CHI07LA273 · Terpstra Exec 162F
Terpstra Exec 162F · Accident: airframe, component or system failure en route
From Arens Field (RWN) to Unknown
Event
- NTSB case
- CHI07LA273
- 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
- 1 · 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
Terpstra Exec 162F
- Aircraft type
- Terpstra EXEC 162
- 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
- N428JT
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Arens Field (RWN), Winamac, INTo Unknown
- 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
- 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
- Substantial
Cause areas
- Horizontal stabilizer attachment › Fatigue
- Horizontal stabilizer attachment › Separation
- Owner/builder › Installation, inadequate
- Owner/pilot mechanic › Aircraft control, not possible
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The experimental amateur-built rotorcraft impacted terrain during cruise flight following the in-flight separation of the vertical stabilizer, which resulted in damage to the tail rotor. The rotorcraft was registered to and built by the pilot. The pilot did not hold a rotorcraft rating and received a 90-day solo endorsement to pilot the rotorcraft approximately 10 months before the accident. Examination of the vertical stabilizer revealed fatigue fracture of the vertical stabilizer bracket originating from hole burrs. The airplane construction manual states, "It is good practice to remove all sharp edges when working with sheet metal. Various types of deburring tools are available, or use a file or sandpaper."
Probable cause
The inadequate installation of the horizontal stabilizer bracket by the pilot, the fatigue fracture seperation of vertical stabilizer bracket during cruise flight, and the aircraft control not possible by the pilot.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI07LA273
- Event ID
- 20070820X01211
- Case number
- CHI07LA273
- 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: investigation status, coordinates. 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: 6ed829f51be81c37947774dfa99f69eb006022ade791102bcd26f0f18f51bc34; retrieved 2026-09-20T16:21:03.035Z.