De Havilland DHC-6 Twin Otter

A DHC-6 Twin Otter aircraft was returning from Woitape, Central Province, to Jacksons Airport, Port Moresby on the morning of 20 September 2014 on a charter flight under the instrument flight rules (IFR). The weather at Woitape was reported to have been clear, but at Port Moresby the reported weather was low cloud and rain. Witnesses reported that the summit of Mt Lawes (1,700 ft above mean sea level (AMSL)) was in cloud all morning on the day of the accident. When the aircraft was 36 nm (67 km) from Port Moresby, air traffic control gave the flight crew a clearance to descend maintaining visual separation from terrain and to track to a left base position for runway 14 right (14R) at Jacksons Airport, Port Moresby. The clearance was accepted by the crew. When the aircraft was within 9.5 nm (17.5 km) of the airport, the pilot in command (PIC) contacted the control tower and said that they were “running into a bit of cloud” and that they “might as well pick up the ILS [instrument landing system] if it’s OK”. The flight crew could not have conducted an ILS approach from that position. They could have discontinued their visual approach and requested radar vectoring for an ILS approach. However, they did not do so. The Port Moresby Aerodrome Terminal Information Service (ATIS), current while the aircraft was approaching Port Moresby had been received by the flight crew. It required aircraft arriving at Port Moresby to conduct an ILS approach. The PIC’s last ILS proficiency check was almost 11 months before the accident flight. A 3-monthly currency on a particular instrument approach is required under PNG Civil Aviation Rule 61.807. It is likely the reason the PIC did not request a clearance to intercept the ILS from 30 nm (55.5 km) was that he did not meet the currency requirements and therefore was not authorized to fly an ILS approach. During the descent, although the PIC said to the copilot ‘we know where we are, keep it coming down’, it was evident from the recorded information that his assessment of their position was incorrect and that the descent should not have been continued. The PIC and copilot appeared to have lost situational awareness. The aircraft impacted terrain near the summit of Mt Lawes and was substantially damaged by impact forces. Both pilots and one passenger were fatally injured in the impact, and one passenger died on the day after the accident from injuries sustained during the accident. Of the five passengers who survived the accident, three were seriously injured and two received minor injuries. One of the fatally injured passengers was not wearing a seat belt.

On 16 February 2014, the Twin Otter (DHC6/300) aircraft with registration number 9N-ABB, owned and operated by Nepal Airlines Corporation (NAC), departed Kathmandu at 0610 UTC (1155 LT) on its schedule flight to Jumla carrying 18 persons on board including 3 crews. Detailed sectors to be covered by the flight No. RA 183/718 was Kathmandu–Pokhara–Jumla-Nepālganj (Night stop). Flight from Kathmandu to Pokhara completed in normal condition. After 17 minutes on ground at Pokhara airport and refueling 9N-ABB departed Pokhara at 0658 for Jumla. After Jumla flight, the aircraft was scheduled to Night stop at Nepālganj. Next day it was to do a series of shuttle flights from Nepālganj. Prevailing westerly weather had a severe impact on most of the domestic flights since last two days. A.M.E. of Engineering Department of NAC who had performed D.I. of 9N ABB had mentioned in his written report to the Commission that he had reminded the diversion of Bhojpur flight of NAC due weather and asked the Captain whether he had weather briefing of the Western Nepal or not. In response to the AME's query the Captain had replied casually that- "weather is moving from west to east and now west is improving". Pilots behavior was reported normal by the ground staffs of Kathmandu and Pokhara airports prior to the commencement of flight on that day. All the pre and post departure procedure of the flight were completed in normal manner. Before departure to Jumla from Pokhara, Pilots obtained Jumla and Bhairahawa weather and seems to be encouraged with VFR Weather at both stations. However, they were unable to make proper assessment of en route weather. PIC decided to remain south of track to avoid the terrain and weather. CVR read out revealed that pilots were aware and concerned about the icing conditions due to low outside air temperature. After around 25 minutes, probably maneuvering to avoid weather, the PIC instructed the co-pilot to plan a route further south of their position, to fly through the Dang valley. The copilot selected Dang in the GPS, on a bearing of 283°, and determined the required altitude was 8500ft. He then raised concerns that the aircraft may not have enough fuel to reach the planned destination. Approximately two and a half minutes before the accident, the PIC initiated a descent, and the copilot advised against this. As per CVR read out, last heading recorded by copilot, approximately one minute before the crash, was 280. The last one minute was a very critical phase of the flight during which PIC said I am entering (perhaps inside the cloud). At that time copilot called Bhairahawa Tower on his own and got latest Bhairahawa weather. While copilot was transmitting its last position report to Bhairahawa Control Tower (approximately 25 miles from Bhairahawa), PIC interrupted and declared to divert Bhairahawa. Bhairahawa Control Tower wanted the pilots to confirm their present position. But crews were very much occupied and copilot said STANDBY. Just few seconds before crash copilot had told PIC not to descend. Copilot also suggested PIC in two occasions - sir don't turn. Very unfortunately aircraft was crashed. The aircraft disintegrated on impact and all 18 occupants were killed.

