DEN05TA072 · Bell OH-58C
Bell OH-58C · Accident: airframe, component or system failure en route
From City of Colorado Springs Municipal Airport (COS) to an unrecorded destination
Event
- NTSB case
- DEN05TA072
- 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
Bell OH-58C
- Aircraft type
- Bell OH-58
- 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
- N198PD
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From City of Colorado Springs Municipal Airport (COS), Colorado Sprngs, COTo 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
- 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
- Engine instruments, tachometer › Failure
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
According to the pilot, he was orbiting over a campus when the "engine out light illuminated in the cockpit," followed by an "audible engine out alarm" and the "N1 gauge dropped." The pilot elected to perform a precautionary landing to a field. The pilot stated that the terrain sloped uphill and the helicopter stopped "abruptly" and rock back and forth. A postaccident examination revealed that the N1 Tachometer Generator had failed. Further examination revealed that the N1 tachometer generator wire was not connected to the cannon plug and frayed. Examination of the helicopter's remaining systems revealed no anomalies.
Probable cause
the failure of the N1 tachometer generator which resulted in a precautionary landing. Contributing factors include the frayed wire and the unsuitable terrain for a precautionary landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN05TA072
- Event ID
- 20050511X00591
- Case number
- DEN05TA072
- 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 2005-04-08.
- API snapshot SHA-256: c28a14d8b5646f84d93724e7a91e26bd2d3a96f3028ed24dd829e708df725d06; retrieved 2026-09-22T06:06:33.135Z.