Lingering Effects

By Richard N. Aarons
Source: Business & Commercial Aviation
August 01, 2013

Flight operations in remote areas such as Canada's North–west Territories often are unconventional when compared with those in areas crisscrossed with busy airways, airports with precision approaches at both ends and border-to-border radar coverage. In the hinterlands it is not uncommon for the pilot of a scheduled commercial flight to manage all flight dispatch duties himself.

Such was the case at Air Tindi. The operator provides scheduled passenger and freight flights to and from its base in Yellowknife, Northwest Territories, using Cessna Caravan 208Bs under CAR Subpart 703. In addition, it's authorized to use single-engine aircraft for transportation of passengers under IFR and day and night VFR.

The company's self-dispatch system delegates operational control of flights to the pilot-in-command. In October 2011, crews were afforded latitude to conduct scheduled passenger operations under VFR. Under this system, the PIC was responsible for ensuring that appropriate documents including flight plans are prepared and filed prior to departure.

At 0800 on Oct. 4, 2011, a young Air Tindi pilot flew Cessna Caravan C-GATV on a regularly scheduled flight from Fort Simpson, Northwest Territories (CYFS) to Yellowknife as Air Tindi Flight 222. The VFR commercial flight arrived at 0919 without incident despite spotty marginal weather and a possible violation of airspace rules.

Fort Simpson weather at 0800 recorded visibility of 6 mi. in light rain and mist, broken clouds at 300 ft. and an overcast at 1,500 ft. The Caravan entered clouds shortly after takeoff and remained in clouds cruising at 3,900 ft. for most of the flight. Thus the trip was flown in IMC above the floor of controlled airspace at 2,200 ft. AGL in which an IFR clearance was required.

The next leg for this pilot was to depart Yellowknife with three passengers at 1100 for a regularly scheduled flight to Lutsel K'e located some 106 mi. due east. The company operations manual contained a published route with a minimum IFR altitude of 3,100 ft. ASL. This provided a minimum of 2,000 ft. of terrain clearance from the highest elevation of 1,100 ft., which was about 26 mi. west of Lutsel K'e. Most of the route lay in uncontrolled airspace, and an ATC clearance was not required. The airport was served by an RNAV instrument approach with a minimum straight-in LNAV descent altitude of 1,160 ft. ASL, or 567 ft. AGL. It was left to the pilot to decide whether to go VFR or file IFR.

The Yellowknife-Lutsel K'e region that day was under the influence of a trough of warm air aloft. The system generated overcast layers from 2,000 to 4,000 ft. ASL with tops at 24,000 ft. ASL. Scattered altocumulus castellanus topped at 22,000 ft. ASL. Predicted localized visibilities were from 3 sm to more than 6 sm in light rain showers and mist, and patchy ceilings were from 800 to 1,500 ft. AGL. Moderate mixed icing was predicted above the freezing level at 5,000 ft. AGL.

The terminal forecast for Yellowknife, valid for 24 hr., from 0600 was available to the pilot before departure. For the period of the flight, the forecast called for wind, 120 deg. at 12 kt.; visibility, more than 6 sm in light rain; a few clouds at 600 ft. AGL and a broken cloud cover at 1,500 ft. agl. Occasionally, the visibility was to be 3 sm in light rain and mist, with clouds broken at 600 ft. AGL. A revised forecast, issued at 1102, predicted essentially the same conditions, with a temporary lower broken cloud height of 500 ft. AGL.

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