A de Havilland Canada DHC-6 Twin Otter 310, operated by MASwings, sustained substantial damage in an accident at Kudat Airport (KUD), Malaysia. The copilot and one passenger died, four others were injured. MASwings flight MH3002 operated on a domestic flight from Kota Kinabalu Airport (BKI) to Kudat. The captain was the pilot flying for this sector and the first officer was pilot monitoring. As the aircraft was approaching Kudat Airfield, Kudat Tower reported the weather conditions to be: wind at 270 degrees at 17 kts gusting 31 kts. The aircraft continued the approach on runway 04 and leveled off at 500 feet with flaps set at 10°. At this point the crew noticed that the approach for runway 04 had a strong tail wind. This was evident from the indicated airspeed observed by the crew which indicated 100 kts where the airspeed for flaps 10° should be 65kts. The windsock also indicated a tail wind. Noticing the approach for runway 04 was a tail wind condition, the crew decided to go around at a height of 500ft. Maintaining runway heading, the crew initiated a go around climbing to 1,000ft making a left tear drop and reposition for runway 22. On the approach for runway 22 the captain informed the first officer that if they could not land they would return to Kota Kinabalu. The aircraft was aligned with the centerline of runway 22 and 20° flaps was set. The aircraft continued to descend to 300ft. At this point the wind appeared to be calm as the aircraft did not experience any turbulence and the captain told the first officer that he was committed to land. Upon reaching 200ft the captain called for the flaps to be lowered to full down. As they were about to flare the aircraft to land, approximately 20ft above the runway, the aircraft was suddenly hit by a gust of wind which caused the aircraft to veer to the right with the right wing low and left wing high and the nose was pointing 45° to the right of runway 22. The crew decided to go around by applying maximum power; however the aircraft did not manage to climb successfully. The flaps were not raised and were still in the full flaps down position as the crew thought the aircraft was still low hence the flaps were not raised. The aircraft continued to veer to the right with right wing low and managed to only climb at a shallow rate. The aircraft failed to clear the approaching trees ahead and was unable to continue its climb because the airspeed was reducing. The presence of a full flaps configuration made it more difficult for the aircraft to climb. As the aircraft was on full power on both the engines, it continued to fly almost perpendicularly in relation to the runway and at a low height above the ground. The aircraft hit a tree top at the airfield perimeter fencing, disappeared behind the row of trees, hit another tree behind a house. It hit the right rear roof of the house, ploughed through the roof top of the kitchen, toilet and dining area, hit the solid concrete pillars of the car garage and finally hit the lamp post just outside the house fence. It swung back onto the direction of the runway and came to rest on the ground with its left engine still running. A woman and her 11-year old son who were in the living room at the time escaped unhurt.

