Crash of a De Havilland DHC-6 Twin Otter 100 near Eureka

Date & Time: Aug 14, 1973
Operator:
Registration:
CF-WWP
Flight Phase:
Survivors:
Yes
MSN:
12
YOM:
1966
Location:
Country:
Crew on board:
2
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
0
Circumstances:
Crashed in unknown circumstances 70 km east of Eureka, NWT. Both occupants were injured and the aircraft was damaged beyond repair.

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

Date & Time: Apr 18, 1973
Operator:
Registration:
YA-GAT
Flight Phase:
Survivors:
Yes
Schedule:
Bamyan - Kabul
MSN:
111
YOM:
1968
Location:
Country:
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
16
Pax fatalities:
Other fatalities:
Total fatalities:
4
Circumstances:
At liftoff at Bamyan Airport, the twin engine airplane went out of control and crashed. Both pilots and two passengers were killed while 15 other occupants were injured. All passengers were US and Canadian citizens.

Crash of a De Havilland DHC-6 Twin Otter 100 in Savoy: 1 killed

Date & Time: Mar 26, 1973 at 0510 LT
Operator:
Registration:
N7705
Flight Phase:
Survivors:
No
Schedule:
Savoy - Chicago
MSN:
5
YOM:
1966
Crew on board:
1
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
1
Captain / Total flying hours:
2745
Captain / Total hours on type:
60.00
Circumstances:
After takeoff from Savoy-Willard Airport, while in initial climb, the airplane encountered difficulties to gain height, stalled and crashed in flames in an open field. The pilot, sole on board, was killed.
Probable cause:
Inadequate preflight preparation on part of the pilot who failed to realize that the gust locks were still engaged at takeoff. Unfavorable wind conditions was considered as a contributing factor.
Final Report:

Crash of a De Havilland DHC-6 Twin Otter 100 near Nabire: 13 killed

Date & Time: Feb 28, 1973
Operator:
Registration:
PK-NUC
Flight Phase:
Survivors:
No
Site:
MSN:
70
YOM:
1967
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
11
Pax fatalities:
Other fatalities:
Total fatalities:
13
Circumstances:
Crashed in unknown circumstances in a mountainous area located about 45 km east of Nabire. All 13 occupants have been killed.

Crash of a De Havilland DHC-6 Twin Otter 200 near Pudasjärvi

Date & Time: Feb 5, 1973 at 1004 LT
Operator:
Registration:
OH-KOA
Flight Phase:
Survivors:
Yes
Schedule:
Oulu - Kuusamo
MSN:
166
YOM:
1968
Flight number:
KR482
Country:
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
15
Pax fatalities:
Other fatalities:
Total fatalities:
0
Aircraft flight hours:
3128
Circumstances:
Kar-Air flight KR482 took off from Oulu Airport, Finland on a scheduled domestic service to Kuusamo. The aircraft climbed to FL70 and initially flew above the cloud layer. Before the aircraft started descent, it had been informed on the radio of the prevailing weather at Kuusamo Airport: surface wind 160°, 6 KT occasionally 10 KT, visibility 10 km, clouds 8/8 1000 feet, temperature -7°C, QNH 989 mb. After the aircraft had left its cruising level at approximately 07:24 GMT it entered icing conditions in clouds between 6000 and 5000 feet. When approaching 3000 feet, the right engine of the aircraft suddenly lost its power. The crew immediately feathered the right-hand propeller, changed to single-engine flight and turned back in the direction of Oulu while informing Kuusamo Airport ATC about the incident. Kuusamo ATC cleared the aircraft to FL 60 for the return flight to Oulu. The crew reported that the flight back to Oulu would last one hour and at the same time stated that the climbing performance of the aircraft did not permit a climb to the planned FL 60. The crew asked for FL 30 as its flight altitude and was cleared to that level by the ATC. After the engine failure the pilot-in-command had intended to climb to FL 60, where flight in clear air and without the danger of icing had been possible. Because of the icing of the aircraft, its climbing performance when flying on one engine had, however, not been sufficient for a climb to FL 60. The aircraft had been able to climb about 700 feet to reach an altitude of appr. 3700 feet but was incapable of increasing the altitude above that level. The aircraft had continued its flight in the direction of Oulu but began to continually lose altitude because of increased icing in spite of the engine power being used in the left engine exceeding the maximum continuous thrust values. The aircraft had at the end of the flight been given an estimation of the altitude of the prevailing cloudbase in the region, which was reported to be 300-500 feet. As the loss of height continued, the crew had hoped that they would get below the cloudbase and the ice formed on the aircraft would fall off or that they would be able to make a landing in the terrain choosing a suitable place for emergency landing. However, the weather in the region had been such that there was practically no clearance between the clouds and the terrain. The aircraft had lost so much height by the time it had arrived at the area of Naamanka village in Pudasjarvi parish that the first landmark the co-pilot had seen had been a trigonometric tower which the aircraft passed over by only a few metres. About three kilometres after the passing of the tower, while the pilot-in-command was trying to pick out a landing place and having difficulties to control the aircraft, it had at 08:04 GMT struck the trees and hit the ground in a swampy, sparsely wooded area 5 km north of Linattijarvi. As a result of the impact three persons were quite badly injured while the others received only minor injuries, contusions, and bruises, and the aircraft was destroyed beyond repair.
Source: ASN
Probable cause:
The main reason for the aircraft accident has been the sudden breakdown of the turbine of the right engine so that the engine has lost its power and flight on one engine in icing conditions has become inevitable. The icing on the wet surfaces of the aircraft which lacked de-icing and anti-icing equipment and the consequent deterioration in the performance of the aircraft was decisively contributory to the accident. The performance of the aircraft when flying on one engine has been insufficient after the icing had taken place considering the weight of the aircraft at the time of the accident.

