CEN16FA331 · Stemme Gmbh & Co S10 VT
Stemme Gmbh & Co S10 VT · Accident en route
From Telluride Regional Airport (TEX) to Telluride Regional Airport (TEX)
Event
- NTSB case
- CEN16FA331
- 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
- 2 · 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
Stemme Gmbh & Co S10 VT
- Aircraft type
- Stemme S10
- Category
- Glider
- 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
- N5021
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Telluride Regional Airport (TEX), Telluride, COTo Telluride Regional Airport (TEX), Telluride, CO
- Aircraft age
- About 19 years (built 1997)
- 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
- 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
- Miscellaneous/other
- 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 pilot was conducting a local sightseeing flight at the time of the accident. A witness reported seeing the powered glider climbing out after takeoff and the engine "sounded perfect." He subsequently heard the sound of a "strained engine" similar to a propeller-driven airplane maneuvering during aerobatic flight. Shortly afterward, the sound of the engine stopped. A second witness observed the powered glider fly by with the engine running. It subsequently went out of sight below the tree line. Shortly afterward, he heard a loud noise that he initially attributed to work going on in the area. However, with thoughts of the low flying glider, he decided to drive to a nearby ridge where he observed the accident site.
A postaccident examination and engine test run did not reveal any anomalies consistent with a preimpact failure or malfunction.
Witness statements and satellite imagery indicated that building cumuliform clouds were present near the accident site. Weather radar data depicted a rain shower over the site about the time of the accident that appeared to be dissipating. With dissipating rain shower activity, the glider was in a favorable area for the existence of downdrafts. It is likely that the pilot encountered a downdraft that exceeded the maximum climb performance of the powered glider.
Probable cause
The pilot's encounter with a downdraft that exceeded the climb performance of the powered glider and resulted in his inability to maintain clearance from the trees. Contributing to the accident was the pilot's decision to fly near building clouds and rain shower activity.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN16FA331
- Event ID
- 20160824X81825
- Case number
- CEN16FA331
- 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: bca830d90a6d6f71e067e7e7a84c7b903a4301dbe4ac99981cb80ff8ebdbf54d; retrieved 2026-09-14T21:58:53.384Z.