LAX97LA247 · Sikorsky S-58T
Sikorsky S-58T · Accident: total loss of engine power (mechanical failure) while maneuvering
From Page Municipal Airport (PGA) to an unrecorded destination
Event
- NTSB case
- LAX97LA247
- 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
Sikorsky S-58T
- Aircraft type
- Sikorsky S-58
- 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
- N47B
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Page Municipal Airport (PGA)To 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 133: Rotorcraft Ext. Load
- 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 · hover
- 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
- Total loss of engine power (mechanical failure)
- 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
- Turbine assembly › Overtemperature
- Turbine assembly, turbine blade › Fractured
- Unknown › Starting procedure, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot was hovering with an external load, when he heard a loud noise and noticed a power loss. He turned and executed a precautionary landing with a hard touchdown. The main rotor blades flexed downward and impacted the tail boom. An inspection revealed that over half of the blades in the No. 2 power section were fractured. A metallurgical examination revealed that two consecutive blades showed evidence of solutioning and re-solidification; however, the fracture surfaces did not show similar evidence of heat distress. Discoloration was also found on the power turbine wheel at a point corresponding to the location of the two blades. The operator stated that the aircraft had flown about 138 hours since all the turbine blades were replaced. None of the pilots who had flown the aircraft since then reported experiencing any hung or hot starts.
Probable cause
an engine failure resulting from the fracture of two power turbine blades, which had been previously subjected to a hot or hung start.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX97LA247
- Event ID
- 20001208X08433
- Case number
- LAX97LA247
- 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: ae0b2c13c22b95f22c966981a55f98077ff49235d4b25a7026c70368c224ea8e; retrieved 2026-09-22T19:07:03.581Z.