Hughes 369D N1096L
8 December 1998 · Taholah, Washington, United States · Minor injuries
Summary
On 8 December 1998 at about 19:45 local time, a Hughes 369D registered N1096L was involved in an accident near Taholah, Washington, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.
The record
- Date
- at 19:45
- Classification
- Accident
- Location
- Taholah, Washington, United States
- Coordinates
- 47.3093, -124.2207
- Aircraft
- Hughes 369D
- Registration
- N1096L
- Category
- Helicopter
- Engines
- 1
- Operator
- Not recorded
- Operating rule
- Part 133: Rotorcraft Ext. Load
- Purpose of flight
- Other Work Use
- Phase of flight
- Not recorded
- Aircraft damage
- Substantial
- Weather
- VMC
- Light
- Day
- NTSB number
- SEA99FA018
People
1 person had minor injuries.
| On board | Died | Serious | Minor | Uninjured |
|---|---|---|---|---|
| 1 | 0 | 0 | 1 | 0 |
Probable cause
Turbine wheel failure as the result of a low-cycle fatigue crack that initiated in a beyond-limits grinding gouge. Factors include improper maintenance by unknown parties and tree stumps that prohibited a successful emergency landing.
Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.
Read the full NTSB narrative
While conducting external load operations the helicopter sustained substantial damaged after a loss of engine power, autorotation, and forced landing. A witness reported hearing a loud bang, followed by the engine spooling down. The witness also reported seeing smoke coming from the engine as the helicopter descended through the trees, landing hard on a tree stump under the pilot's seat area. Postaccident inspection of the turbine engine revealed excessive blending in the web of the first stage turbine wheel. Within the blending, a notch exhibited a radius sharper than allowed by blend limits, which the manufacturer' metallurgists believed to have been created by a hand-held grinder. It could not be determined whether the manufacturer of the turbine wheel or an overhaul facility made the subject grinding marks.
Quoted verbatim from the NTSB record.
Other Hughes 369 accidents
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 22 Mar 1998 | Hughes 369E | Seattle, Washington, United States | - | Minor injuries | - |
| 24 Jan 1998 | Hughes 369D | Pacific Ocean | - | Fatal | 1 |
| 16 Jun 1998 | Hughes 369HS | Pacific Ocean | - | Fatal | 2 |
| 27 Sep 1998 | Hughes 369D | Homer, Alaska, United States | Bureau of Land Management | Serious injuries | - |
| 9 Jul 1998 | Hughes 369D | Raymond, Washington, United States | - | Fatal | - |
| 7 Jun 1999 | Hughes 369HS | Pacific Ocean | - | Minor injuries | - |
Other accidents in this area
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 31 Mar 1998 | Cessna P210N | Royal City, Washington, United States | - | Fatal | 3 |
| 4 Jun 1998 | Cessna 172N | Prindle, Washington, United States | - | Fatal | 3 |
| 9 Apr 1998 | Cessna 150L | Seattle, Washington, United States | - | Minor injuries | - |
| 30 Jul 1998 | Embraer EMB-135 | Moses Lake, Washington, United States | - | No injuries | - |
| 19 Jul 1998 | Cessna 172P | Seattle, Washington, United States | Wings Aloft Inc. | No injuries | - |
| 24 Jul 1998 | Pilgrim STEEN SKYBOLT | Curtis, Washington, United States | - | Minor injuries | - |