CHI99IA096 · Cessna T210R
Cessna T210R · Incident: total loss of engine power (mechanical failure) during an emergency descent
From Abraham Lincoln Capital Airport (SPI) to CGX · Chicago, IL
Event
- NTSB case
- CHI99IA096
- 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
- Incident
- 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
Cessna T210R
- Aircraft type
- Cessna 210
- 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
- N7687U
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Abraham Lincoln Capital Airport (SPI), Springfield, ILTo CGX · Chicago, IL
- 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
- Emergency descent
- 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
- Total 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
- Minor
Cause areas
- Other maintenance personnel › Maintenance, installation, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot of the incident airplane said that in-flight at 1800 feet above mean sea level, the engine seized, the propeller bolts sheared, the propeller fell to the ground, and that he landed the airplane without any damage to the airplane. During an inspection of the engine, a 'B' nut on the oil pressure line to the turbocharger was found loose. The cylinders in the area of the 'B' nut were found with a dark, oily substance coating them. The turbocharger and its housing were found with a dark, charred, oily substance on it. Number one, four, five, and six crankshaft journals revealed distress. The number one crankshaft journal was found blue. The number four connecting rod was found broken and colored blue. The number four cylinder head was found separated from its base. The propeller hub and engine crankshaft flange mating surfaces were found with areas of distress. Three of the studs that held the propeller to the crankshaft flange were found with their fracture initiating on opposite sides of those studs. A top overhaul was performed 85 tachometer hours prior to the accident.
Probable cause
the improper installation of the pressure oil line 'B' nut by maintenance personnel. Contributing to the incident were the loose pressure oil line 'B' nut and separation of the propeller from the aircraft.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI99IA096
- Event ID
- 20001205X00127
- Case number
- CHI99IA096
- 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: 304550e93af2d3647eac94b5ba6cb3b92af28110a2234c68b5a5f112742ebb53; retrieved 2026-09-22T15:50:32.172Z.