CHI91DER10 · Kolb Company TWINSTAR MK II TWINSTAR M
Kolb Company TWINSTAR MK II TWINSTAR M · Accident: airframe, component or system failure during initial climb
Event
- NTSB case
- CHI91DER10
- 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
- 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
Kolb Company TWINSTAR MK II TWINSTAR M
- Aircraft type
- Kolb TWINSTAR MK
- Category
- Ultralight
- 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
- N503BP
- Operator
- William T. Poage · private individual
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- 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
- Initial climb
- First occurrenceThe 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
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Flt control syst, elevator trim/tab control › Disconnected
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
WITNESSES REPORTED THEY WATCHED THE ULTRALIGHT TAKE OFF AND NOTED THE ELEVATOR OSCILLATING RAPIDLY, 'FLUTTERING.' THEY STATED THE AIRCRAFT CLIMBED TO ABOUT 200 FEET ABOVE THE GROUND (AGL), THEN THE PILOT BEGAN A TURN BACK TOWARD THE AIRPORT. ACCORDING TO ONE WITNESS: 'THE AIRPLANE STALLED, WENT INTO A SPIN AND CRASHED.' THE ULTRALIGHT IMPACTED TERRAIN IN A MARSHY AREA LESS THAN ONE MILE FROM THE DEPARTURE AIRPORT. POST ACCIDENT INVESTIGATION REVEALED THE TRIM TAB CONTROL CABLE HAD UNSPOOLED FROM THE TRIM TAB WHEEL.
Probable cause
THE DISCONNECTED ELEVATOR TRIM CABLE. RELATED FACTORS ARE THE INADEQUATE MAINTENANCE/INSTALLATION, AND THE PILOT'S INABILITY TO MAINTAIN AIRCRAFT CONTROL.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI91DER10
- Event ID
- 20001212X17204
- Case number
- CHI91DER10
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1991-06-30.
- API snapshot SHA-256: 0283eb1ab29dec6beac5f3fdb29a7c7e867a8e41b10ef2bc8f9165bd703062c6; retrieved 2026-09-21T15:24:40.054Z.