Crash of a De Havilland DHC-6 Twin Otter 300 near Oksibil: 15 killed

Date & Time: Aug 2, 2009 at 1100 LT
Operator:
Registration:
PK-NVC
Flight Phase:
Survivors:
No
Site:
Schedule:
Jayapura - Oksibil
MSN:
626
YOM:
1979
Flight number:
MZ9760D
Country:
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
12
Pax fatalities:
Other fatalities:
Total fatalities:
15
Captain / Total flying hours:
8387
Captain / Total hours on type:
8387.00
Copilot / Total flying hours:
1207
Copilot / Total hours on type:
1207
Aircraft flight hours:
27336
Circumstances:
On the morning of Sunday, 2 August 2009, a de Havilland DHC-6 Twin Otter aircraft, registered PK-NVC, operated by PT. Merpati Nusantara Airlines as flight number MZ-7960D, departed from Sentani Airport, Jayapura for Oksibil Airport. The flight was planned in accordance with the visual flight rules (VFR). There were 15 persons on board; two pilots, one engineer, 10 adult passengers and two infants. The estimated flight time was 50 minutes. The fuel on board was sufficient for 2 hours and 50 minutes flight time. About 15 minutes prior to the estimated time of arrival at Oksibil the crew of another aircraft informed the Twin Otter crew that the weather in the Oksibil area was partly cloudy. There were no further reports of radio transmissions from the Twin Otter, and it did not arrive at Oksibil. A search was initiated at the time the aircraft would have run out of fuel. On the morning of 4 August 2009, searchers located the wreckage of the Twin Otter at an elevation of about 9,300 feet about 6 Nm from Oksibil. The aircraft was destroyed by impact forces, and all of the occupants were fatally injured.
Probable cause:
The pilots did not maintain visual flight procedures when flying below lowest safe altitude, and the aircraft was flown into cloud in the vicinity of gap north west of Oksibil. In conclusion, the accident was consistent with controlled flight into terrain.
Final Report:

Crash of a De Havilland DHC-6 Twin Otter 300 near Wamena: 3 killed

Date & Time: Jun 29, 2009 at 1601 LT
Operator:
Registration:
PK-BRO
Flight Phase:
Flight Type:
Survivors:
No
Site:
Schedule:
Dekai - Wamena
MSN:
756
YOM:
1981
Country:
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
3
Circumstances:
The twin engine aircraft departed Dekai Airport at 1530LT on a cargo flight to Wamena, carrying three crew members and a load of 1,600 kilos of various goods. Between 1554LT and 1600LT, the crew was in contact with Wamena. At 1601LT, while cruising at an altitude of 9,600 feet in limited visibility, the aircraft collided with a mountain slope. The wreckage was found a day later about 19 km southeast from Wamena. The aircraft disintegrated on impact and all three occupants were killed.
Probable cause:
Controlled flight into terrain after the crew was flying under VFR mode in IMC conditions. IFR approach to Wamena are not possible, VFR only.

