)
Event
- NTSB case
- ANC18FA044
- 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
- Unknown
- 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 PA18
- Aircraft type
- Piper PA18
- 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
- N1203A
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Sitka Seaplane Base (A29), Sitka, AKTo Sitka Seaplane Base (A29), Sitka, AK
- Aircraft age
- About 67 years (built 1951)
- 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
- Maneuvering
- Defining eventThe 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
- Aerodynamic stall/spin
- 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
- Aircraft › Aircraft oper/perf/capability
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot was flying a lodge client on a wildlife viewing flight in a floatplane. About 2 hours after the planned return time, the airplane was reported overdue and a search was coordinated. The airplane wreckage was located nose down in a confined shallow river the next day. The airplane did not have GPS, ADS-B or a recording system, and there was no radar coverage in the area of the accident; therefore, the flight track was unknown.
The airplane impacted the river bottom in a 70 ° nose down attitude with the front floats absorbing much of the energy and the aft fuselage displaced and twisted right, indicative of impact during a stall/spin. All flight controls were intact and continuous, and the engine exhibited no anomalies. The propeller blades exhibited rearward bends with torsional twist and some chordwise scrapes, and propeller strikes were evident on deadfall trees trunks at the initial impact site, which are all indications of impact with engine power. The right fuel tank cap was not located but given that there was evidence of engine power at impact, it is unlikely that fuel siphoning/exhaustion was causal. It is likely that the pilot was maneuvering the airplane in slow flight to show the passenger wildlife, and, in doing so, exceeded the airplane's critical angle of attack, resulting in the stall.
The airplane was equipped with 4-point shoulder harnesses on both seats; however, first responders reported that the pilot did not have the shoulder harness fittings inserted into the lapbelt buckle. The rear seat passenger was ejected during the impact and examination of the shoulder harnesses for his seat revealed no indication of deformation of the webbing or metal end fittings, indicating he was also likely not using the shoulder harnesses at the time of impact. His lapbelt buckle however, was deformed although it was fully functional. It is possible that the use of the shoulder harnesses may have prevented the rear seat passenger's ejection and/or mitigated some of the occupants' injuries had they been in use at the time of the accident.
Probable cause
The pilot's exceedance of the airplane's critical angle of attack for unknown reason, which resulted in an aerodynamic stall and a loss of control.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC18FA044
- Event ID
- 20180611X23020
- Case number
- ANC18FA044
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2018-06-09.
- API snapshot SHA-256: c612232335c2814961c048a29b28cc11216ada160b356d1bac7c0fbac95202a3; retrieved 2026-09-15T06:42:25.216Z.