Now is a really good time to buy a helicopter

There's a reason aviation is many times safer than driving and an expensive field to play in. It came slowly though.

An old engine or airframe means they're well understood and don't trigger need for re-certifying. Every time an issue is found or production improvement is made it'll show up in EASA or FAA revised certification, maintenance schedules, time between checks, or even how you're allowed to operate it. Every identified accident cause filters into the system similarly.

A famous case came when jet liners were new, in the early 50s. The ground breaking DH Comet, and the world's first jetliner, was mysteriously falling out of the sky [1] with loss of all on board after around a year in service. That was when the world learned about metal fatigue in airframes and stress points. If it hadn't been DH it would have happened to Boeing or someone else [2].

The legacy was such that DH lost commercial opportunity for half a decade, and the world started along the track to a recognisably modern accident investigation and aircraft certification regime. Histories of that period in aviation are fascinating as it was also a particularly vibrant period as all the wartime progress was applied to lots of new designs of civil aircraft.

I'm not sure the thresholds differentiating between "it's a new engine now, full prototype testing and certification please", and the aviation equivalent of a revision note, but it seems incredibly low. Those Lycoming engines don't even put out a few more bhp than they did when newly designed back in 1950-something. A simple improvement in say carburettor design that would see a car maker just add the change doesn't happen easily in aviation. That's so some vanishingly rare circumstance doesn't cause it to fail in service with associated loss of life.

I dread to think what GA or Transport certification runs in at, but plenty have gone bust trying to make better GA planes or engines. Microlight, Light Sport and homebuilt (lightly certified) sectors have dozens of interesting weird designs and ideas, and experiments with new materials.

Even with all that mistakes are made, and people die, especially with new designs. The deaths stop much more quickly than in many other fields.

When a helicopter like a Super Puma, favourite of offshore operators, a 40 year old relatively simple airframe and engine has a $15m price tag faster progress becomes prohibitive. It's the aviation equivalent of a minibus. Just it's a very safe minibus with bookshelves full of accident history and safety revisions.

[1] https://en.wikipedia.org/wiki/De_Havilland_Comet [2] https://en.wikipedia.org/wiki/De_Havilland_Comet#Legacy (relevant section)

I half agree. You are correct that cars will eventually wear out, but not in 150,000 miles. Most cars today can go over 300,000 miles with basic maintenance.

The original post stated the car needed $3000 work of work, which seems reasonable. If he had put that money into the car that repair would be good for another 150,000 miles - before he does it again. Now we have to assume another $3,000 (number pulled out of me head, but it seems reasonable) in other maintenance alone the way. So for $6,000 more he could have a car with 300,000 miles on it.

What did the new car cost? If we assume that he got the full $4,000 value on trade in (seems unlikely, but dealers often will not consider overdue maintenance in trade in value) plus the $3,000 he needed to pay, plus the $3,000 that the old car would need in maintenance, minus $1,000 for maintenance on the new car we can suggest that $10,000 comes off that price.

Did he make a bad decision? You need to decide which of my numbers above are valid before you can answer it. It is quite likely that buying a used off-lease car with 30,000 miles on it and trading it in after 100,000 miles is probably the cheapest option in the current market.

BTW, the dealer taking the trade-in above is not stupid. He isn't going to fix the car. He is going to ship it to Mexico, sell it for $4,200 with the note that it needs some work done. The buyer in Mexico has just saved up $4,500 for a car (this took a while) and he will do the work himself. (Even if he paid someone to do the work the cost would be much less than our $3,000 figure above)

Avionics and engines are somewhat standardized "bricks", though.

Weight and balance is critical for airplanes. You can design the bricks, but you can't stick them together in any combination because a brick that will hold the tail wings for a 400 passenger plane is too heavy for a 100 passenger plane: the plane will not balance right and always be in nose up stall.

Also, there are not enough airplanes made. Even if the bricks idea can work, we still wouldn't make enough to give it significant enough economics of scale.