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Search: Posts Made By: Vessbot
Showing results 1 to 35 of 42
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Forum: Tech Log
7th Aug 2018, 02:38
Replies: 330
Views: 50,667
Posted By Vessbot

To make sure you haven't lost the plot -- what do...

To make sure you haven't lost the plot -- what do you think my (attempted) point is?
Forum: Tech Log
7th Aug 2018, 02:32
Replies: 330
Views: 50,667
Posted By Vessbot

Do you think there's an error in the math? If so,...

Do you think there's an error in the math? If so, what is it? First you weren't happy that there were negative groundspeeds, so now that they're all positive, then what?
Do you apply that same...
Forum: Tech Log
7th Aug 2018, 02:25
Replies: 330
Views: 50,667
Posted By Vessbot

Get real. You know the two are collquially...

Get real. You know the two are collquially interchangable, and you know exactly what I meant. The point isn't just flying by you, you're actively dodging it. Look one post up.
Forum: Tech Log
7th Aug 2018, 02:14
Replies: 330
Views: 50,667
Posted By Vessbot

OK, Scenario B2 (really fast running person...

OK,

Scenario B2 (really fast running person inside airliner. He runs at 501 knots and can turn around on a dime.)
final groundspeed minus initial groundspeed
(airspeed + tailwind) - (airspeed -...
Forum: Tech Log
7th Aug 2018, 02:09
Replies: 330
Views: 50,667
Posted By Vessbot

OK, and? text filler

OK, and?

text filler
Forum: Tech Log
7th Aug 2018, 02:05
Replies: 330
Views: 50,667
Posted By Vessbot

Yes!! When defined as positive one way, negative...

Yes!! When defined as positive one way, negative the other. You know, like that nonsensical useless system called longitude.
Forum: Tech Log
6th Aug 2018, 22:32
Replies: 330
Views: 50,667
Posted By Vessbot

Aka the speed is negative 10

Aka the speed is negative 10
Forum: Tech Log
6th Aug 2018, 21:20
Replies: 330
Views: 50,667
Posted By Vessbot

It's not a whim, it's perfectly in accordance...

It's not a whim, it's perfectly in accordance with the simple principle that groundspeed is airspeed minus headwind component.
Forum: Tech Log
6th Aug 2018, 20:45
Replies: 330
Views: 50,667
Posted By Vessbot

Apparently groundspeed = | airspeed - headwind | ...

Apparently groundspeed = | airspeed - headwind |

Ever since the 3rd grade I always wondered when in the world you'd ever use the | | symbol to strip out a negative, and I've finally found it!
Forum: Tech Log
6th Aug 2018, 20:02
Replies: 330
Views: 50,667
Posted By Vessbot

Jet Fan, I think it's time me and you resign from...

Jet Fan, I think it's time me and you resign from this part of the project, and think up a new and different counterexample to demonstrate that initial and final ground velocity is irrelevant to...
Forum: Tech Log
6th Aug 2018, 19:47
Replies: 330
Views: 50,667
Posted By Vessbot

Or you can say that the airspeed is negative. I...

Or you can say that the airspeed is negative. I think communication is goddamn impossible sometimes. One time my boss was trying to tell me there's no such thing as negative lift. Definitions and...
Forum: Tech Log
6th Aug 2018, 19:46
Replies: 330
Views: 50,667
Posted By Vessbot

No it's not, if you simply define groundspeed as...

No it's not, if you simply define groundspeed as the component of velocity of the ground relative to the airplane's X axis, signed as positive moving nose-to-tail.

And don't act as if this is...
Forum: Tech Log
6th Aug 2018, 19:41
Replies: 330
Views: 50,667
Posted By Vessbot

This is true. But why does it matter? ...

This is true. But why does it matter?



This is true too.



Also true...
Forum: Tech Log
6th Aug 2018, 18:10
Replies: 330
Views: 50,667
Posted By Vessbot

It's zero in relation to the body axes, but that...

It's zero in relation to the body axes, but that definition starts being useless then. You can say it's 500 sideways, which is kinda clunky and not useful for much, but it is at least useful in...
Forum: Tech Log
6th Aug 2018, 18:07
Replies: 330
Views: 50,667
Posted By Vessbot

It's embarrassing that the people on the correct...

It's embarrassing that the people on the correct side are chasing their tails on definitions and reference frames. Brercrow must be (justifiably) having a good laugh.

Yes, if you consider the...
Forum: Tech Log
6th Aug 2018, 17:41
Replies: 330
Views: 50,667
Posted By Vessbot

It looks like you're moving backwards. It's what...

It looks like you're moving backwards. It's what happens when you fly at 50 knots airspeed into a 60 knot headwind. Groundspeed is -10 knots.



Fortunately for the guy with the negative...
Forum: Tech Log
6th Aug 2018, 15:57
Replies: 330
Views: 50,667
Posted By Vessbot

Quit being a martyr. You know it's perfectly...

Quit being a martyr. You know it's perfectly reasonable, given the standard set of assumptions, to say that your groundspeed is 90 knots one way, then 110 the other way. In fact, before this thread,...
Forum: Tech Log
6th Aug 2018, 15:55
Replies: 330
Views: 50,667
Posted By Vessbot

Say there's no wind (it's one of those perfect...

Say there's no wind (it's one of those perfect mornings) and you're flying around. You fly East for a while at 100 knots airspeed, and turn around and fly West. By that same premise, your airspeed is...
Forum: Tech Log
6th Aug 2018, 15:45
Replies: 330
Views: 50,667
Posted By Vessbot

Hell we do the same thing about airspeed too, and...

Hell we do the same thing about airspeed too, and necessarily so. The positive sign is always applied when air is coming from the direction of the nose, and we take that axis with us wherever we...
Forum: Tech Log
6th Aug 2018, 15:41
Replies: 330
Views: 50,667
Posted By Vessbot

Sure you can. If your last sentence is true, then...

Sure you can. If your last sentence is true, then it is not a meaningful analysis that in Scenario A the Cessna went from 90 to 110 groundspeed when turning East to West. Did you look at scenario A?...
Forum: Tech Log
6th Aug 2018, 15:23
Replies: 330
Views: 50,667
Posted By Vessbot

Oh Christ. You're anchoring the +/- to the...

Oh Christ. You're anchoring the +/- to the geographical direction. I was leaving them anchored to the body. Yes I can belabor the point and rework everything to keep to a geographical frame, but the...
Forum: Tech Log
6th Aug 2018, 15:14
Replies: 330
Views: 50,667
Posted By Vessbot

The airliner (= airmass container = wind) is...

The airliner (= airmass container = wind) is flying WEST at 500 knots. The person is initially walking East (1 knot airspeed, -499 groundspeed) turning around to West (1 knot airspeed, 501 knots...
Forum: Tech Log
6th Aug 2018, 15:07
Replies: 330
Views: 50,667
Posted By Vessbot

Do you apply the same criticism to a Cessna...

Do you apply the same criticism to a Cessna flying on an East heading in an East-to-West wind?

I'll tell you the same thing I told Brercrow: Look at scenario A, and see that everything checks out,...
Forum: Tech Log
6th Aug 2018, 14:49
Replies: 330
Views: 50,667
Posted By Vessbot

He's moving backward. His (body) groundspeed...

He's moving backward. His (body) groundspeed could not be in the positive unless he's running toward the tail at greater than 500 knots.

What's a Cessna's groundspeed when flying at 50 knots...
Forum: Tech Log
6th Aug 2018, 14:33
Replies: 330
Views: 50,667
Posted By Vessbot

Yes, there will be, for the reason explained by...

Yes, there will be, for the reason explained by the math I posted.

What's the groundspeed before the turn? -499
What's the groundspeed after the turn? 501

The difference is 1000.

I read...
Forum: Tech Log
6th Aug 2018, 13:57
Replies: 330
Views: 50,667
Posted By Vessbot

Scenario A (Cessna) final groundspeed minus...

Scenario A (Cessna)
final groundspeed minus initial groundspeed
(airspeed + tailwind) - (airspeed - headwind)
(100+10)-(100-10)
110-90
20

Scenario B (Person inside airliner)
final...
Forum: Tech Log
5th Aug 2018, 18:49
Replies: 330
Views: 50,667
Posted By Vessbot

I don't have as pessimistic of an outlook of it...

I don't have as pessimistic of an outlook of it as you do. I think he is actually engaging in honest argumentation.
Forum: Tech Log
4th Aug 2018, 21:33
Replies: 330
Views: 50,667
Posted By Vessbot

Everything in black in those figures is correct....

Everything in black in those figures is correct. The overlaid blue triangles, though, are nonsense for the reason I explained earlier in post 174.

In still air, angle d would be zero and therefore...
Forum: Tech Log
4th Aug 2018, 14:45
Replies: 330
Views: 50,667
Posted By Vessbot

He has a whole website of it, which has been...

He has a whole website of it, which has been linked to multiple times in the thread:

The Downwind Turn (http://www.dynamic-soaring-for-birds.co.uk/html/the_downwind_turn.html)
Forum: Tech Log
4th Aug 2018, 14:43
Replies: 330
Views: 50,667
Posted By Vessbot

OK, let's talk about what's happening DURING the...

OK, let's talk about what's happening DURING the turn then. Do you notice anything unusual during the turn as you turn through the thousand knot self-created shear within a second? I don't. And my...
Forum: Tech Log
3rd Aug 2018, 03:25
Replies: 330
Views: 50,667
Posted By Vessbot

That is an error (as I pointed out in my own post...

That is an error (as I pointed out in my own post that you quoted) but not the error, as Excel can't do math on diagrams. But you're welcome to look through his math more specifically, maybe you'll...
Forum: Tech Log
2nd Aug 2018, 23:31
Replies: 330
Views: 50,667
Posted By Vessbot

I wish the tone in here didn't have to get nasty,...

I wish the tone in here didn't have to get nasty, though I understand (and experience myself) the frustration when the other side doesn't see things one's own way. Hopefully it can return to...
Forum: Tech Log
28th Jul 2018, 02:22
Replies: 330
Views: 50,667
Posted By Vessbot

Has the thread turned downwind and lost airspeed?

Has the thread turned downwind and lost airspeed?
Forum: Tech Log
26th Jul 2018, 02:25
Replies: 330
Views: 50,667
Posted By Vessbot

Well things went dead quickly... surely I...

Well things went dead quickly... surely I couldn't have had the last word, could I? :ooh:
Forum: Tech Log
24th Jul 2018, 01:33
Replies: 330
Views: 50,667
Posted By Vessbot

Here's a typical flight example of the windward...

Here's a typical flight example of the windward turn that should suffer an airspeed loss according to the windward turn theorists:

Vehicle making the turn: Cessna 172
Wind (uniform airmass over...
Showing results 1 to 35 of 42
 
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