THE
VINTAGE INSTRUCTOR DOUG STEWART
Winter Ops, Part II In last month’s article I addressed some special considerations for those of us pilots who choose to remain in cold climates. (What do I mean choose? I wasn’t aware of the fact that I had a choice!) So let me rephrase that: For those of us pilots who find ourselves in cold climates and choose to continue flying throughout the year, we have special considerations that pilots in warmer climes do not have to deal with. I discussed the issues of airframe contamination from ice, snow, and frost. I also talked about the need for preheating our airplanes. I ended the article by promising to write about the issues of engine starting in the wintertime in this article, so here goes. Another problem with winter operations is that of getting the engine started. If the engine has been sufficiently preheated, starting should rarely, if ever, be a problem. But there will be times when a preheat might not be possible. I know that I have a hard time getting going when I am cold and stiff, and the engines and instruments in our airplanes are no different. The technology of our aircraft ignition and induction systems is certainly a vintage technology. It often seems that it takes a certain combination of magic, metaphysics, and luck to get a reluctant airplane engine running. (And this is probably just as true when it is hot as it is when cold.) It sure is satisfying when one can find a technique that works. I am well aware that there are numerous techniques out there for
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getting a cold engine running. The one I’d like to describe has worked for me virtually all the time. As a flight instructor at the Great Barrington Airport in southwest Massachusetts, we taught the following technique for cold-weather starting of the entire line of Piper Cherokees that we flew. We would use this technique in temperatures as low as 8˚F without preheating. Below 8˚ we would preheat prior to using this technique. (I personally recommend preheating anytime the temperature is below 28˚F, but these were not my airplanes and that’s the way the owner of the FBO wanted it!) With one pilot in the aircraft, to ensure that the brake was set and that the ignition was off, with the key out of the switch, another person would pull the prop through (anywhere from 10-16 blades) while the pilot inside the aircraft stroked the primer anywhere from six to 10 times. The primer was left in the full out position. Then the carburetor was primed with the accelerator pump about four times, with the throttle left open about 1/4-inch. After ensuring that the prop was “clear” the engine was started. As the engine fired, the primer was then pushed all the way in and then locked. It never failed! There are, however, some cautions. 1. Anytime you are going to touch a propeller, treat it as if the magnetos were on. There is always the possibility that a p-lead might be broken and thus the engine could fire. If you are doing
this alone (priming, then pulling the prop, then priming some more, then pulling the prop some more) be absolutely sure that the brake is set! And even then, treat the prop as if the mags were hot. Remember that you will have an induction system filled with fuel, and if a mag is “hot” due to a broken p-lead or switch left on, then someone could get very seriously injured . . . or worse. 2. If you do not push the primer in when the engine “fires,” but leave it out, the engine will be running way too rich, as it sucks fuel through the primer system. It will typically quit, and if it is cold enough, you will probably “frost” a spark plug. If that happens, you’re done with the start attempt, and you’ll have to pull the frosted plug. 3. (And this applies any time you are priming with the primer system.) If you prime too much, the excess fuel will be “washing” the cylinder walls with fuel. There might not be sufficient lubrication left on the cylinder wall as the engine fires, and it will cause premature wear on rings and cylinders. 4. If you overprime the carburetor with the accelerator pump, you run a great risk of an induction-system fire. Most of the engine fires I have witnessed were in the wintertime and a direct result of overpriming the carburetor. How will you know that you have a fire? You probably won’t, unless you notice people running across the ramp, wildly waving their arms and shouting. If you are good at lipreading, you might understand that they
