Crash of a De Havilland DHC-2 Beaver off Cottage Point: 6 killed

Date & Time: Dec 31, 2017 at 1515 LT
Type of aircraft:
Operator:
Registration:
VH-NOO
Flight Phase:
Survivors:
No
Schedule:
Cottage Point - Sydney
MSN:
1535
YOM:
1963
Country:
Region:
Crew on board:
1
Crew fatalities:
Pax on board:
5
Pax fatalities:
Other fatalities:
Total fatalities:
6
Captain / Total flying hours:
10762
Aircraft flight hours:
21872
Circumstances:
On 31 December 2017, at about 1045 Eastern Daylight-saving Time, five passengers arrived via water-taxi at the Sydney Seaplanes terminal, Rose Bay, New South Wales (NSW) for a charter fly-and-dine experience to a restaurant at Cottage Point on the Hawkesbury River. Cottage Point is about 26 km north of Sydney Harbour in the Ku-ring-gai Chase National Park, a 20 minute floatplane flight from Rose Bay. At about 1130, prior to boarding the aircraft, the passengers received a pre-flight safety briefing. At about 1135, the pilot and five passengers departed the Rose Bay terminal for the flight to Cottage Point via the northern beaches coastal route, in a de Havilland Canada DHC-2 Beaver floatplane, registered VH-NOO and operated by Sydney Seaplanes. The flight arrived at Cottage Point just before midday and the passengers disembarked. The pilot then conducted another four flights in VH-NOO between Cottage Point and Rose Bay. The pilot arrived at Cottage Point at about 1353. After securing the aircraft at the pontoon and disembarking passengers from that flight, the pilot walked to a kiosk at Cottage Point for a drink and food. At about 1415, the pilot received a phone call from the operator via the kiosk, asking the pilot to move the aircraft off the pontoon, which could only accommodate one aircraft at a time. This was to allow the pilot of the operator’s other DHC-2 aircraft (VH-AAM) to pick-up other restaurant passengers. The pilot of VH-NOO immediately returned to the aircraft and taxied away from the pontoon into Cowan Creek. The operator’s records indicated that VH-AAM arrived at the pontoon and shut down the engine at about 1419, and subsequently departed at about 1446. The pilot of VH-NOO returned to the pontoon after having taxied in Cowan Creek with the engine running for up to 27 minutes, while waiting for the other aircraft. During the taxi, closed-circuit television footage from a private residence at Cottage Point showed VH-NOO at 1444, with the pilot’s door ajar. After shutting down the aircraft, the pilot briefly went into the restaurant to see if the passengers were ready to leave, and then returned to the aircraft. The return flight to Rose Bay, scheduled to depart at 1500, provided sufficient time for the passengers to meet a previously booked water-taxi to transport them from Rose Bay to their hotel at 1545. At about 1457, the passengers commenced boarding the aircraft and at around 1504, the aircraft had commenced taxiing toward the designated take-off area in Cowan Creek. At about 1511, the aircraft took off towards the north-north-east in Cowan Creek, becoming airborne shortly before passing Cowan Point. The aircraft climbed straight ahead before commencing a right turn into Cowan Water. A witness, who was travelling east in a boat on the northern side of Cowan Water, photographed the aircraft passing over a location known as ‘Hole in the wall’. These photographs indicated that the aircraft was turning to the right with a bank angle of 15-20°. Witnesses observed the right turn continue above Little Shark Rock Point and Cowan Water. The last photograph taken by the passenger was when the aircraft was heading in a southerly direction towards Cowan Bay. At that time, the aircraft was estimated to be at an altitude of about 30 m (98 ft).Shortly after the turn in Cowan Water, several witnesses observed the aircraft heading directly towards and entering Jerusalem Bay flying level or slightly descending, below the height of the surrounding terrain. Witnesses also reported hearing the aircraft’s engine and stated that the sound was constant and appeared normal. About 1.1 km after entering Jerusalem Bay, near the entrance to Pinta Bay, multiple witnesses reported seeing the aircraft flying along the southern shoreline before it suddenly entered a steep right turn at low-level. Part-way through the turn, the aircraft’s nose suddenly dropped before the aircraft collided with the water, about 95 m from the northern shore and 1.2 km from the end of Jerusalem Bay. The aircraft came to rest inverted and with the cabin submerged. A number of people on watercraft who heard or observed the impact, responded to render assistance. Those people could not access the (underwater) aircraft cabin. The entire tail section and parts of both floats were initially above the waterline, but about 10 minutes later had completely submerged. The pilot and five passengers received fatal injuries.
Probable cause:
Contributing factors:
- The aircraft entered Jerusalem Bay, a known confined area, below terrain height with a level or slightly descending flight path. There was no known operational need for the aircraft to be
operating in the bay.
- While conducting a steep turn in Jerusalem Bay, it was likely that the aircraft aerodynamically stalled at an altitude too low to effect a recovery before colliding with the water.
- It was almost certain that there was elevated levels of carbon monoxide in the aircraft cabin, which resulted in the pilot and passengers having higher than normal levels of carboxyhaemoglobin in their blood.
- Several pre-existing cracks in the exhaust collector ring, very likely released exhaust gas into the engine/accessory bay, which then very likely entered the cabin through holes in the main
firewall where three bolts were missing.
- A 27 minute taxi before the passengers boarded, with the pilot’s door ajar likely exacerbated the pilot’s elevated carboxyhaemoglobin level.
- It was likely that the pilot's ability to safely operate the aircraft was significantly degraded by carbon monoxide exposure.
- Disposable chemical spot detectors, commonly used in general aviation, can be unreliable at detecting carbon monoxide in the aircraft cabin. Further, they do not draw a pilot's attention to a hazardous condition, instead they rely on the pilot noticing the changing colour of the sensor.
- There was no regulatory requirement from the Civil Aviation Safety Authority for piston-engine aircraft to carry a carbon monoxide detector with an active warning to alert pilots to the presence of elevated levels of carbon monoxide in the cabin. (Safety issue)

