Date: | Tuesday 3 December 2019 |
Time: | 09:10 |
Type: | Basler BT-67 Turbo 67 (DC-3T) |
Owner/operator: | North Star Air |
Registration: | C-FKAL |
MSN: | 13840 |
Year of manufacture: | 1943 |
Total airframe hrs: | 36496 hours |
Engine model: | Pratt & Whitney Canada PT6A-67R |
Fatalities: | Fatalities: 0 / Occupants: 2 |
Aircraft damage: | Substantial, written off |
Category: | Accident |
Location: | 0,5 km SW of Sachigo Lake Airport, ON (ZPB) -
Canada
|
Phase: | Approach |
Nature: | Cargo |
Departure airport: | Red Lake Airport, ON (YRL/CYRL) |
Destination airport: | Sachigo Lake Airport, ON (ZPB/CZPB) |
Investigating agency: | TSB |
Confidence Rating: | Accident investigation report completed and information captured |
Narrative:The Basler BT-67 aircraft operated by North Star Air, collided with terrain approximately 500 metres southwest of the threshold of runway 10 of Sachigo Lake Airport, Ontario, Canada. The aircraft sustained substantial damage. The 2 flight crew members received no injuries.
The aircraft was operated on a daytime VFR cargo flight from Red Lake Airport (CYRL) to Sachigo Lake Airport (CZPB).
No weather reports for the destination were available, but the captain learned that an airport 30 nm to the southeast reported IMC conditions with an overcast ceiling at 500 feet AGL, with an expected improval to 1500 feet AGL with a possible fluctuation to 700 feet AGL and decreased visibility by 09:00.
The flight departed CYRL under visual flight rules (VFR) at 08:00.
Shortly after takeoff, the aircraft entered, and climbed above, the cloud layers before reaching the planned cruising altitude, which was not in accordance with the applicable regulations for VFR flights. Before commencing the descent to CZPB, the pilots obtained the 08:00 hourly weather report at at the nearby airport, which had remained generally unchanged, and elected to carry out a visual approach to runway 10. The captain initiated a descent through the cloud layers by reference to the flight instruments.
Once the aircraft broke out of cloud at very low level, the aircraft was not in a position to continue with the planned visual approach. The captain made low-level manoeuvres in an attempt to land, flying a large 360° turn, as low as 100 feet AGL (i.e. about 400 feet below the required minimum altitude), and then flew a manoeuvre similar to a left-hand circuit, which brought the aircraft within close proximity to a significant obstacle (a 150-foot tall tower), in meteorological conditions below the VFR minimum requirements. Given that the captain had not briefed the first officer, the latter was unaware of the captains intentions and began calling out airspeed and altitudes. On the last attempt, during the low-level downwind leg, when the aircraft passed abeam the threshold of runway 10, the captain initiated a left-hand turn and began descending. About 10 seconds later, the aircraft collided with terrain, in a near wings-level attitude, approximately 650 feet southwest of the threshold of runway 10. The aircraft slid 350 feet southward along the ground before it came to a rest on a southwesterly heading.
The captain likely experienced attentional narrowing while carrying out a high-workload visual approach at very low altitude in IMC. This most likely resulted in an inadvertent but controlled descent that was not detected until the aircraft collided with terrain.
The uninjured pilots evacuated the aircraft via the right-hand cockpit window. The aircraft sustained substantial damage; however, there was no post-impact fire.
Findings as to causes and contributing factors:
1. The decision to depart on, and continue, a visual flight rules flight in instrument meteorological conditions was influenced by a distorted perception of risk resulting from successful past experience in similar situations.
2. The captain likely experienced attentional narrowing while carrying out a high-workload visual approach at very low altitude in instrument meteorological conditions. This most likely resulted in an inadvertent but controlled descent that was not detected until the aircraft collided with terrain.
3. The result-oriented subculture of some North Star Airs DC3-TP67 pilots, which emphasized mission completion over regulatory compliance, resulted in visual flight rules flights, such as the occurrence flight, being conducted in instrument meteorological conditions.
4. North Star Airs safety management system did not identify the underlying factors that led to the reported instances of company aircraft operating visual flight rules flights into instrument meteorological conditions, nor were any additional measures taken to monitor its DC3-TP67 operation to ensure flights were being conducted in accordance with regulations. As a result, previously identified unsafe practices persisted, and played a direct role in this occurrence.
Accident investigation:
|
| |
Investigating agency: | TSB |
Report number: | A19C0145 |
Status: | Investigation completed |
Duration: | 2 years and 8 months |
Download report: | Final report |
|
Sources:
North Star Air press release TSB
Location
Images:
photo (c) TSB; Sachigo Lake Airport, ON (ZPB); 03 December 2019
Revision history:
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