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There are a lot of 1950s and 1960s aircraft designs still flying. That was when smart people went into aircraft design, and it was the most productive period in aircraft design history, as everything went jet-powered. The B-52, the B-737, the B-747, the SR-71, and the Concorde are all from that period. (So are a lot of duds, of interest only to aviation historians.)

Ben Rich, former head of the Lockheed Skunk Works, once remarked that he'd worked on 30-some aircraft in his career, but today's engineer will be lucky to work on one.

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I worked on six aircraft by my mid-20s, if you count internships. I'm 31 now. Rich was more referring to sprawling military programs with legislative delays. You can change programs within a company, or change companies.

Also, you're kidding yourself if you think any a/c from the '50s is flying with all original parts. Like any machine, it can run indefinitely as long as you replace components. At my first company out of college, we were updating aircraft put into service in the '60s. We did new engineering to redesign parts, for example replacing an assembly of three primary components with a single CNC machined piece of aluminum. It just was not possible to fabricate the geometry with tools of that era. The new assy was simpler and stronger. Advances and upkeep like these are what keep old machines flying.

Not only would it be highly improbable, it would be highly illegal. The FAA mandates inspections and part replacements/engine rebuilds at certain hour intervals.

That said, here's a C130 that flew for 52 years: http://foxtrotalpha.jalopnik.com/usafs-oldest-c-130-hercules...

Engine manufacturers typically specify a TBO -- Time Before Overhaul, which is the number of hours in service an engine can run before it needs to be torn down, inspected, and overhauled according to the manufacturer's procedure.

For the most part, commercial operators must adhere to these recommended times, but aircraft operated under FAR Part 91 (roughly, those that aren't used for commercial transportation) aren't required to follow the TBO recommendation. You can run it as long as you want.

In practice, most operators do follow those guidelines. I've never heard of any engine doing much more than 2x the TBO before requiring major overhaul. And you'll often need various repairs to cylinders and engine accessories along the way.

Interestingly, manufacturers also specify calendar time limits on TBO, but private operators commonly ignore these. Lots of airplanes only fly 25 hours or so a year.

In the mid 60's and mid 70's, US manufactures were selling over 10,000 single engine piston aircraft a year. Last year, it was 685 single engine piston aircraft.

What's the explanation for the huge drop in sales? Those single engine airplanes are still around? Deregulation of the airlines has resulted in cheaper commercial air travel? More telecommuting? What?

I'm genuinely interested in the explanation.

Very good question. Planes used to be so much cheaper, too.

I'm not an expert, but from what I gather there was this issue where product liability law suits drove aircraft manufacturers out of business. Even Cessna went bankrupt and was sold to Textron, and production of even the Cessna 172 stopped for a decade or so in the mid 80's.

The General Aviation Revitalization Act was supposed to fix this, not sure how much it has (see link at end).

Would love to hear more about this. Regulation is clearly a huge factor.

By the way, as much as one can complain about the general aviation scene in the USA (regulation, FAA, ...), on a global level it's still paradise. In Europe it's more complicated and expensive and cumbersome, even though the EASA is slowly moving in the right direction as far as I can tell. In Asia, general aviation is nearly unheard of. Australia has some, though it's really too big :-) Interestingly, Africa has pockets, e.g. in the south (South Africa, Namibia) and east (Kenya).

https://en.wikipedia.org/wiki/General_Aviation_Revitalizatio...

There was a terrible "aviation winter" in the mid-80s with product liability concerns, economic issues (high interest rates), and a spike in fuel prices resulting in the bankruptcy of several manufacturers and other manufacturers stopping the manufacture of piston-powered airplanes entirely.

https://generalaviationnews.com/2015/05/31/analyzing-statist... has some decent (and short read) background on the overall trends.

To me, the more interesting question is "why were the 60s and 70s so good for GA?" De-regulation of airlines was probably one factor, but it can't be the only one.

I'm 45 and a pretty avid owner and pilot. For most airport activities (fly-ins, safety seminars, etc), I'm usually the youngest one in the room, often by a lot. I get the sense that wouldn't have been the case 50 years ago.

> To me, the more interesting question is "why were the 60s and 70s so good for GA?" De-regulation of airlines was probably one factor, but it can't be the only one.

Lots of WW2 pilots still alive and interested in flying in the 60s and 70s, maybe? I'm just speculating, but the population of flight-trained people in the country has probably not been higher than then.

I know a lot of veterans got pilot's certificates with the GI Bill education benefit, so that was probably part of it (in addition to conversion of military pilot experience into civilian certificates)

RE your last paragraph, I think cost is a HUGE factor preventing more young GA pilots. What's the cost to get a PPL these days? In the range of $5000-10000? And IIRC, the total operating cost per flight hour, even for something like a C-172, is north of $100?

Even as a young 30s software engineer with a comfortable salary and a PPL on my bucket list, it looks like a terrifyingly expensive hobby. The vast majority of people simply can't afford it.

PPL is probably on the high side of that range.

Local flight school rents their 172s for $135-150 (depending on airplane), and based on my ownership experience, they're not making fat margins on that.

expect $30,000 for PPL in Australia

I have no expertise here, so this is just speculation. But I am thinking that it got to a point where everyone who wanted and could afford a small plane had one, they could be kept flying forever, and there weren't any major improvements so no reason to buy a new one. Plus, as a comment above said, small planes used to start with a military contract, and the military was switching to jets so you didn't see that anymore.

One theory I have is WW2 and Korean Wars. Lot of young pilots hit their prime earning powers during the 60's and 70s' and bought up private planes.

Nowadays the interest is not there and the training cost is high. These WW2/Korean pilots got free training from the military.

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