When an airplane stalls, does it feel like those rides at the amusement park where you get strapped into a seat, the seat goes up a 100-foot tower, and then your seat (and you) suddenly plummets at free fall?
No, it’s quite gentle. The sensation of falling is very brief and not very extreme.
Oh - is it because the body quickly becomes accustomed to the rate of fall and therefore after a few seconds it doesn’t sense freefall anymore?
Also, for clarification, despite my thread title, I’m not implying that there is anything enjoyable or entertaining about an airplane stall, which can have deadly effect; just in case anyone misunderstands.
And I am referring to the direst-possible stall, if that makes sense…like the kind on Air France 447 that ultimately killed everyone aboard; I’m assuming they were plummeting at an extremely fast speed.
I don’t know. I rode in a American (Airlines) Eagle from Dallas to Houston. I’m not sure what kind of plane it was but it flew on two prop engines.
As far as I know, we didn’t have any engine stalls but it still felt like an amusement park ride.
I enjoyed it though because I’m weird like that.
Pretty much. Also the fall is very brief. On most aircraft that you are able to practice stalling in it is very difficult to get it remain stalled. Normally it’s a gentle pitch down then a few seconds later you’re flying again. If you hold the stick back to try and maintain the stall you will typically end up spinning which involves positive g and therefore no real sensation of falling.
Actually, given the proper situation, stall recovery practice can get to be a bit fun, which I say as a pilot who doesn’t particularly like stalls in general. Recovery practice, though, is done intentionally and in a manner that is safe as opposed to a stall you’re not expecting and might be in a hazardous situation.
A stall can be abrupt, but it’s unlikely on a modern airplane.
As Richard Pearse noted, stalls are usually quite brief. Typically you either recover very quickly (the overwhelming majority of instances) or you spin (pretty rare these days) which is a very different sensation and no, you don’t feel like you’re falling or in freefall. Even with stalls you don’t normally have an episode of freefall because, while you’re descending, it’s usually not fast enough to generate that feeling.
In the Air France case they probably didn’t feel the stall, what they felt on the way down were the wild and extreme banks that occurred during the descent. While I’m not a airplane accident investigator, when I read the official report on the accident I got the sense it was almost fluttering down like a falling leaf except, of course, it wasn’t a leaf it was a big airplane full of people.
In aviation a “stall” does not mean the engine shut off. Instead, it is the loss of aerodynamic lift on the airframe resulting from (typically) insufficient speed combined with an aggressive “angle of attack” (the angle at which the airfoil is intersecting the oncoming airflow).
Almost half of all “real” stalls, that is unintentional stalls that occur outside of stall recovery practice, occur below 250’. So in general when you practice the stall recovery you’re trying to lose as little altitude as possible. As others have said, typically what it feels like is simply a slight pitch forward as the nose of the plane drops until it recovers lift.
Not really - they were descending at a roughly constant speed of around 108 kts. But this certainly was the “direst” type of stall: a “deep” stall that persisted for over 3 minutes.
A sensation of falling lasts only as long as you are accelerating downward, which in an aerodynamic stall rarely lasts more than a few seconds. For a long sensation of falling, you need to fly like the “Vomit Comet” does: in a parabolic arc that can give 20+ seconds of zero-G.
Nitpick:
In common usage, yes, stall refers to separation of airflow over the top surface of the aircraft’s wings and the associated loss of lift. But for turbomachinery (this includes the engines on jet-powered aircraft), it can also refer to compressor stall, in which the compressor blades experience a similar loss of aerodynamic “lift”, resulting in a loss of engine compression. It can happen more easily under certain operating conditions, and it can also be caused from damage to the compressor blades, e.g. from a birdstrike. This ThomsonFly 757 exhibits repeated compressor stall events after the starboard engine ingests a bird right at the moment of liftoff. Each time the compressor stalls, the engine barks flame out the back and loses combustion chamber pressure; so relieved of pressure, the compressor blades are able to restore normal airflow and begin building combustion chamber pressure again, up to the point that the damaged/misshapen compressor blades can no longer sustain it - and then the stall happens again. The cycle repeats a couple of times per second until the pilot finally kills the engine (and the passengers stop shitting their pants).
My recollections of intentional stalling during my early days of flight training don’t involve any sensation of free fall, probably because there is very little or no actual free fall at all. The only time you’re going to truly get any extended free fall in an airplane is if it hits a major air pocket or, as in the Vomit Comet, is on a ballistic trajectory.
The major sense you get when approaching a stall is that the airplane really, really does NOT want to be doing this, and when you actually stall it starts shaking and shuddering in a pretty unmistakable sign of distress. Plus, of course, at this point it’s no longer flying so it’s unstable as hell and easily set into a spin. Recovering from a spin-stall is probably the most harrowing part of flight training for a novice, although instructors seem pretty cool about it!
When I take people for rides in a glider I often ask them if they like the “roller coaster” feeling. If they “yes” and want to try a stall I tell them what I am going to do and then do it. I put the nose down a bit to pick up a little speed and then pull back fairly quickly on the stick. Up goes the nose, the speed bleeds off rapidly, the wings stall and down goes the nose. There is a definite stomach drop - zero or slight negative G as we nose over. The wing un-stalls and we are flying again. Unintended stalls are much more subtle and you may get little, if any, stomach drop.
Intended stalls are normally more subtle as well. What you are doing is an accelerated stall where you are using a bit of ‘g’ loading to help initiate the stall. In a typical basic stall training exercise you would just fly straight and level (engine at idle for a powered machine) and wait for the speed to wash off. It takes a lot longer to happen and because the pitch attitude prior to the stall is just enough to stay level the nose drop is far less pronounced.
My coworkers and I went to a computer conference in LA around 1992 or 93. Half of them returned on an early flight. A few of us were on a later flight.
The early flight had a sudden drop (air pocket?) all the oxygen masks dropped, stuff in the cabin went flying. A few screams and OMG’s. One lady I worked with had a sore neck for a couple weeks and saw a doctor. It was pretty scary from the way they described it. I doubt it lasted more than 20 seconds but it sure shook them up.
I’m glad that I was on that later flight.
It should perhaps be noted that there’s no such thing as an “air pocket”. Or perhaps more accurately that this is an awkward and misleading term for turbulence or vertical gusts that produce brief negative Gs in aircraft that encounter them.
True it’s a terrible misnomer.
But most turbulence does NOT produce negative Gs. It merely produces positive G forces less than the 1.0 we’re all used to.
Right - turbulence severe enough to do that is (fortunately) somewhat unusual.
My BIL tells a story of a 747 flight from Washington to LA: Shortly after a meal had been served, they hit turbulence severe enough to injure a few people - and spread lasagna, salad, drinks, etc. all around the cabin. Some of it was still dripping from the ceiling as they were landing.
That standard advice to keep your belt fastened when seated is sound.
And keep your lasagne buckled up too.
Rare, but it does happen. there have been cases of people on commercial flights who sustained severe (even fatal) head injuries during clear-air turbulence; they weren’t wearing their seat belt, and ended up slamming their head on the ceiling.
Here’s the aftermath of an incident that randomly redistributed everyone’s dinner.
Turns out there is a smartphone app for measuring turbulence (basically a g-meter). Would be helpful for some folks to understand that even when it feels awfully bouncy, the actual g level is, in most cases, nowhere near the aircraft’s limits.