Not passenger airliners though. The most common passenger aircraft in active service shares the fuselage dimensions with the Boeing 707 which first saw service in the 1950s, but there aren't any 707s left in regular civil service.
Commercial aircraft rarely continue in passenger service beyond 25 years, never mind 65, and the maintenance requirements as well as the fuel bill means it doesn't make financial sense to try.
Is this true? Do you have a source? I have a hard time believing that lots of planes flying today are from the 1950s. That's 60-70 years ago. I did some searching but didn't find anything that would indicate there are any commercial aircraft that old still flying, much less lots - but if you have a source I'm curious about it. Thanks!
Edit: A google image search for '1950s airplanes' shows me very weird-looking planes that don't much resemble what we have today, in my experience. I now disagree with OP too, I don't think there has been nearly as much stagnation in airplane design and flight over the last 70 years as is indicated in these comments.
As the OP said designs, it would be true that many of those designs are still flying today. The 727 and 737 are derivatives of the 707 and the 757 isn't far off. Just different engine/gear/wing/length configurations.
New 737's may have more composites and more modern manufacturing techniques but it's not any radical departure.
For General Aviation, there are tens of thousands of planes from the 50's and 60's still around and the engines they use (Lycoming/Continental) are still based on designs from the 50s with modernized metallurgy, valves and fuel injection.
Yup. Even the fuel injection (in most cases) is based on 1950's designs though.
Incidentally, aero engine makers were playing around with direct injection, electrically controlled turbo waste gates and turbo-compounding at the beginning of WWII.
There are _plenty_ being used as freighters. Take the DC-3. First flight in 1935. Produced until 1942 (1950 in the URSS). Still in operation.
However, the 737 design is from 1968. Is that better?
In general aviation, there are lots of planes flying from that time. In flight schools you'll see a bunch of Cessna 150s, first flight in 1957. Thousands of aircraft still operational from that era, even some from the WW2 era (Ercoupe)
In the military, we have the B-52. From 1955. It was only produced from 1952 to 1962. Expected retirement is sometime in 2050, maybe later. That's a full century of service.
Planes are expensive. They are expected to be in service for many decades. Maintenance keeps them working almost indefinitely (even more so if they are not pressurized).
Airlines will only retire them when there are other, more economically viable, options(which sometimes includes new models of essentially the same airframe).
It might be true for GA, there's a lot of stuff from the 60s still around, but not for commercial aircraft. The average fleet age in NA is 14 years old. [1]
> A google image search for '1950s airplanes' shows me very weird-looking planes that don't much resemble what we have today
I'd be curious what you found. The Boeing 707 first flew in 1957, and it uses essentially the same configuration as airliners today (with some evolutionary improvements).
Commercial aircraft rarely continue in passenger service beyond 25 years, never mind 65, and the maintenance requirements as well as the fuel bill means it doesn't make financial sense to try.