Other factors that increased risk:
- It was likely that the effectiveness of the disposable carbon monoxide chemical spot detector fitted to the aircraft was reduced due to sun bleaching.
- Although detectors were not required to be fitted to their aircraft, Sydney Seaplanes had no mechanism for monitoring the serviceability of the carbon monoxide detectors. (Safety issue)
- The in situ bolts used by the maintenance organisation to secure the magneto access panels on the main firewall were worn, and were a combination of modified AN3-3A bolts and non-specific bolts. This increased the risk of the bolts either not tightening securely on installation and/or coming loose during operations.
- The operator relied on volunteered passenger weights without allowances for variability, rather than actual passenger weights obtained just prior to a flight. This increased the risk of underestimating passenger weights and potentially overloading an aircraft.
- The standard passenger weights specified in Civil Aviation Advisory Publication (CAAP) 235-1(1) Standard passenger and baggage weights did not accurately reflect the average weights of the current Australian population. Further, the CAAP did not provide guidance on the use of volunteered passenger weights as an alternative to weights derived just prior to a flight.
- Australian civil aviation regulations did not mandate the fitment of flight recorders for passenger-carrying aircraft under 5,700 kg. Consequently, the determination of factors that influenced this accident, and other accidents, have been hampered by a lack of recorded data pertaining to the flight. This has likely resulted in the non-identification of safety issues, which continue to present a hazard to current and future passengercarrying operations. (Safety issue)
- Annex 6 to the Convention of International Civil Aviation did not mandate the fitment of flight recorders for passenger-carrying aircraft under 5,700 kg. Consequently, the determination of factors that influenced this accident, and numerous other accidents have been hampered by a lack of recorded data pertaining to the flight. This has likely resulted in important safety issues not being identified, which may remain a hazard to current and future passenger carrying operations. (Safety issue)

Other findings:
- It was very likely that the middle row right passenger did not have his seatbelt fastened at the time of impact, however, the reason for this could not be determined.
- The accident was not survivable due to the combination of the impact forces and the submersion of the aircraft.
- The pilot had no known pre-existing medical conditions that could explain the accident.
Final Report:

Crash of a De Havilland DHC-2 Beaver I near Laidman Lake: 1 killed

Date & Time: Oct 10, 2016 at 0844 LT
Type of aircraft:
Registration:
C-GEWG
Flight Phase:
Flight Type:
Survivors:
Yes
Schedule:
Vanderhoof - Laidman Lake
MSN:
842
YOM:
1955
Country:
Crew on board:
1
Crew fatalities:
Pax on board:
4
Pax fatalities:
Other fatalities:
Total fatalities:
1
Captain / Total flying hours:
280
Captain / Total hours on type:
23.00
Circumstances:
On 10 October 2016, at approximately 0820 Pacific Daylight Time, a privately operated de Havilland DHC-2 Beaver aircraft on amphibious floats (registration C-GEWG, serial number 842), departed from Vanderhoof Airport, British Columbia, for a day visual flight rules flight to Laidman Lake, British Columbia. The pilot and 4 passengers were on board. Approximately 24 minutes into the flight, the aircraft struck terrain about 11 nautical miles east of Laidman Lake. The 406 MHz emergency locator transmitter (ELT) activated on impact. The ELT's distress signal was detected by the Cospas-Sarsat satellite system, and a search-and-rescue operation was initiated by the Joint Rescue Coordination Centre Victoria. One of the passengers was able to call 911 using a cell phone. The pilot was fatally injured, and 2 passengers were seriously injured. The other 2 passengers sustained minor injuries. The aircraft was substantially damaged. There was no post-impact fire.
Probable cause:
Findings as to causes and contributing factors:
1. As the aircraft approached the mountain ridge, the high overcast ceiling and uniform snow-covered vegetation were conducive to optical illusions associated with flight in mountainous terrain. These illusions likely contributed to the pilot’s misjudgment of the proximity of the terrain, inadvertent adoption of an increasingly nose-up attitude, and non-detection of the declining airspeed before banking the aircraft to turn away from the hillside.
2. As the angle of bank increased during the turn, the stall speed also increased and the aircraft entered an accelerated stall.
3. The aircraft’s out-of-limit weight-and-balance condition increased its stall speed and degraded its climb performance, stability, and slow-flight characteristics. As a result, its condition, combined with the aircraft’s low altitude, likely prevented the pilot from regaining control of the aircraft before the collision with the terrain.
4. The absence of a stall warning system deprived the pilot of the last line of defence against an aerodynamic stall and the subsequent loss of control of the aircraft.
5. The forward shifting of the unsecured cargo and the partial detachment of the rear seats during the impact resulted in injuries to the passengers.
6. During the impact sequence, the load imposed on the pilot’s lap-belt attachment points was transferred to the seat-attachment points, which then failed in overload. As a result, the seat moved forward during the impact and the pilot was fatally injured.

