LAX00LA018 · Sikorsky CH-54A
Sikorsky CH-54A · Accident: propeller/rotor contact to person while standing
From YVY · Tooele, UT to Sutter County Airport (O52)
Event
- NTSB case
- LAX00LA018
- 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
- 1 · 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
Sikorsky CH-54A
- Aircraft type
- Sikorsky CH-54
- Category
- Helicopter
- 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
- N9125M
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From YVY · Tooele, UTTo Sutter County Airport (O52), Yuba City, CA
- 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
- Standing · engine(s) not operating
- 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
- Propeller/rotor contact to person
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Cause areas
- Flight engineer › Clearance, not maintained
- Flight engineer › Unsafe/hazardous condition, disregarded
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While the aircraft was shutting down, the flight engineer exited the aircraft, and gave the pilots the signal that the droop stops had engaged. He then climbed up on a stepladder next to the tail boom as the main rotor continued to coast down to a stop. A minute or so later, the two remaining crewmembers heard a 'thump.' The pilot-in-command (PIC) asked the copilot to go outside and find the source of the noise. When he walked toward the rear of the aircraft he found the flight engineer laying across the top of tail boom with a massive head injury. The main rotor of the Ch-54A is fully articulated. The rotor system employs a series of main rotor blade droop stops. As the rotor rpm slows, centripetal force is reduced and the droop stop springs pull the stops back into ground stop position. During spool down it can take 20 seconds or more for the first through sixth stop to move into the ground stop position. The visual strobe effect, caused by the turning rotor head, can make it appear that all the stops are in place when one or more stops still have not yet been fully repositioned. Winds were gusting up to 14 knots at the time of the shutdown. Gusting winds during shutdown can cause a slow turning rotor blade to suddenly flap down independently of the remaining blades.
Probable cause
the flight engineer's decision to climb a step ladder that put him in close proximity to the still turning main rotor blades. The gusting wind was a factor in the accident.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX00LA018
- Event ID
- 20001212X19991
- Case number
- LAX00LA018
- 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, damage. 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: 29bf020c06b62e190e70504c71076600b06ffd59db95bdee11b4406e2165a9f3; retrieved 2026-09-20T21:42:32.669Z.