The unstallable plane that stalled • Hacker News Board

Re: The unstallable plane that stalled

#181

Post by ambicapter » Tue, Apr 30, 2024, 11:35 PM UTC

tim333 wrote: post #157

buildsjets wrote: post #94

I've been involved in general aviation since the late 1970s, currently commercial/twin/instrument rated, have a degree in aerospace engineering, and do what my username says for a living. So I know airplanes, and why they do the things they do. But an appreciation for what is physically occurring during a stall, how the resulting balance of forces influence the aircraft handling during a stall and recovery, and why t…

Yeah I got a PPL and there was no mention in my training of stuff like that which happened to this plane. That said I'm surprised it behaved like that - turning dramatically to one side on stalling. All planes I've flown, model aircraft that I've built and paper darts just lose lift when they stall rather than yawing to one side. It seems there was something off with the aerodynamics of that plane.

Maybe the higher torque of the propeller?

Re: The unstallable plane that stalled

#182

Post by onetimeuse92304 » Wed, May 01, 2024, 8:47 AM UTC

As an amateur sailor, the idea that they discussed wearing lifejackets INSIDE the craft seems completely stupid. One of first things any sailor learns is that you do not wear lifejackets inside the craft.

It is not possible to swim through submerged openings (windows, doors) in a lifejackets as it is simply pulling you up and preventing you from diving down.

A lifejacket is also very bulky and offers a lot of opportunity for snagging on equipment.

If they had lifejackets on, probably nobody would save themselves unless they were able to untie themselves in time.

Just imagine the hell of trying to free yourself from the snagged seat belt WHILE in a life jacket that constricts all your movements and makes reaching your legs very difficult and pulls you constantly up putting continuous force on whatever snagged on your feet.

Re: The unstallable plane that stalled

#183

Post by ExoticPearTree » Wed, May 08, 2024, 9:19 AM UTC

jnsaff2 wrote: post #164

ExoticPearTree wrote: post #158

Earlier quoted context omitted.

> Stall speed is an approximation. It's baffling that GA aircraft don't have one of the most safety-critical measurements: AOA. All aircraft equipped with a six pack, you have an artificial horizon indicator which can tell you what is your angle of attack. And Cessna's have them in all planes, even 50-60 years old ones.

The angle of attack is the angle between the chord line of the wing and the oncoming air (or relative wind). This is distinct from what the artificial horizon measures. The artificial horizon is concerned with the aircraft's orientation relative to the gravitational pull of the Earth, indicating whether the nose of the aircraft is above or below the horizon and how much the wings are tilted relative to the horizon. A…

> Artificial horizon is not a reliable indicator of angle of attack.

Keyword being "reliable", but it is pretty close to it. That's how you get to fly safely through clouds using only an artificial horizon indicator.