ATL05FA032 · Cessna 421B
Cessna 421B · Accident: partial loss of engine power (mechanical failure) during initial climb
From 3M3 · Collegedale, TN to McGhee Tyson Airport (TYS)
Event
- NTSB case
- ATL05FA032
- 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
- 5 · 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
Cessna 421B
- 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
- N421SD
- Onboard fatalities
- Unknown
- Route
- From 3M3 · Collegedale, TNTo McGhee Tyson Airport (TYS), Knoxville, TN
- 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
- 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
- Destroyed
Cause areas
- Pilot in command › Emergency procedure, improper
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The airline transport pilot (ATP) stated the airplane was between 200 to 300 feet on initial takeoff climb when the right engine lost power and the airplane yawed to the right. The pilot lowered the nose of the airplane to gain airspeed, pulled the right power lever rearward and nothing happened. The pilot did not feather the right propeller and started moving switches in the vicinity of the boost pump switches. The ATP passenger stated, he did not think the left engine was producing full power. He scanned the instruments with his eyes looking at the manifold pressure gauges. "One needle was at zero and the other was at 25-inches. The manifold pressure should have been 39-inches of manifold pressure. The ATP passenger observed trees to their front and thought the pilot was trying to make a forced landing in an open field to their left. The ATP passenger realized the airplane was going to collide with the trees. Just before the airplane collided with the trees, the pilot feathered the right engine. The ATP passenger observed the right propeller going into the feather position, and the propeller came to a complete stop. Examination of the right engine revealed no anomalies. Examination of the left engine revealed the starter adapter gear teeth had failed due to overload.
Probable cause
The pilot's improper identification of a partial loss of engine power on initial takeoff climb resulting in a collision with trees and the ground. A factor was a partial failure of the left engine starter adapter due to overload.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ATL05FA032
- Event ID
- 20041207X01930
- Case number
- ATL05FA032
- 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: 77d37be65ce09dfe0be2e2520c4007ee67e64a6520844feca00b62da20c64b0e; retrieved 2026-09-20T18:11:21.733Z.