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

Date & Time: Jun 2, 2009 at 1009 LT
Operator:
Registration:
8Q-MAG
Flight Type:
Survivors:
Yes
Schedule:
Male - Halaveli
MSN:
224
YOM:
1969
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
4
Pax fatalities:
Other fatalities:
Total fatalities:
0
Captain / Total flying hours:
3556
Captain / Total hours on type:
3240.00
Copilot / Total flying hours:
1974
Copilot / Total hours on type:
1688
Aircraft flight hours:
33685
Circumstances:
The 8Q-MAG aircraft departed at 0945hrs, with 3 crew and 4 passengers on board, for a Photo Flight around the Lagoon of Halaveli (North Ari Atoll) from the floating platform ( fixed to jetty) of Halaveli (North Ari Atoll). The sky was clear with good visibility and wind, 8-10 knots, from westerly direction. The estimated flight time for the flight was 40 minutes. The aircraft took off westbound. After levelling the aircraft the co-pilot gave his seat to the cameraman, one of the passengers. The co-pilot remained at third row left seat from thereon until the aircraft met the accident. According to the crew and passengers the aircraft made few orbits (right bank) around the island at the initial levelled height and, then descended lower heights and made few more orbits around the lagoon for photography. The passenger seated at the cabin wearing the headset informed the PIC that they got all the shots they wanted and now he could land. PIC started a descending turn (right bank) while keeping the passenger at the co-pilot seat in order to give a different view to him. Before the PIC could complete the turn, the right wing and/or float hit the water. The accident resulted in both wings being broken at the root. Left float was detached and right float got stuck, between the engine and the fuselage, blocking the co-pilot exit. Empennage was twisted upside down. The depth of the lagoon at the site of wreckage was about 1 meter. All the passengers and crew were able to escape the aircraft without any fatalities.
Probable cause:
It was observed by the investigation team that;
• The PIC was conducting flying activities (photographic activities) lower than that allowed in regulations and company operations manual and standard operating procedures.
• At the time of accident a passenger was occupying the co-pilot seat.
• PIC could not make a fair judgment of the aircraft altitude by looking outside since the aircraft was banking to the right for a turn and the co-pilot seat was occupied by a passenger.
• The crew of the aircraft acted swiftly to save lives, after the aircraft came to a halt.
• Investigation revealed that the right float forward and both wingtips were severely damaged. Since the aircraft was right banked at the impact it was evident that the right wing and/or float were the first to impact with the water.
Final Report:

Crash of a De Havilland DHC-6 Twin Otter 100 in La Ronge

Date & Time: Feb 4, 2009 at 0915 LT
Operator:
Registration:
C-FCCE
Flight Phase:
Survivors:
Yes
Schedule:
La Ronge – Deschambeault Lake
MSN:
8
YOM:
1966
Country:
Crew on board:
2
Crew fatalities:
Pax on board:
5
Pax fatalities:
Other fatalities:
Total fatalities:
0
Captain / Total flying hours:
14000
Captain / Total hours on type:
11000.00
Copilot / Total flying hours:
625
Copilot / Total hours on type:
425
Circumstances:
The aircraft was taking off from a ski strip east of and parallel to Runway 36 at La Ronge. After the nose ski cleared the snow, the left wing rose and the aircraft veered to the right and the captain, who was the pilot flying, continued the take-off. The right ski, however, was still in contact with the snow. The aircraft became airborne briefly as it cleared a deep gully to the right of the runway. The aircraft remained in a steep right bank and the right wing contacted the snow-covered ground. The aircraft flew through a chain link fence and crashed into trees surrounding the airport. The five passengers and two crewmembers evacuated the aircraft with minor injuries. There was a small fire near the right engine exhaust that was immediately extinguished by the crew.
Probable cause:
Findings as to Causes and Contributing Factors:
1. Contamination on the wings of the aircraft was not fully removed before take-off. It is likely that asymmetric contamination of the wings created a lift differential and a loss of lateral control.
2. Although the operator was not authorized for short take-off and landing (STOL) take-off on this aircraft, the crew conducted a STOL take-off, which reduced the aircraft’s safety margin relative to its stalling speed and minimum control speed.
3. As a result of the loss of lateral control, the slow STOL take-off speed, and the manipulation of the flaps, the aircraft did not remain airborne and veered right, colliding with obstacles beside the ski strip.
Findings as to Risk:
1. The out of phase task requirements regarding the engine vibration isolator assembly, as listed in the operator’s maintenance schedule approval, results in a less than thorough inspection requirement, increasing the likelihood of fatigue cracks remaining undetected.
2. The right engine inboard and top engine mounts had pre-existing fatigue cracks, increasing the risk of catastrophic failure.
Other Findings:
1. The cockpit voice recorder (CVR) contained audio of a previous flight and was not in operation during the occurrence flight. Minimum equipment list (MEL) procedures for logbook entries and placarding were not followed.
2. The Transwest Air Limited safety management system (SMS) did not identify deviations from standard operating procedures.
Final Report:

