WPR17LA158 · Enstrom F 28C
Enstrom F 28C · Accident: loss of control in flight on approach
From Chino Airport (CNO) to Chino Airport (CNO)
Event
- NTSB case
- WPR17LA158
- 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
Enstrom F 28C
- Aircraft type
- Enstrom F-28
- 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
- N5697B
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Chino Airport (CNO), Ontario, CATo Chino Airport (CNO), Ontario, 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
- Approach · VFR pattern downwind
- 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
- Loss of control in flight
- 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
- Aircraft › Aircraft oper/perf/capability
- Aircraft › Aircraft propeller/rotor
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The solo student pilot reported that he entered the downwind leg to set up for the helicopter's first landing of the day. When abeam the touchdown location, he conducted the prelanding checks with no anomalies noted. Before turning onto the base leg, the pilot lowered the collective, reduced the throttle, and started to descend about 100 ft per minute. During the descent, he observed that the engine rpm was slightly above 2,900 rpm. He reduced the throttle, and the rpm reduced slightly; however, it again increased to 2,900 rpm, and the manifold pressure was about 10 inches of mercury. When the helicopter was about 400 ft above ground level, the pilot heard the engine sound increase, and he observed that the engine rpm had increased to between about 3,300 and 3,500 rpm. The helicopter was unable to reach the runway, so the pilot continued to descend it toward a pasture, and it landed hard in the dirt.
A postaccident airframe and engine examination and subsequent engine run revealed no preimpact anomalies that would have precluded normal operation. The observed damage to the main rotor blades was consistent with blade coning, a condition indicative of low main rotor rpm. It is likely that the student pilot mismanaged the main rotor rpm during the descent, which resulted in a low rotor rpm and a high descent rate during landing.
Probable cause
The student pilot's mismanagement of the main rotor rpm, which resulted in low rotor rpm, a high descent rate, and a subsequent hard landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR17LA158
- Event ID
- 20170720X43914
- Case number
- WPR17LA158
- 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: 910e6b4e8cc2c274a7e6e4190edcabaeecca0b43bb8d0079c1c80ef749a38b92; retrieved 2026-09-16T05:34:10.591Z.