Page 1 of 1

Wake Turbulence [i]there[/i].

Posted: Mon Jan 09, 2017 3:41 pm
by 3WE
I hereby proclaim that it is bologna for 747's to worry about wake separation distances from other 747's (within common sense and normal operations, of course)

For littler planes following bigger planes, yeah sure. But most of the rest of the time:

-172's don't worry about wake turbulence from 172's
-737's don't worry about wake turbulence from 737's
-and numerous other examples of different models with similar weight and performance

The behavior of aircraft wakes means that similar aircraft flying similar approach courses will generally never encounter each other's wake, except for light quartering tail winds: https://www.faa.gov/air_traffic/publica ... -03-14.pdf Fig 7-3-3, 4, 5, 6, 7.

Yes, this is a blatant double post, but I hope for genius airmanship discussion here, not procedure-lovers and photographers.

Re: Wake Turbulence [i]there[/i].

Posted: Tue Jan 10, 2017 2:13 am
by Gabriel
Here is proof that you are wrong :twisted:

https://www.youtube.com/watch?v=i50-FUjs_Dc

Re: Wake Turbulence [i]there[/i].

Posted: Tue Jan 10, 2017 2:44 am
by 3WE
I see no evidence that the trailing 747 encountered the wake of the proceeding one.

The first plane makes as many, if not more control deflections.

Plus, one other person has a somewhat similar opinion that the hard looking landing may not be due to the wake...AND this gives me great pride.

Re: Wake Turbulence [i]there[/i].

Posted: Tue Jan 10, 2017 4:03 am
by Gabriel
I see no wake of the proceeding one.
Of course not. The wake is invisible (most of the times anyway).

Re: Wake Turbulence [i]there[/i].

Posted: Tue Jan 10, 2017 12:41 pm
by 3WE
I see no wake of the proceeding one.
Of course not. The wake is invisible (most of the times anyway).
Nice try, and yes, I acknowledge humourous intent.

The aggie scientist used the word 'evidence'.

The aggie again challenges the hell better aeroengineer...the sort of sudden, fairly straight down planting of the final few feet of the landing could indeed theoretically be some help from a wake...

BUT

It could be a whole lot of other things, including "a garden-variety pranger".

The overall aircraft motion and control surface movements show no evidence of a significant roll (something you might expect from a wake). The vertical movement of the plane shows evidence of numerous potential causes that are not_wake related.

Now, shall we debate good ole stick shift tractor transmissions versus the more automated, modern hydroshift and whether that affects soil compaction?

Re: Wake Turbulence [i]there[/i].

Posted: Tue Jan 10, 2017 4:01 pm
by Not_Karl
It could be a whole lot of other things
Are you challenging the title of a Youtube video? :o

Re: Wake Turbulence [i]there[/i].

Posted: Tue Jan 10, 2017 6:59 pm
by Gabriel
Nice try, and yes, I acknowledge humourous intent.
Do you acknowledge it for my first post too? (although I would use the word irony)

Re: Wake Turbulence [i]there[/i].

Posted: Tue Jan 10, 2017 7:20 pm
by 3WE
It could be a whole lot of other things
Are you challenging the title of a Youtube video? :o
Indeed,

However;

it is a necessary side effect of stirring crap on obscure aviation discussion fora.

I like Gabe, the-hell-better-aeroengineer, but sometimes Calculus 5, Differential Equations, Physics 3, dynamics, statics, structures, electronics, and aeronautics, numerical methods, AND coming up with scientific, type-specific procedures AND working with cheap composites, AND enduring life-threatening, Av-Herald-worthy turbulence...

...he sometimes forgets the fundamentals that wake turbulence is generally a rotating thingie that causes uncommanded roll inputs moreso than they do an inadequate measured flare pull-up and firm landing...

...what we see in the YouTube is no_hints of roll, and more of a garden-variety pranger, according to some not-so-tall, but moustache-lacking pilot.

Fortunately Gabe (and you?) are expressing at least some interest in the topic here. There is very little apparent interest there.

I also greatly appreciate Flyboy's input in a third thread.

Re: Wake Turbulence [i]there[/i].

Posted: Tue Jan 10, 2017 7:47 pm
by 3WE
Nice try, and yes, I acknowledge humourous intent.
Do you acknowledge it for my first post too? (although I would use the word irony)
Acknowledged.

Re: Wake Turbulence [i]there[/i].

Posted: Wed Jan 11, 2017 5:25 am
by Gabriel
What I see is that the second Jumbo is approaching at a quite faster vertical speed before the flare.

Re: Wake Turbulence [i]there[/i].

Posted: Wed Jan 11, 2017 12:31 pm
by 3WE
What I see is that the second Jumbo is approaching at a quite faster vertical speed before the flare with no significant rolling.
Fixed.

I note that a pilot suggested that the second 747 was making a high approach and "dive" potentially to avoid wake turbulence, but that does not mean that wake turbulence caused the solid landing.
Have you checked to see if there are light quartering tailwinds?

Re: Wake Turbulence [i]there[/i].

Posted: Wed Jan 11, 2017 2:23 pm
by flyboy2548m
Let it go already.

Re: Wake Turbulence [i]there[/i].

Posted: Sun Jan 15, 2017 2:48 pm
by 3WE
Apologies for belaboring things.

I was hoping for someone to say (in simple terms)

Yes, 3BS, you make a valid point.

OR

No, actually the wake from a jumbo heavy jet could dangerously disrupt another jumbo heavy jet in the case of mild cheating (like shown in the video)- even though we give much less attention to lighter airliners following each other.

However, I accept that lack of discussion here and there is the norm. Thanks.

Re: Wake Turbulence [i]there[/i].

Posted: Mon Jan 16, 2017 7:07 am
by Sickbag
Yes

Re: Wake Turbulence [i]there[/i].

Posted: Thu Jan 19, 2017 5:13 am
by Not_Karl
Yes
wrong