A transportation Safety Board report into the May 3 emergency landing of a Buffalo Air DC-3 near Hay River has revealed the landing gear was extended early, preventing the aircraft’s speed and altitude to be maintained on approach to the Hay River airport.
Released December 20, the report revealed more details about the emergency landing of a Douglas DC-3 on a cargo flight bound for Yellowknife. The report is what the TSB calls a Class 4, which is usually completed within 200 days and contains “limited analysis” but no findings or recommendations for the wider aviation industry.
The report found that the crew put down the landing gear early during the emergency descent to the Hay River airport.
“There was a misunderstanding of when to lower the landing gear and subsequently the landing gear was lowered too early in the approach to the airport,” said Mike Adam, a senior technical investigator with the TSB in charge of this investigation. “That resulted in increased drag on the aircraft.”
The plane made an emergency landing in muskeg on the K’atl’odeeche First Nation’s land, an estimated 6.5 kilometres southeast of the airport.
Details of flight, engine failure
Two crew were onboard the plane when it took off from the airport at 7:41am the report reads, with the captain flying the aircraft and the first officer assisting.
As the plane was flying to cruising altitude, the report stated a decrease in oil pressure was observed on the left engine. Shortly after, “rising cylinder head temperature and oil temperature indications” were observed on the same engine. The pilot then directed the first officer to request a return to the Hay River airport.
As the crew began to prepare for approach, they observed smoke and oil, as well as “abnormal sounds” coming from the left engine. The crew shut down the left engine and feathered the propeller.
At 7:48am, seven minutes after takeoff, the crew declared a mayday emergency. Mayday, the report states, is a distress signal that indicates “imminent and grave danger and means that immediate assistance is requested.” The crew completed a descent checklist but were unable to complete an approach checklist, including the landing briefing, due to the “escalating emergency.”
The first officer then saw the landing gear down gauge had zero hydraulic pressure. He mentioned this to the captain, who then directed the first officer to “prep the gear.” The first officer then extended the landing gear. The report states the captain “did not expect (this) because the aircraft had not started its final approach and the airport had not been visually acquired.”
During the approach, the plane’s airspeed decreased and the “flight control response became sluggish.” At this point, around 7:57am, the captain directed the first officer to raise the landing gear.
At 7:59am the crew heard “abnormal sounds and felt vibrations” from the right engine. To keep the plane’s altitude, the crew increased the right engine’s power to “maximum takeoff power.” This had no effect.
The crew then prepared for an emergency landing with the landing gear up.
A photo of the DC-3 after its emergency landing May 3. Photo: TSB
The plane landed at 8:01am in muskeg on the K’atl’odeeche First Nation, 6.5 kilometres southeast of the Hay River airport.
Both crew evacuated, the first officer first then the captain exited after they had secured the right engine and aircraft systems. Both were uninjured.
At 11:14am, first responders arrived at the site.
The report states both crew were qualified to fly – having the valid licences and flying hours. Fatigue was not a factor, the report confirmed. The aircraft itself was also certified and maintained according to regulations, and the weight and balance were within allowed limits.
Because the investigation was limited, investigators didn’t look into the cause of the oil discharge that led the left engine to be shut down. The source of the “abnormal sounds” from the right engine was also not identified.
The report stated that speed and altitude during the emergency landing couldn’t be maintained, “primarily because of the increased drag when the landing gear was extended early in the approach.”
The report also highlighted the importance of following standard operating procedures and using “standard phraseology” and being disciplined with checklists during emergency landings. “Those are the key takeaways and lessons learned from this accident,” Adam said.
Buffalo, which could not be immediately reached for comment, is known across the Northwest Territories and beyond for its use of Douglas DC-3 planes.
The Yellowknife-based airline’s fame, driven by its own TV show – Ice Pilots NWT – is based on its dedication to an iconic fleet of DC-3 aircraft, each built more than 70 years ago.
The engine failure in May followed a year of an unusual number of aviation incidents. Those incidents included three fatalities when an aircraft crashed at Little Doctor Lake outside Fort Simpson, and the loss of two lives when an Air Tindi aircraft came down in January.
Over a broader span of time, statistics suggest the NWT is dealing with fewer such incidents year on year.
Between 19 and 31 reportable incidents have taken place in the territory over each year of the past decade.
Ollie Williams contributed reporting.