David writes...

We sure missed Jim this morning.  He has been a great part of this trip.  

Earl and I slept in a bit and left around noon as the rain and clouds that came in during the night started to dissipate.   We filed our flight plans to Whitehorse and headed southeast.  We made a quick stop at Northway for fuel and continued down the highway back into Canada.  As we few most of this leg with clouds above us last week, we realized how much we missed with the Wrangall and Saint Elias Mountains to the south.  We landed in Whitehorse and cleared customs again--a simple phone call.

As a side note, we were impressed with how friendly, helpful and efficient the Canadians were throughout our trip.  As a pilot using their system, it was very easy.  

Earl landed after I did in Whitehorse.  I noticed that his plane sounded a little throaty while taxiing, but was tired and dismissed it.  Unfortunately, Earl said that about 50 miles out, he started loosing some power.  Going though his checks, he realized that the right magneto was not firing.  Thankfully, the left one was fine and he made it into Whitehorse okay.

For those of you not familiar with small plane engines, the technology is really quite basic and has essentially remained the same for decades.  Most small aircraft engines have two spark plugs on each cylinder.  Each set of spark plugs is wired independently and receive their electricity from a different magneto (there being two magnetos on each engine).  The Magnetos are driven by the engine.  This redundancy offers a margin of safety in the event of electrical failure.   For example, in a car, if your electrical system fails, your car will eventually stop running.   In an airplane, your entire electrical system can fail and your engine keeps running like nothing ever happened.   You can keep flying, however, it does become more challenging as you don't have any radios or navigation equipment.  If you are flying in the clouds, this is a real emergency.  But if you are flying in the middle of a beautiful day, you just keep going.  

Early planes didn't have electrical systems at all.  Remember the old footage of someone standing in front of the plane and hand propping (pulling on the propeller) to start the engine.  You can do that with most small planes today as well.   Actually, some of the bush pilots take the electrical systems out of their planes as they add too much weight that they'd prefer to have to haul supplies.  They just hand prop the plane each time they start it.

Anyway, one of Earl's magnetos had something wrong with it, so in the morning we need to find a mechanic.