FTW00LA242 · Mitsubishi MU-2B-35
Mitsubishi MU-2B-35 · Accident: propeller failure/malfunction en route
From Dallas Love Field (DAL) to William P. Hobby Airport (HOU)
Event
- NTSB case
- FTW00LA242
- 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
- Charter & commuter
- 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
Mitsubishi MU-2B-35
- Aircraft type
- Mitsubishi MU-2
- 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
- N770MA
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Dallas Love Field (DAL), Dallas, TXTo William P. Hobby Airport (HOU), Houston, TX
- 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 135: Air Taxi & Commuter
- 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 · 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
- Propeller failure/malfunction
- 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
- Propeller system/accessories, blade › Corroded
- Propeller system/accessories, blade › Fatigue
- Propeller system/accessories, blade › Separation
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The twin-engine airplane was in cruise flight at 11,000 feet msl, when the pilot heard a loud bang and felt the airplane vibrate. The pilot shut down the right engine, feathered the propeller, and landed the airplane at an alternate airport. Examination of the right propeller revealed that one of its propeller blades separated approximately 8.5 inches from the hub. This blade was manufactured from 7076 aluminum alloy, which is referred to as a 'hard alloy.' Examination of the propeller blade's fracture surface revealed that it failed as a result of fatigue cracking, which originated from an area of intergranular corrosion. The propeller was overhauled 222 hours prior to the accident. According to the overhaul facility, they used a process of Alodining the blades for corrosion control, which is an approved method. According to the propeller manufacturer, the preferred method of corrosion control is anodizing due to its corrosion detection properties; however, it is a more expensive and time consuming corrosion control process. As a result of this accident, the propeller manufacturer issued a service bulletin indicating that 'hard alloy' blades should be removed from service due to their susceptibility to intergranular corrosion.
Probable cause
the in-flight separation of the propeller blade, which resulted from intergranular corrosion and fatigue cracking.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW00LA242
- Event ID
- 20001212X21737
- Case number
- FTW00LA242
- 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: ca5965ea40ffc0a9ba63bd09b288b5096797094c4b08c6d8c105cd6c70fda97e; retrieved 2026-09-18T16:27:57.282Z.