The Airplane That Tried to Stall Itself | A Test Pilot Discovery

Hinzugefügt: 2026-05-07

[00:00:00]The airplane that tried to stall itself.

[00:00:04]There is an airplane I want to tell you about today that just didn't stall. It tried to stall itself. Now, think about that for a second. The pilot does everything right, steady pull, controlled approach to the stall, and suddenly the airplane helps you pull up even more.

[00:00:20]Not because you asked it to, but because the aerodynamics took over.

[00:00:25]And that's exactly what happened during the certification of the Airspeed A.57 Ambassador, a British aircraft.

[00:00:32]Now, this story comes from David P.

[00:00:34]Davies, one of the greatest test pilots of that era.

[00:00:38]And if you ever read his work, you know he had a way of explaining things that makes you stop and say, "Wait a minute.

[00:00:44]Airplanes can do that?"

[00:00:46]This was in the late '40s and the early 1950s. Certification then wasn't what it is today.

[00:00:54]There weren't layers of simulation and modeling like we have now. You found out what an airplane would do by going out and flying it.

[00:01:04]And sometimes the airplane taught you something.

[00:01:06]The Ambassador was a good airplane, twin engine, big, beautiful radial engines, pressurized cabin, flown by British European Airways as the Elizabethan class.

[00:01:19]It was comfortable, reliable, and well-liked.

[00:01:24]But like a lot of early post-war designs, it still had a few things to teach the engineers.

[00:01:30]Now, let's go into the stall testing.

[00:01:32]Picture yourself in the left seat.

[00:01:34]You're at altitude, power coming back.

[00:01:36]You start bringing the nose up, just like you've done thousands of time in any other aircraft.

[00:01:42]Everything feels normal. You add a little back pressure, and something subtle starts to happen.

[00:01:49]The airplane's pitching up, but it's pitching up a little more than you expected. You ease off slightly, and it doesn't quite respond the way you think it should. Now, that gets your attention.

[00:02:00]Here's what's going on.

[00:02:02]The elevator on the Ambassador was overbalanced. Now, in plain English, that means that the airflow over the elevator wasn't just helping you move it.

[00:02:12]It was helping it move itself.

[00:02:15]So, instead of this relationship where you pull, the elevator moves, the airplane responds, you had this. You pull, airflow helps the elevator move even more, the airplane pitches up more than commanded.

[00:02:27]And that's where it gets interesting, because once that starts, the elevator can continue to increase deflection without proportional pilot input. Now, let me translate that into pilot feel, because this is where it gets real.

[00:02:42]You're easing into the stall. Normally, you feel increased back pressure, predictable pitch response, a clear sense of air of where the airplane is going. But in this case, you pull, and the airplane says, "I'll take it from here."

[00:02:56]The nose keeps coming up, the angle of attack keeps increasing, and suddenly you're closer to the stall than you intended to be. It's really divergent here.

[00:03:06]Now, this isn't because you forced it, but because the airplane helped you get there.

[00:03:12]Now, from a certification standpoint, this is a big deal, because one of the fundamental requirements is the airplane must be predictable and controllable throughout the envelope, especially near the stall.

[00:03:25]You cannot have control forces that don't behave normally, surfaces that run away aerodynamically, or an airplane that amplifies pilot input in a critical regime.

[00:03:36]That's how accidents happened.

[00:03:38]And this is where Davies and pilots like him earn their pay, because this wasn't obvious on paper. It didn't show up cruising around at altitude. It showed up when you went right up to the edge of the envelope and asked, "What happens if I keep going?"

[00:03:54]And the airplane answered, "I'll help you stall."

[00:03:58]That's not the answer you want.

[00:04:00]So, what do you do? Well, you go back to the engineers and you say, "Hey, we got too much aerodynamic assistance on that elevator." So, they modify it. They reduce the balance effect, adjust hinge moments, change how the control feels.

[00:04:14]The goal is simple.

[00:04:16]When the pilot stops pulling, the airplane stops pitching up. That sounds basic, but getting that right is everything.

[00:04:25]Now, here's the takeaway I want you to think about. We tend to believe that airplanes only do what we tell them to do, but that's not entirely true.

[00:04:33]Airplanes are constantly trying to obey the laws of aerodynamics, and sometimes those laws don't line up perfectly with what the pilot expect. And when they don't, the airplane can get ahead of you and get away from you. So, here's the lesson. 50 years of flying, test flying, airline flying.

[00:04:52]The airplane doesn't just respond to you. It has a personality of its own.

[00:04:58]And in the case of the Ambassador, that personality said, "If you start to stall, I'll finish it."

[00:05:05]And that's exactly why certification testing matters, because you don't want an airplane that just flies. You want an airplane that behaves.

[00:05:16]Thanks for watching. Aviation Adventures with Captain Ron.