CEN26LA175 · Hiller UH-12E
Hiller UH-12E · Accident: system/component malfunction/failure (non-power) while maneuvering
Event
- NTSB case
- CEN26LA175
- 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
- Ongoing
- 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
Hiller UH-12E
- Aircraft type
- Hiller UH-12
- 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
- N22SP
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- Aircraft age
- About 67 years (built 1959)
- 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 137: Agricultural
- 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 · low-altitude flying
- 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
- System/component malfunction/failure (non-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
No findings designated as a cause are recorded in the NTSB data yet.
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
On April 30, 2026, about 1730 central daylight time, a Hiller UH-12E, N22SP, was substantially damaged when it was involved in an accident near Chickasha, Oklahoma. The pilot was not injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. The pilot reported that he had completed two aerial application flights earlier that day and performed preflight inspections before both. About 1700, he began spraying a field and during the flight, the main rotor “developed a vertical hop,” and he observed one of the control rotor blades separate from the helicopter. The helicopter violently shook, and he conducted a forced landing to a field. During the landing, the main rotor blades struck the tail boom, which severed the tail boom near the tail rotor. The responding FAA inspector and the pilot located the separated control rotor blade in the field about 100 yards from the accident site. A review of the FAA airworthiness directives (AD) indicated that AD 97-10-16 was applicable to the Hiller UH-12 helicopter. The AD required (in part) that the control rotor blade spar tube (or cuff) be inspected for corrosion or cracks, or elongation, corrosion, burrs, pitting or fretting of the bolt holes…during the annual inspection, not to exceed 100 hours and every 100-hours thereafter. The actions specified by the AD are intended to prevent separation of the control rotor blade assembly and subsequent loss of control of the helicopter. According to the helicopter maintenance records, an annual inspection was completed on February 20, 2026. During the inspection, the control rotor cuffs and trunnions were overhauled and reinstalled in accordance with the Hiller overhaul manual. The records show that AD 97-10-16 was complied with at this time. The separated control rotor was retained for further examination.
Verbatim NTSB factual narrative from the NTSB dataset
Sources
NTSB record CEN26LA175
- Event ID
- 20260505202933
- Case number
- CEN26LA175
- 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: 1ccd1317007cc01cadd2ec8c444936b5e131168a7ad2855382ca6839342fad8a; retrieved 2026-09-16T21:23:27.264Z.