Boeing 747SR-146B SF JA8158
5 December 2004 · Anchorage, Alaska, United States · No injuries
Summary
On 5 December 2004 at about 18:00 local time, a Boeing 747SR-146B SF registered JA8158 was involved in an incident near Anchorage, Alaska, United States. 3 people were on board and nobody was injured. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.
The record
- Date
- at 18:00
- Classification
- Incident
- Location
- Anchorage, Alaska, United States
- Coordinates
- 61.1744, -149.9964
- Aircraft
- Boeing 747SR-146B SF
- Registration
- JA8158
- Category
- Airplane
- Engines
- 4
- Operator
- Not recorded
- Operating rule
- Part 129: Foreign
- Phase of flight
- Not recorded
- Route
- Anchorage → Tokyo-Narita
- Aircraft damage
- Minor
- Weather
- VMC
- Light
- Day
- NTSB number
- ANC05IA016
People
Nobody was injured.
| On board | Died | Serious | Minor | Uninjured |
|---|---|---|---|---|
| 3 | 0 | 0 | 0 | 3 |
Probable cause
The fatigue and subsequent fracture of a portion of the airplane's pressure bulkhead, which resulted in a rapid decompression during cruise flight.
Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.
Read the full NTSB narrative
The 14 CFR Part 129 non-scheduled international cargo flight had a rapid decompression at 30,000 feet msl, and returned to the takeoff airport. An examination revealed an elliptical tear in the right side of the pressure bulkhead web separating the electronics service bay from the nose wheel well. The tear extended about 12-inches along a horizontal rivet line, with both ends of the torn skin turned downward approximately 80-90 degrees. The damaged area (STA 260-280, WL 160-170) was excised from the structure, and an examination of the fracture mechanism was conducted. The fracture examination disclosed that the web fracture was initiated by fatigue from multiple origins on the outboard web surface within the pressure vessel. Ten separate fatigue cracks propagated through the full web thickness before the onset of rapid ductile tearing. Each fatigue crack formed adjacent to a fastener hole common with the WL 170 beam, and was in line with the edge of the bonded strip doublers on the inboard surface (wheel well side). The web material met all the engineering specifications. At the time of the incident, the airplane had logged 58,185 flight hours, and 27,243 cycles/landings. Inspection criteria for the affected area is contained in a manufacturer's Service Bulletin and their Alert Revisions 1 thru 4. Following the examination of the incident airplane, Alert Revision 4 was amended to specify more frequent inspections of the affected area.
Quoted verbatim from the NTSB record.
Other Boeing 747 accidents
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 21 Oct 2004 | Boeing 747-132 | Lake Michigan, United States | - | No injuries | - |
| 12 Dec 2004 | Boeing 747 | London, United Kingdom | Atlas Air Inc | No injuries | - |
| 14 Dec 2004 | Boeing 747-200 | Incheon, Republic Of Korea | Air Atlanta Icelandic | No injuries | - |
| 29 Dec 2004 | Boeing 747-123 | Anchorage, Alaska, United States | - | No injuries | - |
| 14 Oct 2004 | Boeing 747-244BC | Halifax, Canada | MK Airlines | Fatal | 7 |
| 31 Aug 2004 | Boeing 747-400 | Hanamaki, Japan | Japan Airlines Co Ltd | Serious injuries | - |
Other accidents in this area
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 6 Sep 2004 | Piper PA-22-160 | Kenai, Alaska, United States | - | No injuries | - |
| 3 Sep 2004 | Piper PA-18-150 | Anchorage, Alaska, United States | Eric A. Swenson | No injuries | - |
| 13 Jun 2004 | Cessna 185 | Skwentna, Alaska, United States | - | No injuries | - |
| 26 Jun 2004 | Beechcraft 36 | Talkeetna, Alaska, United States | John Collins | Fatal | 1 |
| 25 Jun 2004 | Christen HUSKY A-1 | Bethel, Alaska, United States | - | No injuries | - |
| 24 Jun 2004 | Rufli | Fairbanks, Alaska, United States | - | No injuries | - |