Crash of a De Havilland DHC-6 Twin Otter 300 in Lukla: 18 killed

Date & Time: Oct 8, 2008 at 0731 LT
Operator:
Registration:
9N-AFE
Survivors:
Yes
Schedule:
Kathmandu – Lukla
MSN:
720
YOM:
1980
Country:
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
16
Pax fatalities:
Other fatalities:
Total fatalities:
18
Captain / Total flying hours:
8185
Captain / Total hours on type:
7180.00
Copilot / Total flying hours:
556
Copilot / Total hours on type:
341
Circumstances:
The aircraft departed Kathmandu-Tribhuvan Airport at 0651LT on a regular schedule service to the Lukla-Tenzing-Hillary Airport. On approach to runway 06, the crew encountered poor visibility due to foggy conditions. Despite the pilot did not establish any visual contact with the ground, he continued the approach when, on short final, the aircraft struck a rock and crashed just below the runway 06 threshold, bursting into flames. The captain was seriously injured while 18 other occupants were killed, among them 12 Germans, 2 Australians and 5 Nepalese.
Probable cause:
Controlled flight into terrain after the captain decided to continue the approach under VFR mode in IMC conditions.

Crash of a De Havilland DHC-6 Twin Otter 300 off North Ari Atoll

Date & Time: Jul 14, 2008 at 1230 LT
Operator:
Registration:
8Q-MAS
Survivors:
Yes
Schedule:
Male - North Ari Atoll
MSN:
445
YOM:
1975
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
14
Pax fatalities:
Other fatalities:
Total fatalities:
0
Captain / Total flying hours:
3150
Captain / Total hours on type:
430.00
Copilot / Total flying hours:
2880
Copilot / Total hours on type:
127
Aircraft flight hours:
49129
Circumstances:
14th July 2008 was a Monday; the busiest day of the week where there is an average of 150-200 movements. 8Q-MAS completed six sectors prior to the accident, with the same flight crew. Sixteen pieces of baggage were loaded, in the aft cabin, with total weight of 458 lbs. The flight manifest signed by Pilot in Command indicated that the aircraft was loaded up to 11874 lbs. The aircraft was boarded with 14 passengers (7 females, 6 males and 1 child) and the flight manifest used approved weights of 77 lbs Child, 181 lbs for male and 141 lbs for female to calculate the aircraft weight. The aircraft had 930 lbs of fuel. This particular aircraft was a short nose twin otter aircraft, with main loading in aft cabin. The MAT seaplane operation was based on a day VFR, non-schedule and a self dispatch system. All pre-flight duties were completed by the crew. The weather was windy and sea was rough. The aircraft departed at 12.11 hrs from MAT dock at Male International Airport, Water Aerodrome to Adaaran Club Bathala with 14 passengers total: 10 passengers to Adaaran Club Bathala, 2 passengers to Nika Maldives and 2 Passengers to W Retreat and Spa (Fesdu). The estimated flight time to destination was 20 minutes. The W Retreat and Spa Maldives Resort’s Speed Boat (Angelina) (a 34 ft Triana Express) was moored at a buoy (located at 04 04’ 43.6” N, 072 56’ 37.1” E) used by MAT to moor the aircrafts for night stops. The floating platform was located (04 04’ 43.5”N, 072 56’ 38.8”E) east of the buoy. The distance between the floating platform and buoy is around 165 feet. Around 12:30 the aircraft approached for landing near the floating platform. The wind was on a westerly direction 20 to 25 knots and the aircraft approached for a westbound landing. The aircraft made an orbit over the lagoon to inspect the water. The aircraft did a touchdown and was cutting the wave tops to find an appropriate location to stop, when it hit a big wave and was airborne. The aircraft veered to the left. The PIC declared to do a go around. The crew action was 10 degree flap, full throttle and Max Prop RPM. On climb the aircraft collided with the Speed Boat and the aircraft veered to the right and PIC was able to land on LH float.
Probable cause:
Causal Factors:
• The crew’s decision to land on rough waters without giving due considerations for a rejected landing and obstacles nearby was a causal factor.
• The Speed Boat moored to a buoy, close to the landing area was also a causal factor.
Final Report:

