PILOT SPIN
Pilot Zone => Accident Review/Never Again (I hope..) => Topic started by: Rush on February 26, 2022, 08:14:17 AM
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I’d never heard of this incident. Very interesting, but at about minute 18 in this video he says three things improve the situation:
1. Air temp drops by 5 deg C giving the engines more thrust
2. Wind direction change gives more headwind “also giving them more speed”
3. They get the water glycol system back up increasing engine thrust
“These three things together start to cause the airplane to accelerate.”
Am I a total idiot here? Or is he saying something wrong? Number 1 and 3 make sense, but number 2 does nothing for airspeed. It in fact reduces relative ground speed, which is a good thing if you want to crash, try to land, but doesn’t actually do anything for your flyability. It doesn’t cause the plane to accelerate, except in the moment of the actual change in the wind velocity vector oncoming to the wing. That’s a relative acceleration between the air and the plane, momentarily, right? But once oriented into the headwind, air is no longer “accelerating” therefore not really helping, and they are actually left with only 1 and 3 helping them.
Or did momentary wind acceleration due to direction change bump up their velocity and it settled a couple knots higher? Is that what he means by “it gives them more speed?” If so I’m surprised it would have a significant effect. Would it even do that, or would it drop back down?
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These idiots produce the youtube videos looking for hits.
These are amateurs trying to convince you they are experts. Much like PoA, they typically are clueless.
I didn't click on the video to watch as I really don't want to give them a click nor waste my time looking at his "analysis".
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These idiots produce the youtube videos looking for hits.
These are amateurs trying to convince you they are experts. Much like PoA, they typically are clueless.
I didn't click on the video to watch as I really don't want to give them a click nor waste my time looking at his "analysis".
Also the picture is clickbait. The plane never hit anything and eventually landed safely back at the airport.
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Also the picture is clickbait. The plane never hit anything and eventually landed safely back at the airport.
Yep.
It's like those clowns on PoA that produce stupid videos then go there and start a thread in order to get more clicks.
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A headwind can increase your airspeed but NOT your ground speed.
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These idiots produce the youtube videos looking for hits.
These are amateurs trying to convince you they are experts. Much like PoA, they typically are clueless.
I didn't click on the video to watch as I really don't want to give them a click nor waste my time looking at his "analysis".
I take it then you agree that “gaining a headwind increases your speed” is a nonsense statement? I don’t recall ever being taught that having a headwind gives you an airspeed advantage but I’m not trained in extreme maneuvers. For all I know aerobatic fliers use turning into a headwind for a small acceleration boost and it’s a thing but if so I’ve never heard of it. I’d have to refresh myself in aerodynamics.
Let’s say you’re flying along with the wind direction coming from the 10:30 o’clock position relative to the ground. Your headwind component would be a fraction of the total wind speed relative to the ground (half? I haven’t flown in a while I forget) Then you turn left until you are directly into the wind, it’s now at your 12:00. So it has increased to the full amount.
No, that’s still totally relative to the ground, so you don’t experience any “acceleration” at all. You would if the plane instantaneously flipped direction but that’s not how it turns. It turns through the actual air.
So yeah the guy is an idiot. I think.
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A headwind can increase your airspeed but NOT your ground speed.
No, a tailwind increases your ground speed but not your airspeed.
A headwind decreases your ground speed but does nothing to your airspeed. Pitch and power changes influence your airspeed.
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No, a tailwind increases your ground speed but not your airspeed.
A headwind decreases your ground speed but does nothing to your airspeed. Pitch and power changes influence your airspeed.
Yes. Once you are flying you are one with the air and cannot even tell if you are IN a headwind except by checking your groundspeed.
Tim
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Yes. Once you are flying you are one with the air and cannot even tell if you are IN a headwind except by checking your groundspeed.
Tim
But, sudden changes in direction or speed of the wind can temporarily affect your airspeed, as in wind shear. In the picture below you can see how crossing this front would result in your airspeed suddenly decreasing, which is a problem if you are on approach for example, low and slow. This is what I am thinking. But it wouldn't result in a permanent airspeed change, given the same power and pitch. I think the guy in the video is implying the headwind gave them a speed boost, but if it did it could only be temporary. Am I right?
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But, sudden changes in direction or speed of the wind can temporarily affect your airspeed, as in wind shear. In the picture below you can see how crossing this front would result in your airspeed suddenly decreasing, which is a problem if you are on approach for example, low and slow. This is what I am thinking. But it wouldn't result in a permanent airspeed change, given the same power and pitch. I think the guy in the video is implying the headwind gave them a speed boost, but if it did it could only be temporary. Am I right?
This is what happens when amateurs try to explain things they are not knowledgeable of, and is the reason videos such as that are a waste of time.
PoA is loaded with self proclaimed "experts" that play this crap continuously.
But, sudden changes in direction or speed of the wind can temporarily affect your airspeed lift, as in wind shear.
FTFY
In true windshear the ASI becomes useless, it's pitch and power that matter.
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No, a tailwind increases your ground speed but not your airspeed.
