WPR11LA202 · Rans S-12 S
Rans S-12 S · Accident: aerodynamic stall/spin during landing
From The Ultralight Strip Ultralightport (4AZ8) to Chapman Ranch Airstrip (58AZ)
Event
- NTSB case
- WPR11LA202
- 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
Rans S-12 S
- Aircraft type
- Rans S-12
- Category
- Airplane
- 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
- N107JL
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From The Ultralight Strip Ultralightport (4AZ8), Avra Valley, AZTo Chapman Ranch Airstrip (58AZ), Young, AZ
- 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
- Landing
- 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
- Aerodynamic stall/spin
- 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 › Fluids/miscellaneous hardware
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
Before the flight, the sport pilot fueled the experimental, amateur-built, light-sport airplane and conducted a preflight inspection without the aid of a checklist. He and his passenger then departed for a destination about 110 miles away. About 14 minutes after takeoff, during the climb, the passenger smelled engine coolant, and the pilot observed excessively high engine oil and coolant temperature indications. He reduced engine rpm and decided to conduct a precautionary landing at a non-towered airport south of his current position. When the airplane was north of the runway threshold, he realized that he would not reach the runway and aimed instead for the airport ramp. He then realized he would not reach the ramp and intentionally allowed the airplane to stall onto the flat earthen floor of a water catchment basin. The pilot did not use available engine power during the descent to ensure a landing on an appropriate surface, even though the engine remained running until he shut it down after impact. Examination of the airplane revealed that the engine coolant had drained in flight due to an unsecured system cap. The pilot stated that he did not check the coolant system during his preflight inspection.
Probable cause
The pilot's failure to conduct an adequate preflight inspection, which resulted in a loss of engine coolant during climb due to an unsecured tank cap. Contributing to the accident was the pilot's failure to use available engine power to ensure a landing on an appropriate surface.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR11LA202
- Event ID
- 20110416X01319
- Case number
- WPR11LA202
- 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: 44326474c740d45e90b614df04196f753be8dc87e76eb8fd5d4feeab3ed5b411; retrieved 2026-09-15T16:04:07.055Z.