Aviation Investigation Report A98H0003

1.7.7  Weather Conditions during Descent

SR 111 would have encountered several layers of cloud during its descent, placing the aircraft in instrument meteorological conditions. (STI1-51) The first layer of cloud was broken to overcast based at 24 000 to 25 000 feet. The aircraft would have likely entered a second layer of cloud at around 16 000 feet. The base of this layer was approximately 12 000 feet over the Halifax International Airport, sloping down to 7 000 feet over the Halifax Shearwater Airport.

As SR 111 proceeded north of the Peggy's Cove area at 10 000 feet, it is likely the aircraft was near the base of a cloud layer and may have temporarily been clear of cloud with good night flight visibility. As SR 111 headed south toward the ocean and began descending, it is likely that it would have entered a second layer of cloud. It would have entered a third layer at approximately 5 000 feet, and exited the layer no lower than 1 500 feet. Below 1 500 feet, the flight visibility was reported to be good and was likely unobstructed by cloud with the possibility of some light precipitation and fog over the water. When SR 111 was tracking toward the ocean, it would likely have been dark over the sea because of the cloud cover, mist, and lack of surface lights.

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