October 2019 Safety Corner
With cold weather now upon us, here are some tips that are critical for safe flying and the safety of our Skyhawk Flying Club airplanes. Obviously, good decision-making skills are critical to any flight but it’s even more important in cold weather flying. Read over these hints and tips and store them in the back of your mind.
A cold start stresses the engine, the starter, and the battery. Engines should be preheated below 40 F˚, so it’s critical that you plug in the Tannis system after each flight and the blanket placed on and in front of the cowling for use by the next pilot. Remember, only atomized fuel can be made explosive. Cold fuel does not evaporate as well as warm fuel so more time is needed to create the starting mixture.
A cold start in the C-172 begins with two to three pumps of the primer. Lock the primer and wait a minute or two to allow the cold fuel to vaporize. As you begin to turn over the engine advance the throttle. In the Arrow, crack the throttle slightly and turn on the fuel boost pump. Advance the mixture full until you see movement on the fuel flow gauge, then retard. After the last annual, we’ve noticed that we’re not getting the gauge to move off the peg, so turn the pump on for a 5 second count and advance the throttle just a little more. This will indicate that the cylinders have been primed with enough fuel to start the engine. Once the engine fires up, turn the fuel pump off and then follow the checklist.
Cold Weather pre-flight checklist
- The club doesn’t buy them, but it wouldn’t hurt to purchase a new CO patch from in the cockpit if you are
taking a long cross country. These are inexpensive items that you can find in Sporty’s but it may save a life –
yours or possibly another member’s life. If you know you’re going to take a long X/C in any of the planes, it
wouldn’t hurt to examine the vent systems in detail.
- Make sure the Tannis and (if installed) the trickle charger have been plugged in before using
- For the cockpit, survival gear with survival clothing or blanket on a X/C is prudent.
- Check static and pitot for ice. Turn on the pitot switch to check for heat going to the pitot.
- Make sure quick-drains are actually draining.
- Remove ALL ice, snow and frost if you have to park the plane outside on a X/C to another airport. Work with
the local FBO on pre-heat options.
- Runway lengths, surface type and widths become critical. It’s not unusual to fly to an airport and find out that
the runway is ice covered, so give the FBO a call for a review. By calling ahead, it allows you to talk to someone
personally as to the exact conditions when you reach your destination.
Keep these additional pre-flight items and tips in mind
- Because of the cold, pilots have a tendency to rush through the preflight. Bundle up and grin and bear it, please.
- Look for fuel dye or discoloration as an indicator of fuel leaks.
- Keeping the tanks full keeps out moisture. The right tank in the Bonanza has been known to have a bunch of
water so take your time sumping. Super-cooled fuel can create ice crystals and a rough engine. Carb heat helps
this situation in the C-172.
- When checking the fuel strainer, remember that ice in fuel looks like floating dust.
- Prime 50% more than normal when it’s cold and 100% if really cold.
- Double check the pilot handbook’s recommendations for cold weather ops during your night before checklists.
- Let engine warm up until oil thins out and pressure is normal. Cold oil will be more viscous (thick).
- Hoses, flexible tubing and seals become brittle in cold so allowing the plane to warm up will be safer
- A cold battery will be weakened unless fully charged
- Control cables’ lubricants will congeal. Warming the engine will also help warm the cables.
- Don’t use anything that works on an automobile to remove ice because deicing fluids cause corrosion and
leave unpleasant residue.
- Confirm fuel selector is not frozen in one position.
- DO NOT DO MANUEVERS THAT REQUIRE LOW POWER SETTINGS (STALLS, SLOW FLIGHT,
ETC.) WHEN TEMPS ARE BELOW 15-20-DEGREES ‘F’. Many a pilot has found themselves with no power
after doing maneuvers in very cold weather with the throttle retarded.
- If going on a X/C, take the cowling blanket AND bring a 100 ft. long extension chord from home so you can
plug the Tannis in at the destination FBO. Many times, there are plugs outside near a hangar so working
something out with the FBO to park close and use the plug would be awesome!
- If you can’t plug in the Tannis or will not be at your destination very long, I would recommend taking the tow
bar and refrain from parking the cowling INTO THE WIND, which is standard at most FBOs. The engine will
cool slower and will be easier to start later – especially with the Arrow.
In case you didn’t know. . . .
- Thirty seconds of cranking = 50 hours flight time wear
- Electrical loads will be heavier.
- Don’t set parking brakes after heavy use of them – hot brakes will freeze solid. Let them cool first.
- Idle at a little higher than normal rpm to keep plugs from fouling and oil hot
- Normal engine temperatures are necessary to evaporate moisture in crankcase.
- Change tanks more often so that maximum fuel is available.
- If RPM rises when carburetor heat is applied it could mean that air filter is blocked
- Gyros will need to warm up and speed up, too. It’s not uncommon to see the AI cockeyed for a while.
- Use radios only after electrical system has run a few minutes.
- Keep in mind that braking on snow or ice may be poor to nil. You don’t have differential power like a twin-
engine plane to help keep you on the runway. If you land on ice, you’ll be at the mercy of mother nature and the
laws of physics. This is why it’s important to call your intended destination AND check NOTAMSs.
- Keep power up during descents and extend any drag that may be available. This will keep the engine warmer.
- Don’t use brakes until tires are on hard surface. Be prepared for ineffective braking. Touchdown areas of
runways are more slippery.
- If there is any slush on the runway, recycle the gear in the Arrow and Bonanza once you have lifted off. This
will help knock off the slush and keep the gear from freezing in the wheel wells.
- Ramp operations can cause ‘black ice’ problems for taxiing.
- Weather systems move more quickly in winter. Fast-moving winter systems create turbulence and hazardous
- STAY CLEAR OF ANY ICING CONDITIONS!!!
- Just remember that your performance on contaminated runways will be less.
- Reduce crosswind capability by 50% for snow and 75% for ice
- Just because no ice is forecast doesn’t mean there won’t be any. IF you find yourself picking up any
unforecasted ice, change your altitude. This is where preflight preparations are critical. Know where warmer air
is and where good VFR weather is. If it’s forecasted – DON’T GO.
- If you find yourself in it, descend through ice at lower speed but high rate of descent.
- Carburetor ice is far more likely to occur and cause an accident than is airframe icing. 51% of icing accidents
are caused by carburetor ice or induction system ice. The cause of this ice is the failure of the pilot to
ANTICIPATE the possibility of ice by applying full carburetor heat and alternate air. The fixed pitch plane will
develop a rough engine while the constant speed plane is going to show a drop in rpm. Under icing the C.H. will
increase the roughness of the engine. Leave it on. Use alternate air if available.
HOPE THIS HELPS!! KEVIN BRODERICK, SAFETY OFFICER, ATP, CFII