Whomst pong’d?
Yes, magento-type ignition is still used in aviation due to the simplicity and self-contained nature of it. You can suffer a complete electrical bus failure and still run your engine in a piston-engine aircraft, something that you notably cannot do in your personal vehicle. They’re not inherently more reliable than a modern electronic ignition, though, usually requiring major inspection and maintenance every 500 hours or so. That’s anywhere from about once or twice a year on a flight school bird to every five years or so on someone’s “I fly just enough to stay current” bird.
There’s a growing movement to electronic ignition with an integrated generator driven off the magneto drive gear, but it’s still restricted to Experimental/Amateur Build aircraft at this time.
Dual redundant magnetos do provide added safety, but also provide more uniform combustion and improved efficiency. Airplane piston engines use relatively large cylinders and low RPMs, so getting a proper burn is hard with one spark plug. Two plugs solves that, and provides redundancy. Win/win.
As for APUs… they actually predate the practical jet engine by several years. Famous example of that is the B-29, which had a small piston engined APU aboard to help provide enough electricity to start the mighty R-3350 engines.
Jet engines have usually used some form of external power source for starting basically from their inception. The famous Me-262, for example, had a direct-drive APU in the intake nose cone: a little 2-stroke diesel engine with a pull starter which spun the engine up to the self-accelerating point. Electric starters were used for smaller engines basically from the outset, but they typically used an external power supply like a Ground Power Unit (GPU) to drive the starter. Batteries just couldn’t provide enough current for the long spool times required to start a turbine engine, and the only reason they can do it on smaller jets today is improved efficiency on the starter motors and the two-spool design of modern engines reducing the rotating mass the starter needs to turn. Even then, most midsize business jets and up will feature a small gas turbine APU, typically a Honeywell unit, which provides extra electricity to assist the battery/batteries during the start.
Larger engines, or smaller ones where weight is a constraint, will use a high volume, low pressure (~40 psi) air turbine starter to spool the engine. This is the kind that would have been used in 2nd and 3rd generation combat jets, due to the lighter weight and simplicity, although those were typically externally powered by a GPU, often referred to as a “huffer cart”. A variety of these existed, and still exist today. You’ll occasionally see them in use at airports when they have an INOP APU.
On that note, the APU on larger aircraft primarily provides the large volumes of compressed air needed to spool up an airliner engine, but also provide electrical power, and occasionally hydraulic power via a direct pump, although that is rare.
Starting an engine with the jet blast from another engine is definitely in the category of “well, we’re screwed if we don’t get an engine started!”, and is not something taught in training. The folks involved probably used a variation of the in-air start approach, but you probably have to watch your turbine temps really closely… I can see that turning into a hot start really quickly.
Cartridge starters are basically a small solid rocket motor firing into a really durable starter turbine to accelerate the engine to self-accelerate speed in single-digit seconds instead of the more typical 15-20 seconds. I can’t recall any civilian designs that used it. There’s a piston engine equivalent, the shotgun starter, which may have seen some limited applications in civilian designs but again was mostly military.
