DEN91LA053 · Rockwell 112B
Rockwell 112B · Accident: partial loss of engine power (mechanical failure) en route
From Rocky Mountain Metropolitan Airport (BJC) to Steamboat Springs Bob Adams Field (SBS)
Event
- NTSB case
- DEN91LA053
- 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
Rockwell 112B
- Aircraft type
- Rockwell 112
- 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
- N1241J
- Operator
- Berger, Henry M. & June H.
- Onboard fatalities
- Unknown
- Route
- From Rocky Mountain Metropolitan Airport (BJC), Broomfield, COTo Steamboat Springs Bob Adams Field (SBS), Steamboat Springs, CO
- 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 · climb to 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
- Partial loss of engine power (mechanical 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
- Ignition system, ignition harness › Deteriorated
- Ignition system, ignition lead › Arcing
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
AS THE AIRPLANE ENTERED A MOUNTAIN PASS, THE PILOT NOTICED DECREASING ENGINE MANIFOLD PRESSURE. UNABLE TO CLEAR HIGHER TERRAIN, HE MADE A FORCED LANDING IN DEEP SNOW. POST-ACCIDENT EXAMINATION REVEALED THE RIGHT IGNITION HARNESS WAS DETERIORATED AND THE IGNITION LEADS HAD ARCED. THE LEFT IGNITION HARNESS (SLICK 1200 SERIES) HAD BEEN ALTERED WITH THE USE OF UNAPPROVED BENDIX 'PANCAKE' GROMMETS. THE AIRPLANE HAD FLOWN 129 HRS SINCE THE LAST ANNUAL INSPECTION. CONDITIONS PREVENTED RECOVERY OF THE WRECKAGE UNTIL 6/27/91. TOTAL TIME ON THE ENGINE WAS 1,714 HRS. RECOMMENDED OVERHAUL INTERVAL WAS 1,800 HRS.
Probable cause
DETERIORATED IGNITION HARNESS AND IGNITION LEAD ARCING. FACTORS WERE THE HIGH DENSITY ALTITUDE AND LACK OF SUITABLE TERRAIN FOR THE FORCED LANDING.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN91LA053
- Event ID
- 20001212X16590
- Case number
- DEN91LA053
- 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. 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: 664aa641bd5d878d0b5ffbe520914047d6af1c6ee45e8b29cfec21febaf0eaa8; retrieved 2026-09-21T15:30:15.989Z.