A headwind decreases your ground speed but does nothing to your airspeed. Pitch and power changes influence your airspeed.
That's what I said. Tailwind increases ground speed. Headwind reduces ground speed. Airspeed should remain constant depending on pitch and power.
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That's what I said. Tailwind increases ground speed. Headwind reduces ground speed. Airspeed should remain constant depending on pitch and power.
No, you didn't say tailwind increases ground speed, you said headwind does NOT increase ground speed. That's not exactly the same thing. ;D
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This is what happens when amateurs try to explain things they are not knowledgeable of, and is the reason videos such as that are a waste of time.
PoA is loaded with self proclaimed "experts" that play this crap continuously.
FTFY
In true windshear the ASI becomes useless, it's pitch and power that matter.
But lift and airspeed are mathematically related so it actually affects both, but you are right, the ASI would be useless as my understanding is it needs a stable flow of air. And it is pitch and power, hence angle of attack that end up being the only real things creating lift or airspeed. But I am by no means an expert.
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In true windshear the ASI becomes useless, it's pitch and power that matter.
I partially disagree with that statement, although I think that the group generally fully understands the issue and agrees that the video (whatever it says--I didn't watch it either) is in error.
Anyway, pitch and power certainly are primary concerns, but one cannot ignore the airspeed indicator. Reason being, the ASI is showing the wind that the plane is flying in at the moment. That wind might change again at any moment, but whatever it says must be believed and accounted for, especially if the airspeed drops when close to the ground. In other words, apply pitch and power as required to maintain enough lift to stay flying.
Edit: I do agree that the ASI might be momentarily in error if the wind vector changes too fast for it. I still would not ignore it, though, because even though it may not be stabilized, it is showing the trend.
Tim
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hey, our very own treadmill thread...
:)
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I partially disagree with that statement, although I think that the group generally fully understands the issue and agrees that the video (whatever it says--I didn't watch it either) is in error.
Anyway, pitch and power certainly are primary concerns, but one cannot ignore the airspeed indicator. Reason being, the ASI is showing the wind that the plane is flying in at the moment. That wind might change again at any moment, but whatever it says must be believed and accounted for, especially if the airspeed drops when close to the ground. In other words, apply pitch and power as required to maintain enough lift to stay flying.
Edit: I do agree that the ASI might be momentarily in error if the wind vector changes too fast for it. I still would not ignore it, though, because even though it may not be stabilized, it is showing the trend.
Tim
In a windshear situation it's pitch/power. In a significant shear it becomes useless. Close to the ground and trying to interpret a trend on an ASI will end up putting the plane in the dirt.
Delta 191 tried flying airspeed and lost. Pan Am 759 focused on airspeed and never added pitch and power and lost as well.
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In a windshear situation it's pitch/power. In a significant shear it becomes useless. Close to the ground and trying to interpret a trend on an ASI will end up putting the plane in the dirt.
You're drawing a general conclusion from a worst-case scenario. It is true that in some circumstances a pilot may not have time to consult the ASI, but that doesn't make the gauge useless--it is still providing correct (if phase-shifted) information. In any event, we certainly agree much more than disagree, so I am not interested in getting into a pissing contest with you over something like this.
Tim
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You're drawing a general conclusion from a worst-case scenario.
No, I'm using training and facts.
In any event, we certainly agree much more than disagree, so I am not interested in getting into a pissing contest with you over something like this.
Tim
Whatever.
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You're drawing a general conclusion from a worst-case scenario. It is true that in some circumstances a pilot may not have time to consult the ASI, but that doesn't make the gauge useless--it is still providing correct (if phase-shifted) information. In any event, we certainly agree much more than disagree, so I am not interested in getting into a pissing contest with you over something like this.
Tim
In his defense we were talking about worst case scenario; severe wind shear. In your defense it's not like the ASI suddenly is completely non-functional. My first instinct would be pitch and power and not even look at the instrument. But like I said, I'm no expert whatsoever. We do all mostly agree in this thread.
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Just looking at AC 00-54, "Pilot Windshear Guide" (https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC00-54.pdf (https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC00-54.pdf) and seems to say the problem isn't the ASI per se that is the problem but rather the lack of prompt wind shear recognition and training that emphasized airspeed control in response to speed changes (e.g. pitch down if speed decreases.) When encountering decreased air speed indication due to wind shear requires accepting lower than normal air speed and higher than normally accepted pitch, even if, for example, it means risking a tail strike on takeoff when not enough remaining runway to abort takeoff. Anyway, that's my own short take from reviewing section "2.3 LESSONS LEARNED FROMWINDSHEAR ENCOUNTER" starting on page 14.
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This is what happens when amateurs try to explain things they are not knowledgeable of, and is the reason videos such as that are a waste of time.
PoA is loaded with self proclaimed "experts" that play this crap continuously.
FTFY
In true windshear the ASI becomes useless, it's pitch and power that matter.
If I recall, a lot was learned and sensors were developed after a DC-10 or L-1011 crashed at DFW in the 1980s. (I’m not in a position to look it up.)
EDIT: lucifer pointed out above that it was Delta 191. Thanks.