Status: | Accident investigation report completed and information captured |
Date: | Tuesday 11 August 2009 |
Time: | 11:14 |
Type: | de Havilland Canada DHC-6 Twin Otter 300 |
Operator: | Airlines PNG |
Registration: | P2-MCB |
MSN: | 441 |
First flight: | 1975 |
Total airframe hrs: | 46700 |
Engines: | 2 Pratt & Whitney Canada PT6A-27 |
Crew: | Fatalities: 2 / Occupants: 2 |
Passengers: | Fatalities: 11 / Occupants: 11 |
Total: | Fatalities: 13 / Occupants: 13 |
Aircraft damage: | Destroyed |
Aircraft fate: | Written off (damaged beyond repair) |
Location: | 11 km (6.9 mls) SSE of Kokoda Airport (KKD) ( Papua New Guinea)
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Crash site elevation: | 1760 m (5774 feet) amsl |
Phase: | En route (ENR) |
Nature: | Domestic Scheduled Passenger |
Departure airport: | Port Moresby-Jackson Field (POM/AYPY), Papua New Guinea |
Destination airport: | Kokoda Airport (KKD), Papua New Guinea |
Flightnumber: | 4684 |
Narrative:An Airlines PNG DHC-6 Twin Otter passenger plane was destroyed when it flew into a mountainside near Kokoda Airport (KKD), killing all 13 on board. Flight CG 4684 departed Port Moresby-Jackson Field (POM) at 10:53. The Area Weather Forecast (ARFOR) for the intended flight indicated forecasts of isolated showers and thunderstorms with areas of rain. Significant cloud layers at estimated base levels of 800ft with tops of 18,000ft above Mean Sea Level (MSL). Isolated Cumulo Nimbus (CB) or thunderstorm clouds was also forecasted reaching to tops of 45000 ft. Freezing levels was estimated at 15,500 ft above MSL with moderate to severe turbulence within the vicinity of the CB and cumuliform clouds.
At 11:10, the flight crew of P2-MCB reported leaving 9,000 ft on descent to Kokoda via the Kokoda Gap, which is approximately 12 NM (22 km) south-east of the Kokoda airstrip. This was the last radio contact with the flight.
The airplane flew into the side of a tree covered mountain at an altitude of 5774 feet (1760 metres).
The Kokoda Airport is located in a valley at an elevation of 1273 feet, surrounded by mountains in the North and South, some with an elevation of 8500 feet.
The airfield has a single runway, 17/35. It has a 2,2% down slope with landings restricted to runway 17.
Probable Cause:
CONTRIBUTING SAFETY FACTORS:
* Visual flight in the Kokoda Gap was made difficult by the extensive cloud coverage in the area.
* The crew attempted to continue the descent visually within the Kokoda Gap despite the weather conditions not being conducive to visual flight.
* It was probable that while manoeuvring at low level near the junction of the Kokoda Gap and Kokoda Valley, the aircraft entered instrument meteorological conditions.
* The aircraft collided with terrain in controlled flight.
OTHER SAFETY FACTORS:
* The copilot was assessed during normal proficiency checks for instrument approach procedures but was not qualified for flight in instrument meteorological conditions.
* The operator did not have a published emergency recovery procedure for application in the case of inadvertent flight into instrument meteorological conditions. [Minor safety issue]
* The Civil Aviation Safety Authority Papua New Guinea surveillance of the operator did not identify the operations by the operator in contravention of Rule 91.112.
* The lack of a reliable mandatory occurrence reporting arrangement minimised the likelihood of an informed response to Papua New Guinea-specific safety risks. [Minor safety issue]
* There was no qualified Director (or similar) of Aviation Medicine in Papua New Guinea (PNG). [Minor safety issue]
* The lack of both flight data and cockpit voice recorders adversely affected a full understanding of the accident by the investigation. [Minor safety issue]
OTHER KEY FINDINGS:
* The investigation was unable to discount the possible incapacitation of the copilot as a factor in the accident.
* Although not required by the aviation rules at the time of the accident, the adoption of threat and error management training for flight crews, and of the methodology by operators would provide a tool to identify and mitigate operational risk as follows:
- by flight crews, when flight planning and during flight; and
- by operators, when developing their operational procedures.
Accident investigation:
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Investigating agency: | AIC PNG |
Status: | Investigation completed |
Duration: | 1 year and 8 months | Accident number: | AS 09 1005 | Download report: | Final report
|
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Classification:
Controlled Flight Into Terrain (CFIT) - Mountain
Sources:
»
SKYbrary » Kokoda Track charter plane missing: 9 Australians on board (SMH, 11-8-2009)
» Airlines of PNG Twin Otter disappears in Papua New Guinea (Flightglobal, 11-8-2009)
Photos
accident date:
11-08-2009type: de Havilland Canada DHC-6 Twin Otter 300
registration: C-GNHB
accident date:
11-08-2009type: de Havilland Canada DHC-6 Twin Otter 300
registration: C-GNHB
Aircraft history
19 DEC 1974 |
C-GNHB |
On Air, operating for NorOntair |
registered
|
03 JAN 1984 |
C-GNHB |
Bearskin Airlines, operating for NorOntair |
On Air taken over by Bearskin
|
22 MAY 1986 |
C-GNHB |
Dale-Air, operating for NorOntair |
registered
|
27 MAY 1992 |
C-GNHB |
Bearskin Airlines, operating for NorOntair |
registered
|
03 SEP 1993 |
C-GNHB |
Dale-Air, operating for NorOntair |
registered
|
29 JAN 1997 |
P2-MCB |
Milne Bay Air |
registered
|
2001 |
P2-MCB |
Airlines PNG |
airline renamed
|
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does
not display the exact flight path.
Distance from Port Moresby-Jackson Field to Kokoda Airport as the crow flies is 83 km (52 miles).
Accident location: Approximate; accuracy within a few kilometers.
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.