No matter the size, the word is redundancy.

And Saturday (the day before yesterday?) I posted a photo on the page of a magnet system and its current distribution on the spark plugs, if you look closely at the same photo below, there is only one word, redundancy, present in aviation since the C152 ( a small aircraft), even the giant of the air An-225, even the most recent A380 already with Fly-By-Wire. Speaking of smaller aircraft, some of the redundancy systems in these aircraft are mainly concentrated in the powertrain, it is possible to observe, for example, the use of 2 magnetos and 2 spark plugs per cylinder. In a conventional car, a generator is used to recharge the battery, and only 1 spark plug per cylinder. But…. What's that for Peter? Well, only those who were on the road and the car's alternator starts to fail, know what good despair is, if on the road, with the possibility of a tow truck, we are already worried, imagine flying at 6000 ft in the air, in the case of my city (BrasÃlia) about 3000 ft from the ground. Â The magneto of an aircraft is not as modern a system as an alternator, but it is an independent and double system, already well tested and "reliable", this double system allows it to have the independent command of 2 spark plugs in the cylinder, so, if a magnet fails mid-flight and you can't fire it again, at least the mixture will still burn and you can switch to a closer airport.

Saw? the engine is of an old design but is relatively safe, besides, direct fuel injection, no “flooded” carburetor, ice formation, nothing like that.

Other point…. Important navigation instruments for the flight are repeated, as seen in this photo of the Cessna 340 (piston twin engine). And even the aircraft having an advanced cockpit system, like the ones with G1000. It repeats the same story of the large aircraft, essential instruments are also available in duplicate. See image below.

One more point, these aircraft usually have two radios, the good part is that the manufacturer could help with the reduction of costs and install a single antenna for the 2 equipment, but no, it has two, one for each radio, so if If an antenna fails or suffers from shadowing, you will have another one to use to communicate with ground control.