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ERA11LA484 · North American TB-25N

4 Sept 2011 · Georgetown, DE, United States

Rag Wings & Radials Aircraft Leasing North American TB-25N · Accident: landing gear collapse

From Patuxent River Naval Air Station (Trapnell Field) (NHK) to Delaware Coastal Airport (GED)

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Event

NTSB case
ERA11LA484
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

North American TB-25N

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
N9079Z
Onboard fatalities
Unknown
Route
From Patuxent River Naval Air Station (Trapnell Field) (NHK), Patuxent River, MDTo Delaware Coastal Airport (GED), Georgetown, DE
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 · landing roll
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
Landing gear collapse
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

  • Aircraft › Aircraft systems
  • Personnel issues › Task performance

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

According to both pilots, they landed the airplane and felt the right wing drop during the landing roll. They attempted to maintain directional control, but the right wing dropped further and the airplane veered off of the right side of the runway. During a subsequent examination of the wreckage, the right main landing gear shock strut drag arm was found broken. An examination of the broken drag arm revealed that it fractured in the I-beam at the blend radius of an orthogonal arm due to bending fatigue. Given the extent of fatigue crack propagation in the flange of the I-beam, it is likely that the fracture occurred due to high-cycle, low-stress fatigue. Since the depth of the fatigue crack was significant relative to the I-beam flange thickness, the fatigue crack probably developed and propagated over a long time under numerous low-stress cycles. The most recent inspection of the main landing gear was on July 7, 2011, which was in accordance with a conditional inspection. The inspection required a mechanic to verify the condition and security of the main landing gear. It is most likely that the fatigue crack would have been detectable at the time of that inspection.

Probable cause

Maintenance personnel's inadequate examination of the main landing gear during the airplane’s most recent conditional inspection, which resulted in the fatigue failure of the right main landing gear shock strut drag arm during the landing roll.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record ERA11LA484
Event ID
20110907X43224
Case number
ERA11LA484
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. 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: 8fcef002c5fe3a2eeb5fade236bd5fa2cba73264cf94cbfa896c57704e7ff4a0; retrieved 2026-09-15T16:42:52.376Z.