Wet on takeoff? Beware of low freezing levels.
Heading south for fun-'n'-sun, the Aztec pilot, en route from Calgary to Cabo San Luca, landed in Salt Lake City to refuel. Heavy wet snow was falling as he taxied in to the refuelling point, and quite a lot of the wet stuff accumulated on the airplane during his pit stop. The pilot carefully cleaned all of the snow off the wings and tail before taxiing out for takeoff. Even so, his efforts did not leave the surfaces clean and dry. A lot of moisture had seeped into the control hinges.
As he climbed into the colder air aloft, the moisture froze and so did his elevators. With dauntless skill and a lot of sweat, he successfully manoeuvred the Aztec back for a safe landing.
A Boeing 767-200 was cruising at flight level, en route from the west coast to Toronto, when the aileron control became abnormal under both autopilot and manual control. The crew diverted to the nearest suitable airport. During the approach, aileron control returned to normal, and the aircraft landed without incident.
The aircraft was inspected. No fault was found. The flight was continued to Toronto.
The aircraft had been parked outside overnight at the west-coast stop and had been exposed to heavy rain. All indications are that water had entered the aileron control system, which then froze at altitude, causing the jam. During the approach into warmer temperatures, the ice melted, leaving no evidence.
With clean wings, we still need to be aware of moisture when the mercury dips below the freezing mark immediately after takeoff.
The PA31 had had an unplanned encounter with a snowbank, damaging the nose gear. The pilot was ferrying the aircraft home, gear down, for repairs. On arrival at destination, after a smooth touchdown, the frozen right brake caused the tire to blow, and our unfortunate pilot had a second encounter with a snowbank.
Warm brakes + cold snow = moisture. If you dont dry the brakes, they are guaranteed to freeze later.
Two successive Bradley Air Services B727 arrivals at Iqaluit made the smart move last winter. The only available runway at Iqaluit is 18/36. The wind was 240· at 22 kt., gusting to 34 kt. The James Brake Index (JBI) coefficient was 0.34. Both captains decided to divert 160 mi. to Kuujjuaq, an expensive decision for the company. But had they attempted the landing, only to become curling rocks immediately after touchdown, the bent aluminum would have been a lot more expensive.
Beware of Hazards Off the Ice Strip
Overhead the frozen lake, the 185 pilot assessed the wind as moderate to strong and at 90· to the ploughed ice strip. He decided to land into the wind off the prepared strip.
Blowing snow and whiteout conditions made the approach extremely difficult. During the after-landing roll, the aircraft was severely damaged when it struck a snow ridge that the pilot could not see.
The 185 charter pilot departed in visual conditions and climbed to 400 ft. above ground level (AGL). Five miles later, he encountered whiteout conditions over a frozen lake. The instruments told him he was in a descending left turn. He didnt believe them because he could not feel the turn. When he finally realized that the instruments were telling the truth, it was too late. The aircraft struck the ice, tearing off the left wing. Fortunately, after all the parts came to a stop, he walked away unhurt.
Whiteout conditions mean IFR. Believe what your instruments tell you.
Originally Published: ASL 3/1997
Original Article: Winter Shorts