CHI07CA028 · Cessna 421C
Cessna 421C · Accident: main gear collapsed during landing
From Rocky Mountain Metropolitan Airport (BJC) to Quad City International Airport (MLI)
Event
- NTSB case
- CHI07CA028
- 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
Cessna 421C
- 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
- N471BW
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Rocky Mountain Metropolitan Airport (BJC), Denver, COTo Quad City International Airport (MLI), Moline, 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
- Landing · flare/touchdown
- 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
- Main gear collapsed
- 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
- Landing gear, main gear strut scissors › Separation
- Other maintenance personnel › Maintenance, installation, 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 right main landing gear collapsed during landing flare/touchdown. The pilot reported that the airplane initially touched down on the left main landing gear, followed by the nose and right main landing gears. The pilot stated that when the right main landing gear touched it "didn't feel right or usual." The pilot reported that he advanced engine power, and the airplane became airborne for about 50 feet. The pilot stated that the airplane "bounced onto runway" and the right propeller impacted the runway. The airplane became airborne again, and then "landed hard" for the final time. Inspection of the right main landing gear showed that the upper and lower torque links had separated at the common pivot-point, which allowed the lower strut to rotate within the upper strut. The two torque links are connected by a bolt, nut, bushing, and several washers. The washer that prevents the bolt head and pressed bushing from pulling through the common pivot-point was not installed. The as-installed stack-up remained together, and was attached to the upper torque link. The pressed bushing from the lower torque link was found with the as-installed stack-up. The torque links for the left main landing gear were found correctly assembled.
Probable cause
The incorrect installation of the torque link scissor assembly by maintenance personnel, which resulted in the collapse of the right main landing gear during landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI07CA028
- Event ID
- 20070109X00026
- Case number
- CHI07CA028
- 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: e4531c22f0387c1af05c2ee21f332accc1142fb179779bf2ee15ef5c6261ea53; retrieved 2026-09-22T04:12:17.799Z.