The Twin Otter (DHC6/300) aircraft with registration number 9N-ABO, owned and operated by Nepal Airlines Corporation (NAC), departed Kathmandu to Pokhara for night stop on 15 May 2013 in order to accomplish up to 5 (five) Pokhara-Jomsom-Pokhara charter flights planned for the subsequent day on 16 May 2013. As per the programme, the aircraft completed first charter flight from Pokhara to Jomsom sector on 16 May 2013 morning after one and half hour waiting on ground due weather. For this second flight, the aircraft departed at 0225 UTC (08:10LT) from Pokhara to Jomsom in the command of Capt. Dipendra Pradhan and Mr. Suresh K.C. as co-pilot. There were 19 passengers including one infant and 3 crew members on board. The aircraft was operating under Visual Flight Rules (VFR). As per the CVR readout there was no reported difficulties and all the pre and post departure procedure and en-route portion of the flight were completed in normal manner. There was no indication of lacking of information and advice from Jomsom Tower. At first contact the co-pilot called Jomsom Tower and reported its position at PLATO (a compulsory reporting point) at 9 miles from Jomsom airport at 12500ft. AMSL. The Jomsom Tower advised runway 24 wind south westerly 08-12 KTS, QNH 1020, Temp 13 degree and advised to report downwind for runway 24.The co-pilot accepted by replying to join downwind for runway 24. There was no briefing and discussion between the two pilots regarding the tail wind at the airport. The PIC, then, took over the communication function from co-pilot and called Jomsom Tower, requesting to use runway 06 instead of runway 24, despite the advice of tower to use runway 24 to avoid tail wind effect in runway 06. Jomsom Tower repeated the wind speed to be 08-12 KTS for the runway 06, to which the PIC read back the wind and answered to have ”no problem”. As per the PIC request the Jomsom Tower designated runway 06 for landing and advised to report on final runway 06. The PIC did read back the same. The pre landing checklist was used, flaps with full fine in propeller rpm were taken and full flaps was also taken before touchdown. In the briefing of “missed approach” the PIC had answered to be “standard”. The aircraft touched down runway of Jomsom airport at 0245 UTC (08:30LT) at a distance of approximately 776 ft, far from the threshold of runway 06. After rolling 194 ft. in the runway, the aircraft left runway and entered grass area in the right side. The aircraft rolled around 705 ft in the grass area and entered the runway again. The maximum deviation from the runway edge was 19 ft. The Commission has observed that when aircraft touched down the runway, it was not heading in parallel to the runway centreline. After touchdown the aircraft rolled around 194ft on the runway, left the paved area and started rolling in the grass area in the right side. During the landing roll, when the aircraft was decelerating, the co-pilot had raised the flaps as per the existing practice of carrying out “after the landing “checks". As per the observation of passenger seated just behind the cockpit, after touchdown of the aircraft there was no communication between pilot and co-pilot. It seemed that pilot was busy in cockpit and facing problem. It was obvious that PIC was in dilemma in controlling aircraft. He added power to bring aircraft into the runway with an intention to lift up the aircraft. He did not brief anything to copilot about his intention and action. He started adding power with the intention of lifting up, but the aircraft was already losing its speed, due to extension of flaps by co-pilot without briefing to PIC and use of brakes (light or heavy, knowingly and unknowingly) simultaneously by the PIC. The accelerating aircraft with insufficient speed and lift to take off ran out of the runway 24 end, continued towards the river, hit the barbed fence and gabion wall with an initial impact and finally fell down into the edge of river. The left wing was rested in the mid of the river preventing the aircraft submerged into the river.

Shortly after takeoff from Sam Neua-Nathong Airport, while in initial climb, the twin engine aircraft collided with trees, lots height and crashed in a small river located 200 metres past the runway end. All 18 occupants were injured, five seriously. The aircraft was damaged beyond repair.

The aircraft departed South Pole Station, Antarctica, at 0523 Coordinated Universal Time on 23 January 2013 for a visual flight rules repositioning flight to Terra Nova Bay, Antarctica, with a crew of 3 on board. The aircraft failed to make its last radio check-in scheduled at 0827, and the flight was considered overdue. An emergency locator transmitter signal was detected in the vicinity of Mount Elizabeth, Antarctica, and a search and rescue effort was initiated. Extreme weather conditions hampered the search and rescue operation, preventing the search and rescue team from accessing the site for 2 days. Once on site, it was determined that the aircraft had impacted terrain and crew members of C-GKBC had not survived. Adverse weather, high altitude and the condition of the aircraft prevented the recovery of the crew and comprehensive examination of the aircraft. There were no indications of fire on the limited portions of the aircraft that were visible. The accident occurred during daylight hours.

The seaplane landed hard in the Caballococha's Laguna. Upon landing on water, the right float was torn off, the aircraft overturned and sank. All 11 occupants were rescued and the aircraft was damaged beyond repair. It was performing a flight from Iquitos on behalf of the 42nd Group of the Peruvian Air Force.

The float-equipped de Havilland DHC-6-300 Twin Otter (registration C-GARW, serial number 367) was landing at the float-plane base (CEN9) located in Yellowknife, Northwest Territories, along the western shore of Great Slave Lake, beside the area known as Old Town. There were 2 crew members and 7 passengers on board, and the first officer was the pilot flying. On touchdown, the aircraft bounced, porpoised and landed hard on the right float. The flight crew initiated a go-around; the aircraft lifted off at low speed in a nose-high, right-wing-low attitude, and it continued in a right turn towards the shore. As the turn continued, the aircraft’s right wing contacted power lines and cables before the float bottoms impacted the side of an office building. The aircraft then dropped to the ground on its nose and cart-wheeled into an adjacent parking lot. Both crew members were fatally injured, 4 passengers were seriously injured, and 3 passengers sustained minor injuries. The aircraft was substantially damaged. The 406-megahertz emergency locator transmitter activated. There was no fire. The accident occurred at 1318 Mountain Daylight Time.