Crash of a De Havilland DHC-6 Twin Otter 300 near Cochamó: 3 killed

Date & Time: Jul 2, 2008 at 1430 LT
Operator:
Registration:
947
Flight Phase:
Flight Type:
Survivors:
No
Site:
Schedule:
Puerto Montt - Puerto Montt
MSN:
404
YOM:
1974
Country:
Crew on board:
3
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
3
Circumstances:
The crew departed Puerto Montt-El Tepual for a training flight. En route, the twin engine aircraft collided with the cables of a 23,000 volts powerline and crashed on a hilly terrain, bursting into flames. All three crew members were killed.

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

Date & Time: Jun 18, 2008 at 1001 LT
Operator:
Registration:
N656WA
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
Hyannis - Nantucket
MSN:
47
YOM:
1967
Flight number:
WIG6601
Crew on board:
1
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
1
Captain / Total flying hours:
3607
Captain / Total hours on type:
99.00
Aircraft flight hours:
38185
Circumstances:
The pilot contacted air traffic control and requested clearance to taxi for departure approximately an hour after the scheduled departure time. About 4 minutes later, the flight
was cleared for takeoff. A witness observed the airplane as it taxied, and found it strange that the airplane did not stop and "rev up" its engines before takeoff. Instead, the airplane taxied into the runway and proceeded with the takeoff without stopping. The airplane took off quickly, within 100 yards of beginning the takeoff roll, became airborne, and entered a steep left bank. The bank steepened, and the airplane descended and impacted the ground. Post accident examination of the wreckage revealed that the pilot's four-point restraint was not fastened and that at least a portion of the cockpit flight control lock remained installed on the control column. One of the pre-takeoff checklist items was, "Flight controls - Unlocked - Full travel." The airplane was not equipped with a control lock design, which, according to the airframe manufacturer's previously issued service bulletins, would "minimize the possibility of the aircraft becoming airborne when take off is attempted with flight control locks inadvertently installed." In 1990, Transport Canada issued an airworthiness directive to ensure mandatory compliance with the service bulletins; however, the Federal Aviation Administration did not follow with a similar airworthiness directive until after the accident.
Probable cause:
The pilot's failure to remove the flight control lock prior to takeoff. Contributing to the accident was the Federal Aviation Administration's failure to issue an airworthiness directive making the manufacturer's previously-issued flight control lock service bulletins mandatory.
Final Report:

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

Date & Time: Jun 8, 2008
Operator:
Registration:
5A-DAU
Flight Type:
Survivors:
Yes
Schedule:
Sidra - Sidra
MSN:
570
YOM:
1977
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
0
Circumstances:
The crew was completing a local training flight at Sidra Airport when the accident occurred in unknown circumstances. The aircraft came to rest in a sandy area with its undercarriage and left wing sheared off. Both pilots evacuated safely.

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

Date & Time: Apr 4, 2008
Operator:
Registration:
T-84
Flight Phase:
Flight Type:
Survivors:
Yes
MSN:
214
YOM:
1969
Country:
Crew on board:
2
Crew fatalities:
Pax on board:
4
Pax fatalities:
Other fatalities:
Total fatalities:
0
Circumstances:
Shortly after takeoff from Comodoro Rivadavia Airport, while climbing, the crew encountered an unexpected situation and was forced to attempt an emergency landing. The aircraft crash landed in a desert area located about 10 km from the airport. While all six occupants escaped uninjured, the aircraft was damaged beyond repair.