I’m going to add a list of things that I think are going to be cool to see:
- New engine options. Previously getting an engine certified was a big expense, so there wasn’t a lot of advancement. Now I think that higher performing Light Sport aircraft can be made with non-certified engines or components. All electronic ignitions, variable valve timing, electronic fuel injection, it’s all on the table now, and it gets to exist in a factory manufactured plane, not just experimentals.
- New avionics. The light sport category got to put some neat digital avionics in their panels because they weren’t certified. They had portable ADS-B transmitters that were legal. These options will now be open to faster planes too.
- Importing light sports from around the world. Lots of European light sport planes couldn’t be imported in the past because they weren’t certified but were too fast for American light sport rules. Now a lot of them will be able to be imported as soon as the rules allow.
- Cheaper complex trainers. Allowing variable pitch props and retractable gear in the light sport category will hopefully mean there will be a plane that comes along that allows you to build time in the complex category without spending the money that usually comes with these types of planes.
- there’s probably a bunch of other things we’ll see that I haven’t thought of, and I am curious to see whatever that is as well.
I really want to believe that MOSAIC will usher in a revolution of safe, affordable airplanes, but I'm not holding my breath. A lot of the stuff you mention has existed for decades in experimental aviation (electronic ignition, EFI/FADEC, non-TSO avionics, the ability to import factory-assembled but otherwise non-certified light sport aircraft...), and none of them seem to offer compelling cost, performance, and safety advantages over legacy systems.
My cold take is that the only significant, short-term effect will be slightly lowered training standards for low-to-moderate-performance aircraft. It's unclear that this will have any practical effects, since personal airplanes will remain prohibitively expensive to own and operate for the vast majority of us.
Garmin charges an extra $1275 for their G5 instrument if you’re putting it in a certified aircraft vs a light sport. $1850 vs $3095. I’d call that a compelling cost advantage.
FADEC means one less knob the pilot had to worry about in flight and one fewer item on the landing checklist. Probably not a massive performance difference, but I’ll call the sum of the marginal fuel efficiency and engine longevity gains along with the additional safety reduced cognitive load a compelling advantage overall.
Cheaper, modern three axis autopilots are compelling. Repeat this exercise twenty more times with areas all over an airplane and you make a huge difference. Cheap planes aren’t going to swamp the market overnight, just like most of the original LSAs were over $100k when they first came out. But a $100k LSA sure was cheaper than a new SR20 or C172. But they trickled in, and now you can buy a few year old LSA at a decent price. The new crop will start to trickle in over the years too and maybe I’ll be able to afford one when I’m at retirement age.
You’re right about the reduced training standards, but doing it with the old light sport pilot restrictions didn’t cause a massive increase in incidents, so maybe this won’t be that bad. If you fly around rural airports you’ve already been flying around sport pilots and people on BasicMed for several years, so you would have already seen the difference.
In the experimental homebuilt world, just the fact that you (the builder) can choose to equip your plane with < 50 year old technology is compelling. All those things OP mentioned involve trade-offs that the builder needs to consider, but I’d rather have the choice than not (which is the case for certified airplanes).
- New engine options. Previously getting an engine certified was a big expense, so there wasn’t a lot of advancement. Now I think that higher performing Light Sport aircraft can be made with non-certified engines or components. All electronic ignitions, variable valve timing, electronic fuel injection, it’s all on the table now, and it gets to exist in a factory manufactured plane, not just experimentals.
- New avionics. The light sport category got to put some neat digital avionics in their panels because they weren’t certified. They had portable ADS-B transmitters that were legal. These options will now be open to faster planes too.
- Importing light sports from around the world. Lots of European light sport planes couldn’t be imported in the past because they weren’t certified but were too fast for American light sport rules. Now a lot of them will be able to be imported as soon as the rules allow.
- Cheaper complex trainers. Allowing variable pitch props and retractable gear in the light sport category will hopefully mean there will be a plane that comes along that allows you to build time in the complex category without spending the money that usually comes with these types of planes.
- there’s probably a bunch of other things we’ll see that I haven’t thought of, and I am curious to see whatever that is as well.