Findings as to risk:
1. If pilots do not obtain quality sleep during the rest period prior to flying, there is a risk that they will operate an aircraft while fatigued, which could degrade pilot performance.
2. If cargo is not secured, there is a risk that it will shift forward during an impact or turbulence and injure passengers or crew.

Other findings:
1. Because the aircraft was equipped with a 406 MHz emergency locator transmitter that transmitted an alert message to the Cospas-Sarsat satellites system in combination with the homing signal transmitted on 121.5 MHz, the Joint Rescue Coordination Centre aircraft was able to locate the wreckage and occupants in a timely manner.
Final Report:

Crash of a De Havilland DHC-2 Beaver I off Lopez Island

Date & Time: Sep 30, 2016 at 0837 LT
Type of aircraft:
Operator:
Registration:
N6781L
Survivors:
Yes
Schedule:
Kenmore – Roche Harbor
MSN:
788
YOM:
1955
Crew on board:
1
Crew fatalities:
Pax on board:
3
Pax fatalities:
Other fatalities:
Total fatalities:
0
Captain / Total flying hours:
25000
Captain / Total hours on type:
1630.00
Aircraft flight hours:
7395
Circumstances:
While maneuvering at low altitude for a water landing, the commercial pilot of the float equipped airplane encountered low visibility due to ground fog. The pilot initiated a go-around, but the airplane impacted the water, bounced, and impacted the water a second time before coming to rest upright. The airplane subsequently sank, and all four occupants were later rescued. The pilot reported that there were no mechanical anomalies with the airplane that would have precluded normal operation. The operator further reported that other company pilots who were flying on the day of the accident stated that the low visibility conditions were easily avoided by a slight course deviation.
Probable cause:
The pilot's decision to land in an area of low visibility and ground fog, which resulted in collision with water.
Final Report:

Crash of a De Havilland DHC-2 Beaver near Iliamna

Date & Time: Aug 8, 2016 at 1651 LT
Type of aircraft:
Operator:
Registration:
N95RC
Flight Phase:
Survivors:
Yes
Schedule:
Crosswind Lake - King Salmon
MSN:
970
YOM:
1956
Location:
Crew on board:
1
Crew fatalities:
Pax on board:
6
Pax fatalities:
Other fatalities:
Total fatalities:
0
Captain / Total flying hours:
9780
Captain / Total hours on type:
535.00
Aircraft flight hours:
7632
Circumstances:
The airline transport pilot of the float-equipped airplane was attempting a takeoff with the load of passengers that he had flown to the lake earlier in the day. The pilot's calculated takeoff distances for the water run and over a 50-ft obstacle were 1,050 ft and 2,210 ft, respectively. The pilot did not add a safety margin to his takeoff distance calculations. The approximate shore-to-shore distance of the takeoff path was 1,800 ft. During taxi, the pilot retracted the wing flaps, where they remained for the takeoff. GPS data showed that the airplane attained a speed of about 49 knots before impacting terrain just beyond the shoreline. The airplane's stall speed with flaps retracted was about 52 knots. Postaccident examination revealed that the left wing flap was in the fully retracted position; the right wing flap assembly was damaged. The airplane flight manual takeoff checklist stated that flaps were to be selected to the "TAKE-OFF" position before takeoff. Additionally, the takeoff performance data contained in the flight manual was dependent upon the use of "TAKE-OFF" flaps and did not account for no-flaps takeoffs. Even if the pilot had used the correct flap setting for takeoff, the calculated takeoff distances were near the available takeoff distance, and it is likely that the airplane would still not have been able to avoid a collision with terrain. The pilot stated that there was no mechanical malfunction/failure with the airplane, and he should have "done the right thing," which was to conduct two flights, each with a half load of passengers.
Probable cause:
The pilot's decision to perform the takeoff despite calculations showing that the distance available was inadequate, which resulted in impact with terrain.
Final Report: