De Havilland DHC-6 Twin Otter

Operator:

Registration:

9N-ABH

Flight Phase:

Flight Type:

Survivors:

Site:

Mountains

Schedule:

Kathmandu - Bhojpur

MSN:

376

YOM:

1973

Location:

Country:

Region:

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Circumstances:

While descending to Bhojpur in marginal weather conditions, the Twin Otter struck the slope of a mountain located few km from the airport. All three crew members and 12 passengers were killed while eight others were injured.

Probable cause:

It was determined that the crew initiated the descent prematurely, causing the aircraft to descend below the MDA.

Crash of a De Havilland DHC-6 Twin Otter 300 in Karege: 3 killed

Date & Time: Dec 20, 1984 at 1851 LT

Type of aircraft:

Operator:

Registration:

5H-MRD

Flight Phase:

Flight

Flight Type:

Training

Survivors:

Site:

Plain, Valley

Schedule:

Dar es Salaam - Dar es Salaam

MSN:

581

YOM:

1978

Location:

Country:

Region:

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Captain / Total flying hours:

5295

Captain / Total hours on type:

446.00

Copilot / Total flying hours:

296

Copilot / Total hours on type:

Circumstances:

The crew (one instructor and two pilots) departed Dar es Salaam Intl Airport on a local training flight. In the early evening, while returning to the airport, the twin engine airplane went out of control, entered a dive and crashed in a wooded area, bursting into flames. The wreckage was found near Karege, about 35 km northwest of Dar es Salaam Airport. The aircraft was totally destroyed and all three crew members were killed. The instructor totalized 5,295 flying hours with 446 on type. Both other pilots totalized 300 flying hours with 20 on type and 296 flying hours with 16 on type.

Probable cause:

The exact cause of the accident could not be determined with certainty. However, it was reported that the loss of control occurred when the power lever of the left engine was in idle position while the reverser on the left engine was activated at the same time. Thus, investigators does not rule out the assumption that the pilot attempted to commit suicide. Also, the assumption that the crew lost control of the airplane following a sudden and violent fire on the right engine was also not ruled out.

Crash of a De Havilland DHC-6 Twin Otter 300 in Bagua: 21 killed

Date & Time: Dec 19, 1984 at 1357 LT

Type of aircraft:

Charter/Taxi (Non Scheduled Revenue Flight)

Operator:

Registration:

FAP307

Flight Phase:

Takeoff (climb)

Flight Type:

Survivors:

Site:

Schedule:

Iquitos – Bagua – Piura

MSN:

317

YOM:

1971

Location:

Country:

Region:

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Circumstances:

After takeoff from Bagua-El Valor Airport, while climbing, the aircraft exploded and crashed. All 21 occupants were killed. The aircraft was completing a special flight from Iquitos to Piura with an intermediate stop in Bagua on behalf of PetroPeru.

Crash of a De Havilland DHC-6 Twin Otter 300 near Loja: 14 killed

Date & Time: Nov 20, 1984

Type of aircraft:

Operator:

Registration:

FAE446

Flight Phase:

Takeoff (climb)

Flight Type:

Survivors:

Site:

Mountains

Schedule:

Loja - Zumba

MSN:

446

YOM:

1975

Location:

Loja

Country:

Ecuador

Region:

South America

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Circumstances:

Few minutes after takeoff from Loja Airport, while climbing in poor weather conditions, the twin engine aircraft struck the slope of a mountain and crashed. All 14 occupants were killed. The aircraft had a dual registration: civil HC-BCG and military FAE446.

Crash of a De Havilland DHC-6 Twin Otter 100 in Goose Bay: 4 killed

Date & Time: Oct 11, 1984 at 1737 LT

Type of aircraft:

Operator:

Registration:

C-FAUS

Flight Phase:

Flight Type:

Ambulance

Survivors:

Site:

Schedule:

Saint Anthony - Goose Bay

MSN:

YOM:

1967

Location:

Goose Bay

Newfoundland & Labrador

Country:

Canada

Region:

North America

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Aircraft flight hours:

17585

Circumstances:

The Twin Otter departed Goose Bay on a medical evacuation flight to St. Anthony. The flight was uneventful and landed in St. Anthony at 15:24. At 16:02, the aircraft departed St. Anthony on a VFR flight back to Goose Bay. On board were the two pilots and the doctor and nurse. Approaching the Goose Bay Airport, weather became marginal, but the crew continued visual flight. The crew likely encountered near zero forward visibility in snow showers and fog; it is probable that they were able to maintain vertical contact with the ground and were confident they could continue flight with visual reference to the ground. The crew may not have been able to see terrain ahead and therefore may not have been able to determine if the aircraft would clear the hills, particularly, when steep hills were encountered. The plane struck a rock outcropping 100 feet below the summit of a 2,050-foot mountain. After bouncing twice, the Twin Otter had come to rest in a small, wooded gully, approximately 350 feet from the initial point of impact.

Probable cause:

It was determined that the flight was attempted in mountainous terrain in marginal weather conditions. The aircraft was flown at an altitude which did not provide terrain clearance, and the aircraft struck a mountain for undetermined reasons.

Crash of a De Havilland DHC-6 Twin Otter 200 in Fort Franklin: 7 killed

Date & Time: Oct 9, 1984 at 1730 LT

Type of aircraft:

Operator:

Nahanni Air Services

Registration:

C-FPPL

Flight Phase:

Flight Type:

Survivors:

Site:

Schedule:

Fort Norman - Fort Franklin

MSN:

115

YOM:

1968

Flight number:

NAS097

Location:

Fort Franklin

Northwest Territories

Country:

Canada

Region:

North America

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Aircraft flight hours:

23645

Circumstances:

The aircraft departed Fort Norman at 16:51 and arrived overhead Fort Franklin at approximately 17:15. Because Fort Franklin was shrouded in fog, a local resident contacted the pilot on a portable VHF transceiver and advised him that there was little or no visibility. The pilot replied that he did not think he would be able to land. The resident drove to the airstrip and contacted the pilot again when he heard the aircraft returning. He advised the pilot that visibility was 200-300 feet. The pilot then asked if this was the vertical or horizontal visibility. At that moment the Twin Otter struck a 200-foot-high telecommunications tower while in controlled level fight. Part of the right wing broke off and the aircraft slowly rolled over before striking the ground. The decision of the pilot to continue the approach in foggy weather were possibly influenced by the effects of stress and a greater than usual personal need to complete the flight. The stress was probably caused by the fact that the pilot had been involved in four accidents since March 1984. Although he was a very experienced pilot, his previous employer terminated his employment on 31 August 1984. In their opinion, his ability to make operational decisions was in question. The pilot was hired by Nahanni Air Services one month later.

Probable cause:

The following findings were reported:
- The weather at Fort Franklin was unsuitable for the flight,
- The flight was continued into weather below that which is required for VFR flight,
- An approach to the aerodrome was attempted using the radar altimeter to provide terrain clearance,
- The pilot descended to an altitude below the height of the telecommunications tower,
- A lack of official weather observations and of communications facilities at Fort Franklin deprived the pilot of reliable local weather information on which to base his decisions,
- There exists in the more remote areas of Canada a different attitude with regard to the assessment of risk in flight operations; it is likely that this attitude influenced the decisions and actions of the pilot,
- The operational decisions of the pilot may have been influenced by the effects of stress and a greater than usual personal need to complete the flight,
- Company management may have had a better appreciation of the risk potential associated with the recent events in the pilot's life, if they had more awareness of the effects of stress on performance.

Crash of a De Havilland DHC-6 Twin Otter 300 in Tau: 1 killed

Date & Time: Jul 21, 1984 at 1340 LT

Type of aircraft:

Operator:

Registration:

N43SP

Flight Phase:

Flight Type:

Survivors:

Site:

Samoa Islands (Western Samoa)

Schedule:

Pago Pago - Tau

MSN:

669

YOM:

1980

Flight number:

HK513

Location:

Tau

All Samoa Islands

Country:

Region:

Oceania

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Captain / Total flying hours:

5094

Captain / Total hours on type:

1020.00

Aircraft flight hours:

11281

Circumstances:

The aircraft crash landed after the pilot used flaps and power to semi control pitch after the elevator down control cable failed at about 300 feet agl on final approach. The left wing of the aircraft hit the terminal roof during the stall mush from 50 feet agl. The company is changing their aircraft control cables from steel to stainless steel to aid in the anti-corrosion and modifying their inspection period from 800 to 100 hours between inspections. The cable that separated failed from corrosion. No evidence of fatigue cracking or mechanical wear was found. Corrosion products were found within 2 inches of the serapation on both cable pieces.

Probable cause:

Occurrence #1: airframe/component/system failure/malfunction
Phase of operation: approach - vfr pattern - base leg/base to final
Findings
1. (c) flt control syst, elevator control - corroded
2. (c) flt control syst, elevator control - failure,total
----------
Occurrence #2: in flight collision with terrain/water
Phase of operation: descent - uncontrolled

Final Report:

Crash of a De Havilland DHC-6 Twin Otter 300 in Mokhotlong

Date & Time: Jul 13, 1984

Type of aircraft:

Operator:

Registration:

7P-LAA

Flight Phase:

Takeoff (climb)

Flight Type:

Survivors:

Site:

Schedule:

Mokhotlong - Maseru

MSN:

622

YOM:

1979

Location:

Mokhotlong

Country:

Lesotho

Region:

Africa

Crew on board:

Crew fatalities:

Pax on board:

Pax fatalities:

Other fatalities:

Total fatalities:

Circumstances:

Shortly after takeoff, while in initial climb, one of the engine failed. The crew reduced his altitude and completed an emergency landing past the runway end. There were no casualties while the aircraft was damaged beyond repair.

Probable cause:

Engine failure during initial climb for unknown reasons.

Crash of a De Havilland DHC-6 Twin Otter 200 in Córdoba

Date & Time: May 25, 1984

Type of aircraft:

Operator:

Registration:

T-83

Flight Phase:

Flight Type:

Military

Survivors:

Site: