WPR10LA138 · Robinson Helicopter R22 BETA
Robinson Helicopter R22 BETA · Accident: loss of control in flight en route
From Fresno Yosemite International Airport (FAT) to Meadows Field (BFL)
Narrative check · The NTSB narrative appears to contradict this record's location. Values are shown as recorded, not corrected; compare with the narrative.
Event
- NTSB case
- WPR10LA138
- 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
Robinson Helicopter R22 BETA
- Aircraft type
- Robinson R22
- 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
- N313DA
- Operator
- Richard Coe
- Onboard fatalities
- Unknown
- Route
- From Fresno Yosemite International Airport (FAT), Fresno, CATo Meadows Field (BFL), Bakersfield, 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
- En route · cruise
- 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
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The helicopter pilot was on the first leg of a ferry flight. The helicopter was 3.2 hours out of its 2,200-hour overhaul. The pilot reported that he was in straight-and-level flight and he initiated a right turn. The helicopter immediately rolled to the right and entered a low-G condition. The pilot responded appropriately and righted the helicopter. He then conducted a power-on landing. As the main rotor system came to a stop, one of the blades impacted the tailboom. Post landing examination of the rotorhead revealed that the pitch change link on the red main rotor blade had fractured, the spindle tusk had sheared off, and damage to both elastomeric teeter stops was evident. Metallurgical examination of the spindle tusk determined that it failed in a downward direction relative to the rotor blade due to shear overstress. Examination of the pitch change link determined that it failed due to overstress characterized by reverse bending numerous times to failure. Witness marks on the pitch link and pitch change arm indicated that the angle of the blade at the time of the pitch link failure was 45-degrees downward, an angle that could be achieved if the spindle tusk had already been fractured. According to Robinson Helicopter Company, this angle could also be obtained during extreme teeter of the hub/blade during a mast bumping event. A Robinson Helicopter Company publication notes, "Pushing the cyclic forward following a pull-up or rapid climb, or even from level flight, produces a low-G (weightless) flight condition. If the helicopter is still pitching forward when the pilot applies aft cyclic to reload the rotor, the rotor disk may tilt aft relative to the fuselage before it is reloaded. The main rotor torque reaction will then combine with tail rotor thrust to produce a powerful right rolling moment to the fuselage. With no lift from the rotor, there is no lateral control to stop the rapid right roll and mast bumping can occur."
Probable cause
The pilot inadvertently entered a low-G condition during cruise flight, which resulted in a momentary loss of control of the helicopter and mast bumping.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR10LA138
- Event ID
- 20100218X93903
- Case number
- WPR10LA138
- 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: 042b29c8e6bfefefc7fae480dce921a4efa6f3bbe8b5bee0775e3ee898c5acb9; retrieved 2026-09-15T13:41:26.916Z.