NYC97GA148 · Schweizer 269C
Baltimore Police Department Schweizer 269C · Accident: total loss of engine power (mechanical failure) while maneuvering
From Martin State Airport (MTN) to an unrecorded destination
Event
- NTSB case
- NYC97GA148
- 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
- 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
Schweizer 269C
- Aircraft type
- Schweizer 269
- Category
- Helicopter
- 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
- N6129Q
- Operator
- Baltimore Police Department
- Onboard fatalities
- Unknown
- Route
- From Martin State Airport (MTN), MDTo not recorded
- 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
- Maneuvering
- 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
- Destroyed
Cause areas
- Company maintenance personnel › Condition(s)/step(s) in error
- Company maintenance personnel › Maintenance, overhaul, major, not complied with
- Engine assembly, connecting rod › Fatigue
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The police pilot was flying the helicopter in a right-hand orbit approximately 500 feet. The pilot heard a loud 'clunk' and experienced an immediate loss of engine power. He entered an autorotation over an urban area, and the helicopter struck a tree and collided with terrain during the descent. Examination of the wreckage revealed the #4 connecting rod protruding from the engine case. The connecting rod bolts were stretched beyond the manufacturer's limits, and valve tappets with incorrect part numbers were installed. The engine records revealed the engine had been overhauled by T.W.Smith Engine Company Inc. approximately 500 flight hours prior to the accident flight. The overhaul records reflected maintenance and inspections performed on components not installed on the accident engine and on parts designated to be discarded and replaced. Examination of the fractured #4 connecting rod revealed '...crack arrest positions and ratchet marks, indicative of fatigue crack progression...' and galling spots on the fatigue origin areas.
Probable cause
A total loss of engine power which was a result of incomplete and improper engine overhaul by company maintenance personnel. A factor in the accident was the unsuitable forced landing area terrain.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC97GA148
- Event ID
- 20001208X08479
- Case number
- NYC97GA148
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1997-07-18.
- API snapshot SHA-256: 0fcd82282c74f80a80c443d1013800d3971fd1d4a67ded28d0ee4fa76e3fe9bf; retrieved 2026-09-21T11:58:22.343Z.