CEN24FA228 · Cessna 421 C
Cessna 421 C · Accident: loss of control in flight on approach
From Vance Brand Airport (KLMO) to Steamboat Springs Bob Adams Field (KSBS)
Event
- NTSB case
- CEN24FA228
- 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
- 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
Cessna 421 C
- Aircraft type
- Cessna 421
- 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
- N245T
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Vance Brand Airport (KLMO), Longmont, COTo Steamboat Springs Bob Adams Field (KSBS), Steamboat Spring, CO
- Aircraft age
- About 44 years (built 1980)
- 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
- Approach · VFR pattern base
- 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
- Loss of control in flight
- 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
- Aircraft › Aircraft oper/perf/capability
- Personnel issues › Psychological
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While enroute to the destination airport, the pilot reported a “cylinder temperature issue” to air traffic control (ATC) and the pilot diverted to another airport for a visual approach. The pilot overflew the airport and requested vectors for another visual approach. He then requested vectors to divert to an airport to the east before he informed air traffic control that the left engine lost power, and he received vectors back to the airport for a visual approach. The pilot maneuvered the airplane to land on runway 14, but for an unknown reason he decided to land on runway 32 instead. A pilot-rated witness reported that he observed the airplane while it was on the base to final turn for runway 32. He reported that the airplane’s wings leveled momentarily before it made a 60° left-bank turn and then entered a stall/spin in a counterclockwise rotation. The airplane impacted a trailer park about 0.38 miles from the approach end of runway 32. A postimpact fire ensued and destroyed the airplane. Examination of the airframe, flight controls, and the right engine did not detect any preimpact anomalies that would have precluded normal operation. Examination of the left engine found that the starter adapter spline was worn, with broken teeth on its crankshaft gear. The crankshaft gear remained properly timed with the crankshaft cluster gear, the investigation could not determine if the idler gear, which drives the magnetos, slipped timing. Mistiming of the magnetos could result in abnormal cylinder head temperature(s). In addition, there was improper hardware securing the cylinder No. 6 intake valve, which might have altered performance of that valve. Due to thermal damage, testing of the ignition and fuel systems could not be accomplished. Evidence of detonation was observed on the left engine’s piston heads. The installed engine data monitor was destroyed by the postimpact fire and did not provide further details as to the operational condition of the engine before the accident. Inspection of the starter adapter assembly is required annually by airworthiness directive and was accomplished on the most recent annual inspection. The airplane had flown about 5.5 hours since the inspection.
Probable cause
The pilot’s failure to maintain sufficient airspeed following a loss of engine power, which resulted in an inadvertent aerodynamic stall/spin at low altitude.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN24FA228
- Event ID
- 20240618194487
- Case number
- CEN24FA228
- 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, cause areas. 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: 4eefdb87367b77891e8c3caf657975372d2a49033e55d0a02ac91c4d69f8d8dc; retrieved 2026-09-15T08:19:00.369Z.