Pilot Debrief

DIAMOND DA-40 near Allagash, ME — 2011-03-07

Final reportERA11FA182
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Date
2011-03-07
Location
Allagash, ME, USA
Aircraft
DIAMOND DA-40
Registration
CGPDO
Category
Airplane
Highest injury
Fatal
Fatalities
1
Phase of flight
Descent

Probable cause

The pilot's inadvertent encounter with icing conditions, which resulted in an aerodynamic stall and loss of control. Contributing was the pilots’ inadequate preflight weather planning.

Contributing factors

Contributing was the pilots’ inadequate preflight weather planning.

NTSB narrative

On the day of the flight, the pilot called the London International Airport (YXU), London, Canada, Flight Service Station (FSS) to file a flight plan. When asked by the FSS if he wanted a weather briefing or Notices to Airmen (NOTAMs) the pilot declined. According to the FSS personnel, the pilot did not receive the vital weather information that called for icing along the route of flight. Two pilot reports were documented before the accident time with moderate icing conditions reported. According to the pilot-in-command (PIC), he and the pilot-rated passenger had reviewed the weather from computer sources. The PIC determined that an en route area of low pressure would have prevented them from reaching their final destination that day. The PIC noted that the low pressure area would be moving into their current area, Halifax, the following day, so he and the passenger decided to depart Halifax for Saint John, New Brunswick, where they would stay until the weather associated with the front had passed. The flight departed and reached a cruising altitude of 6,000 feet. During the flight, the passenger advised the PIC that ice had formed on the left wing, and the PIC observed the same on the right wing. The PIC described the accumulation as no thicker than a nickel at that point. The PIC requested a lower altitude, and a Montreal air traffic controller authorized a descent to 5,200 feet. The PIC told the controller that they were still experiencing icing and needed to descend to a lower altitude. During the descent, the PIC recalled that the airplane experienced the most ice he had ever seen in his life and that the canopy had completely frozen over. He described the ice as being as large as a house brick on the leading edge, extending back on the wing for 1 foot, and about 1 or 2 inches thick on the wing. The pilot observed that the airspeed was 84 knots and the airplane was buffeting in straight and level flight with full power. Ice continued to accumulate on the airplane, and the PIC advised the passenger to start looking for somewhere to land. The pilot estimated that they were about 1,000 feet above ground level while the airplane continued buffeting. The next thing that the PIC remembered was waking up in the airplane, next to the pilot-rated passenger, with no recollection of how long he was unconscious. Examination of the airplane revealed no evidence of a preimpact mechanical malfunction. Based on weather conditions, the airplane encountered severe icing conditions.

Analysis

Primary failure mode
Spatial disorientation
First missed decision gate
Pilot should have turned back or landed before encountering severe icing.

NTSB coding

Evidence available

  • Photos
  • 28 docket documents
View NTSB final reportView NTSB docket

Docket documents28

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