ANC91IA046 · Nihon YS-11A-600
Reeve Aleutian Airways Nihon YS-11A-600 · Incident: gear not extended during landing
Event
- NTSB case
- ANC91IA046
- 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
- Incident
- 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
Nihon YS-11A-600
- Aircraft type
- Nihon YS-11
- 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
- N173RV
- Operator
- Reeve Aleutian Airways
- Onboard fatalities
- Unknown
- Route
- From not recordedTo 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
- Landing
- 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
- Gear not extended
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Minor
Cause areas
- Company maintenance personnel › Maintenance, major repair, improper
- Landing gear, nose gear assembly › Jammed
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE CREW OF FOUR WERE ON A TRAINING FLIGHT AND WERE PREPARING TO PERFORM APPROACH TO LANDING STALLS. DURING THE MANEUVER, THEY NOTICED THE NOSE GEAR WOULD NOT EXTEND. UNABLE TO EXTEND THE NOSE GEAR, THEY LANDED WITH THE NOSE GEAR UP CAUSING MINOR DAMAGE TO THE AIRPLANE. SUBSEQUENT EXAMINATION REVEALED THAT THE RIVETS WHICH RETAIN THE CENTERING CAM SHEAR PINS WERE SHEARED. THE SHEAR PINS WERE NOT SHEARED. AN EXAMINATION BY MITSUBISHI HEAVY INDUSTRIES, NAGOYA AIRPLANE WORKS, INDICATED THAT THE SHEAR PINS MAY HAVE BEEN INSTALLED IN REVERSE. THE OVERHAUL MANUAL ALSO CONTAINED AMBIGUOUS INFORMATION CONCERNING THE INFORMATION. THE GRAPHICAL DISPLAY SHOWED THE INSTALLATION INCORRECTLY, BUT THE TEXT EXPLAINED THE INSTALLATION CORRECTLY.
Probable cause
A JAMMED NOSE GEAR DUE TO INCORRECT INSTALLATION OF THE SHEAR PIN. CONTRIBUTING TO THE ACCIDENT WAS THE INSUFFICIENTLY DEFINED MAINTENANCE PROCEDURE.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC91IA046
- Event ID
- 20001212X16526
- Case number
- ANC91IA046
- 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: bdddbf2f283d6eabc35507a2d67884ddb75229d5808e1d2f4beb273adae53ad0; retrieved 2026-09-23T04:30:21.303Z.