Crash of a De Havilland DHC-6 Twin Otter off Sint Maarten: 13 killed

Date & Time: Dec 21, 1972
Operator:
Registration:
F-OGFE
Survivors:
No
Schedule:
Pointe-à-Pitre - Sint Maarten
MSN:
258
YOM:
1969
Crew on board:
2
Crew fatalities:
Pax on board:
11
Pax fatalities:
Other fatalities:
Total fatalities:
13
Circumstances:
The Twin Otter was approaching Sint Maarten-Princess Juliana Airport by night when it crashed in unknown circumstances into the sea few km offshore. The aircraft was destroyed and all 13 occupants were killed.

Crash of a De Havilland DHC-6 Twin Otter 100 in Segundo Corral: 3 killed

Date & Time: Nov 17, 1972
Operator:
Registration:
938
Flight Phase:
Flight Type:
Survivors:
No
MSN:
16
YOM:
1966
Country:
Crew on board:
3
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
3
Circumstances:
The aircraft suffered an engine failure in flight and the crew elected to divert to Segundo Corral Airport when the airplane crashed. All three crew members were killed.
Probable cause:
Engine failure in flight.

Crash of a De Havilland DHC-6 Twin Otter 300 in Tha Tham Bleung: 3 killed

Date & Time: Jul 25, 1972 at 1050 LT
Operator:
Registration:
N5662
Flight Phase:
Flight Type:
Survivors:
Yes
Schedule:
Vientiane - Vientiane
MSN:
326
YOM:
1971
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
2
Pax fatalities:
Other fatalities:
Total fatalities:
3
Captain / Total flying hours:
14258
Captain / Total hours on type:
480.00
Circumstances:
The airplane was engaged in a supply mission out from Vientiane-Wattay Airport, carrying two passengers, two crew and a load of 2,780 pounds of food. While approaching the drop zone and flying below the cloud base, the pilot-in-command initiated a steep turn to the left when the airplane stalled and crashed. A passenger survived while three other occupants were killed. It is believed that the aircraft's speed was too low during the last turn, causing it to stall and to crash.
Final Report:

Crash of a De Havilland DHC-6 Twin Otter 100 on Mt Lille Tussen: 17 killed

Date & Time: Jul 11, 1972 at 1543 LT
Operator:
Registration:
67-056
Flight Phase:
Flight Type:
Survivors:
No
Site:
Schedule:
Bardufoss - Stokmarknes - Bodø
MSN:
56
YOM:
1967
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
15
Pax fatalities:
Other fatalities:
Total fatalities:
17
Circumstances:
Prior to departure from Bardufoss to Stokmarknes, the crew was informed about the poor weather conditions en route and the captain was instructed to continue directly to Bodø. Despite these instructions, he decided after takeoff to fly to Stokmarknes. While in cruising altitude, the crew encountered poor weather conditions with low clouds, fog and rain falls when the airplane struck the slope of Mt Lille Tussen (800 meters high) located on the Grytøya Island, about 75 km northeast of the Stokmarknes-Skagen Airport. The wreckage was found 20 meters below the summit and all 17 occupants were killed.
Probable cause:
The accident was the consequence of a controlled flight into terrain that occurred in poor weather conditions consisting of low clouds, fog and rain falls. For unknown reason, the captain decided to fly to Stokmarknes despite the instructions received prior to departure. It was determined that the night before the flight, the captain had a party and failed to observe sufficient rest time. It was also reported that the captain's blood showed an alcohol concentration estimated between 1 and 1,5‰.

Crash of a De Havilland DHC-6 Twin Otter 200 near Appleton: 8 killed

Date & Time: Jun 29, 1972 at 1037 LT
Operator:
Registration:
N4043B
Survivors:
No
Schedule:
Chicago - Sheboygan - Appleton
MSN:
13
YOM:
1966
Flight number:
ZW671
Crew on board:
2
Crew fatalities:
Pax on board:
6
Pax fatalities:
Other fatalities:
Total fatalities:
8
Captain / Total flying hours:
6556
Captain / Total hours on type:
3412.00
Copilot / Total flying hours:
4309
Copilot / Total hours on type:
1685
Aircraft flight hours:
15664
Circumstances:
Following a uneventful flight from Sheboygan, the crew started the descent to Appleton Airport in relative good weather conditions when, at an altitude of 2,500 feet, the Twin Otter collided with a North Central Airlines Convair CV-580 registered N90858. En route from Green Bay to Oshkosh, the Convair was carrying two passengers and three crew members. At the time of the accident, both airplanes were flying under VFR in an uncontrolled airspace. Following the collision, both aircraft crashed into Lake Winnebago, some five miles southeast of Appleton Airport. Debris were found floating on water, both airplanes were totally destroyed and all 13 occupants were killed.
Probable cause:
The failure of both flight crews to detect visually the other aircraft in sufficient time to initiate evasive action. the Board is unable to determine why each crew failed to see and avoid the other aircraft; however, the Board believes that the ability of both crews to detect the other aircraft in time to avoid a collision was reduced because of the atmospheric conditions and human visual limitations.
Final Report: