Page 24 - February 2015 Volume 19 Number 2

22 • TWIN & TURBINE FEBRUARY 2015From The Flight Deck by Kevin R. DingmanBaby, It’s Cold Outside!from Lycoming and the Duke Flyers Association regarding cold weather starting procedures. The Duke had been parked outside at the DEN Centennial airport overnight where the OAT had been around 20 degrees Fahrenheit; granted, this is a smidgeon below 50. When the left starter was engaged (the engine closest to the battery), it responded with an undeniable “I don’t think so”. While the Duke enjoyed two hours in a heated hanger, the PIC enjoyed some light reading in the POH about GPU-assisted starting procedures. The engines started just fine after that, but this trip convinced me to pick a number well above freezing to begin preheat procedures. This was also the trip in which I had a very memorable GA experience.We all know that “to con” or “conning”, means to make contrails; non-pilots call them vapor trails. Contrails can be produced during high humidity if an airplane is in a configuration/attitude of high AOA, such as during landing. More often, we associate contrails with an aircraft at altitude. The white trails are generated by the moisture/ temperature reaction of engine exhaust to the cold air. On the flight home from DEN that chilly morning, the OAT at FL 220 was minus 60 Centigrade. The Lycomings in the Duke were making contrails – cons from piston engines! It was reminiscent of WWII bombers and was an inspiring sight; after the two seconds it took to realize that they were not on fire, that is.In order to convince our airplanes to go flying when it’s cold on the ground, there are things to do before the weather turns cold, and after we arrive at a cold hangar, and both during and after the starting sequence. Installing oil cooler baffles, filling tires and struts with nitrogen, use of multi-grade or low- viscosity lubricants, setting the hangar temperature and removing water from the airframe: all of these fall under the before-it-gets-It’s winter in this hemisphere, which means it’s colder – colder than when it’s not winter. And although winter is a fine time to add a nip of something to your cocoa and wrap yourself in an afghan near a crackling fireplace, it’s not such a fine time for your airplane out on the ramp.This article is about the issues our flying machines face during winter ground operations. It’s about being nice to your battery (ies), motor(s), furnishings and equipment when it’s cold outside by using the proper gasses, liquids, pre-heating, and warm-up techniques. In other words: how to convince your airplane to go flying when it doesn’t want to go.And before you turbine-powered pilots peel off to peep at Dave’s article on the posterior page of this publication, postulating that the preponderance of pearls in this pilot’s column are probably pointed at piston-powerplant-powered- planes, pa-fa and au contraire, mon capitaine. There will be plenty of potentially pertinent pearls presented to you as well, so please be polite and persevere.Half-NakedWe all become acclimated to the temperature of our environment, and therefore have different perceptions of what temperature feels cold. The Mayo Clinic in RST is a common destination for Wings of Mercy trips, and at my Part-121 jobwe fly to MSP quite often. The hardy souls in these two locales strip-down if the Hg climbs to 30, and are in shorts by 40 degrees. Bless their half-naked, thick-skinned hearts. In some parts of the country, 50 degrees Fahrenheit is cold.If it’s 50 in February where I live, we don short sleeve shirts, cartwheel out to the deck and fire up the Weber. The only way to know the temperatures at which our aerospace vehicles feel the cold is to follow the manufacturer’s recommendations, learn from our experiences and listen to the tales of old-timers. Here, in the warm surrounds of your home, office, FBO or cockpit, we will explore a splattering of each.In the Duke community, 50 degrees and lower is when we pre- heat our 380-hp Lycomings. I’ve often received raised eyebrows or a shaking head when another pilot sees the torpedo heaters blowing up through the cowl flaps into the motors when the temperature drops below 50. A waste of time, they say – it’s unnecessary. Those MSP folks would think it’s toasty at 50 and pilots from TPA would say it’s chilly. We need to select a temperature to pre-heat motors, interiors and avionics. Fifty degrees seems reasonable.I Don’t Think SoA few years ago I tried to get away with ignoring the recommendations