GAA16CA487 · Cessna 172 P
Land and Sea Aviation Alaska Cessna 172 P · Accident while taxiing
From Merrill Field (MRI) to Merrill Field (MRI)
Event
- NTSB case
- GAA16CA487
- 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
- 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
Cessna 172 P
- Aircraft type
- Cessna 172
- 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
- N52950
- Operator
- Land and Sea Aviation Alaska
- Onboard fatalities
- Unknown
- Route
- From Merrill Field (MRI), Anchorage, AKTo Merrill Field (MRI), Anchorage, AK
- Aircraft age
- About 35 years (built 1981)
- 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
- Taxi · to runway
- 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
- Miscellaneous/other
- 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
- Environmental issues › Physical environment
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The flight instructor reported that during taxi the airplane started to lean to the right, so he looked out of his window to see if the right tire was flat. He further reported that "the ramp was opening up into a 2 foot wide dark black hole" underneath the right main landing gear. The flight instructor and student pilot egressed from the airplane without further incident.
A postaccident examination revealed substantial damage to the empennage.
The flight instructor reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
Photographs provided by Federal Aviation Administration showed that the right main landing gear had broken through the pavement into a sink hole underneath.
Probable cause
The airplane’s encounter with a developing sink hole during taxi on the ramp area.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record GAA16CA487
- Event ID
- 20160914X32900
- Case number
- GAA16CA487
- 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: 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: aebf319781866913faebc6b2d18099e1a4b99e0c0fc953f4fc6657bf31ca8dbb; retrieved 2026-09-16T04:16:07.397Z.