SEA06LA124 · Hughes 369D
Hughes 369D · Accident: loss of engine power while maneuvering
From Skypark Airport (KBTF) to Skypark Airport (KBTF)
Event
- NTSB case
- SEA06LA124
- 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
Hughes 369D
- Aircraft type
- Hughes 369
- 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
- N88SE
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Skypark Airport (KBTF), Bountiful, UTTo Skypark Airport (KBTF), Salt Lake City, UT
- 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 out of ground effect
- 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
- Loss of engine power
- 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
- Reason for occurrence undetermined
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While placing an air conditioning unit on top of a commercial building, the pilot heard the main rotor pitch droop, and confirmed that the rotor rpm was beginning to decrease. He then confirmed the throttle was open in the full flight position, moved the load away from the personnel on the roof, and lowered the collective. The low rotor audio sounded, and the rotor rpm continued to decrease, so the pilot hit the load release switch and autorotated to an emergency landing on top of the roof. After a hard touchdown, the aircraft bounced, touched down again, and then balanced on the right skid before very slowly rolling onto its right side. The load he was placing on the roof weighed less than one-half of what the helicopter was capable of lifting under the ambient conditions, and neither an engine/airframe inspection nor a test run of the engine were able to establish any anomalies or the initiating factor in the rotor droop event.
Probable cause
A loss of rotor rpm for undetermined reasons, resulting in a hard landing on top of the commercial building over which the helicopter was working.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA06LA124
- Event ID
- 20060711X00914
- Case number
- SEA06LA124
- 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: 297fe2ecb5742d3759a17f8b7b6e87be39fb7a972697eb052e1d4af2e51e36c7; retrieved 2026-09-22T04:44:07.878Z.