# NTSB Accident NYC91LA104
> **PIPER J-4A** · 1991-04-07 · MAHOPAC, NY, USA · MINR
## Event
- **NTSB number:** NYC91LA104
- **Event ID:** 20001212X16861
- **Type:** Accident
- **Date:** 1991-04-07
- **Location:** MAHOPAC, NY, USA
- **Coordinates:** 41.359058, -73.739799
## Injuries
- **Highest injury:** MINR
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 2
- **Uninjured:** 0
- **Total aboard:** 2
## Aircraft
- **Make:** PIPER
- **Model:** J-4A
- **Registration:** N23179
- **FAR Part:** 091
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

THE ERRATIC PERFORMANCE OF THE LEFT MAGNETO RESULTING IN INADEQUATE CLIMB CAPABILITIES AND IN FLIGHT COLLISION WITH TERRAIN.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=NYC91LA104) · AI Analytics · CC0 1.0*