are shouting “FIRE!” Some might be survive. There have been cases of pointing at the front of the cowling. pilots who did a fantastic job of There might even be someone run- landing an airplane in a forced ning with a fire extinguisher in his or landing, where no one was signifiher hands. If you suspect a fire, then cantly injured in the landing, but continue to crank the engine with then did not survive the walk out of the hope of sucking the fire into the the woods or the wait in the wilderinduction system; however, be pre- ness for help to arrive because they pared to exit the aircraft in a hurry. did not have the proper clothing to protect them. (As testament to Now I am not the fact that you Be aware that saying that one has might not know of a fire, I didn’t there are probably t o w e a r e n o u g h clothes so that he realize I had had or she is confused a fire in my PA-12 about as many with the “Michelin until the postflight Man.” I’m not sayinspection when techniques to ing that you necesI noticed that the sarily have to wear foam pre-cleaner engine starting, knee-high felt boots element was toast. (unless of course I had been oblivihot or cold, you’re in the back ous to the fire that had occurred on as there are pilots. seat of my Super Cruiser) while sitstart-up.) Be aware that there are probably ting at the controls of your airplane. about as many techniques to en- But I am saying that you should gine starting, hot or cold, as there have the proper types of clothing onare pilots. What works for one board the aircraft. Then if the worstmight not work for another. One case scenario does happen, you will thing that has to work for all of us be prepared. As we can see, winter flying ceris the recognition of the inherent safety issues involved. So whatever tainly does have its special considtechnique you find works for you, erations. For some pilots the effort is too great, and they sadly put be sure it is safe! The last thing I’d like to discuss their pride and joy away in winter about winter operations is how we hibernation, not to come out until dress for winter flight. I see many the sounds of geese flying north is pilots who show up at an FBO to heard. Other pilots head south with go flying dressed in not much more those same geese when they are than what is required for a cursory seen in their southerly migration. And then there are those of us walk around the airplane. They have come from a warm home to a who choose to deal with the extra prestarted car that has warmed up work and effort of flying in a cold its interior. At the airport the pre- northern climate. We are aware flight is conducted (sometimes in of the joys and exhilaration that a heated hangar) in a rather quick come from the increased perforfashion, and then just as quickly mance gained in the frigid air; we they get in the cockpit, fire up the are astounded by the breathtaking engine, and begin to warm up the vistas that are now seen, no longer hidden by the summer’s haze. cockpit as the engine warms up. The clothes they have on are We just have to be cognizant of the sufficient for everything that they increased risk of winter flight, and have done so far. And if the flight with that awareness we are able to is uneventful their clothing is still safely fly throughout the winter. adequate. But in the worst-case Wherever you may be, whether in scenario of a forced landing in in- a warm or a cold climate, may your hospitable terrain, they might not winter be GREAT!
VAA NEWS continued from page 2 low us to assist future leaders of the aviation community.” Complete information, including online registration, for the EAA scholarship program is available at www.eaa.org/education/scholarships. There is no charge to apply. Scholarships are open to all EAA members or students recommended by a current EAA member. EAA also welcomes additional support for its scholarship program, which has made a difference in the lives of hundreds of young people over the past 20 years. Contact EAA’s Development Office at 800-236-1025 for more information.
Order Your 2005 Sun ’n Fun Tickets Online Are you ready for Sun ’n Fun 2005? Now you can conveniently purchase your tickets online at the Sun ’n Fun website, www.sun-n-fun.org/tickets. As always, EAA and Florida Air Museum members get the best discount on registration fees. Non-members and the general public can also order online for this great April event in Lakeland, Florida. For more information, send an e-mail to fly-info@sun-n-fun.org.
‘SportAir’ Returns to Canada in 2005 Building on the tremendous success from the first EAA SportAir Workshop conducted in Canada last year, EAA SportAir Workshops will offer a full session of aircraft-building classes in Calgary, Alberta, on April 2 and 3. Jack Dueck, member of the EAA Canadian and EAA Homebuilt Aircraft councils, will host the workshop. Jack is an EAA SportAir instructor and will teach the sheet metal course. Other courses offered include composites, fabric covering, and gas welding. We had to turn away some folks last year, so if you’re interested in attending this workshop, visit the SportAir Workshops website, www. sportair.org, or call 800-967-5746 to reserve your spot today.
VINTAGE AIRPLANE 27