The inventor of the black box was told to drop the idea

> Interestingly, modern flight data recorders are required to have an underwater locator beacon that pulses once per second at 37.5 kilohertz for 30 days and is supposed to be detectable at depths of at least 14,000 feet (4,267 meters). But they don’t have comparable beacons for crashes on land.

After Japan Airlines Flight 123, that is shocking to me.

From TFA: "civil authorities said that “Dr Warren’s instrument has little immediate direct use in civil aircraft.” The Royal Australian Air Force likewise decided that “such a device is not required—the recorder would yield more expletives than explanations.”

Well. No. Multiple air crashes across the world relied on recordings as a key part of their investigation. Especially when a plane lands in the Hudson, just to name one example.

This is very telling:

"Most damning was the Federation of Air Pilots, which declared that the device would be like “a spy flying alongside—no plane would take off in Australia with Big Brother listening.”

History wasn't kind here either. Just try and take off in a jet from a commercial airliner without the various safety equipment installed. The insurance companies alone will try to eat you alive, let alone every other agency.

There's definitely a repeating theme around safety equipment and authority/authority figures. The ridicule at the start is definitely a common starting point. Seat belts and air bags were both ridiculous inventions. Then they weren't. Then they became required.

Quote from elsewhere and not necessarily about flight recorders: "It has been said that any new idea must pass through three stages. First, it is ridiculed; second, it is subject to argument: third, it is accepted. The safety idea has reached the final stage. It is accepted." -- Earl B. Morgan, journal of Safety Engineering, 1917

Well, they do: https://en.wikipedia.org/wiki/Emergency_position-indicating_...

But the reason you need underwater beacons in particular is that the water absorbs RF signals, so you'll actually use acoustic beacons underwater. Such a device would be useless above the water since air is so much less dense.