Watching the videos of the heavies crabbing to a landing in high cross winds
prompts me to ask: why don't they use asymmetrical thrust instead of
kicking it straight in the flare?

Even in a single, why don't we see more forward slips to a landing instead
of crab, kick, and pray?

Have these techniques gone the way of the steam gauges?

Jim Carter wrote:
> Watching the videos of the heavies crabbing to a landing in high cross winds
> prompts me to ask: why don't they use asymmetrical thrust instead of
> kicking it straight in the flare?

Too slow and too hard to manage.


> Even in a single, why don't we see more forward slips to a landing instead
> of crab, kick, and pray?

Poor instructors.


> Have these techniques gone the way of the steam gauges?

The first technique (differential thrust) never existed to my knowledge
and the second technique is alive and well with well-trained pilots.

Matt

Matt Whiting wrote:
>> Watching the videos of the heavies crabbing to a landing in high cross winds
>> prompts me to ask: why don't they use asymmetrical thrust instead of
>> kicking it straight in the flare?
>
> Too slow and too hard to manage.


At least in a jet. The time delay involved in spooling up probably has the most
to do with it not being currently used.


>> Even in a single, why don't we see more forward slips to a landing instead
>> of crab, kick, and pray?
>
> Poor instructors.
>
>
>> Have these techniques gone the way of the steam gauges?
>
> The first technique (differential thrust) never existed to my knowledge
> and the second technique is alive and well with well-trained pilots.


I've used differential thrust before so I know the technique exists. However I
was flying something with piston engines which essentially had instant reaction
to throttle inputs. Passengers liked it better than the more usual methods
because it presented them with a more conventional view looking out the window,
hence less anxiety. When you land on just one wheel after a successful slip to
a landing, they think you've screwed up.



--
Mortimer Schnerd, RN
mschnerdatcarolina.rr.com

On 2008-03-11, Matt Whiting > wrote:
>> Even in a single, why don't we see more forward slips to a landing instead
>> of crab, kick, and pray?
> Poor instructors.

Interesting...because the first CFI I flew with in 15 years had me use the
exact same technique my primary instructor taught me: point it down the
runway with the rudder, hold it over the centerline with the ailerons. I had
thought that was the standard light aircraft approach to the problem.

>> Have these techniques gone the way of the steam gauges?
> The first technique (differential thrust) never existed to my knowledge

I wouldn't expect differential thrust to be manageable with a
turbofan/turbojet because of the time lag between throttle and thrust.
--
Jay Maynard, K5ZC http://www.conmicro.com
http://jmaynard.livejournal.com http://www.tronguy.net
http://www.hercules-390.org (Yes, that's me!)
Buy Hercules stuff at http://www.cafepress.com/hercules-390

John R. Copeland wrote:

> "Jim Carter" > wrote in message
> . net...
>> Watching the videos of the heavies crabbing to a landing in high cross
>> winds prompts me to ask: why don't they use asymmetrical thrust instead
>> of kicking it straight in the flare?
>>
>> Even in a single, why don't we see more forward slips to a landing
>> instead of crab, kick, and pray?
>>
>> Have these techniques gone the way of the steam gauges?
>>
>
> You want to rethink that a little, Jim?
> How would asymmetrical thrust align the aircraft with the runway?
>
> Also, forward slips are used to lose altitude. Sideslips compensate
> crosswinds.
>
> But to answer that question anyway, neither steam gauges nor sideslips are
> gone. I use both of them in my light twin, except that I try to keep my
> transition from crab to slip reasonably smooth, and combined with my
> pre-landing flare.


When I went thru multi training we used asymmetrical thrust a lot in
Oklahoma (cause the wind never stops) to control approach attitudes. I
hadn't thought the lag time was still that significant on the modern
turbofans, so I made a bad assumption that the technique would be
applicable to the heavies.

It's been so long now I'm not sure I remember the technique right off hand,
but I believe we carried more power on the upwind engine and banked into
the wind. We didn't have to ride the rudders like in a single engine and it
was much easier, prettier, and somewhat more stable in a crosswind.

You're right - I got my slips reversed. Side slip into the wind, forward
slip toward the runway. It's all relative to the line of travel.

I wonder what the response time is for the large modern turbofans.

On Mar 10, 4:34*pm, Jim Carter > wrote:
> Watching the videos of the heavies crabbing to a landing in high cross winds
> prompts me to ask: why don't they use asymmetrical thrust instead of
> kicking it straight in the flare?
>
> Even in a single, why don't we see more forward slips to a landing instead
> of crab, kick, and pray?
>
> Have these techniques gone the way of the steam gauges?

Slipping has been used for crosswind technique long before crab&kick.
The crab&kick was only made possible by the invention of the
nosewheel.

-Robert

..
"Jim Carter" > wrote in message
...
<...>
>
> You're right - I got my slips reversed. Side slip into the wind, forward
> slip toward the runway. It's all relative to the line of travel.
>


The way to remember it is that the names are backwards - in a side slip you
look forward, and in a forward slip you look out to the side to see where
you are going.


--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate

"Jim Carter" > wrote in message
. net...
> Watching the videos of the heavies crabbing to a landing in high cross
> winds
> prompts me to ask: why don't they use asymmetrical thrust instead of
> kicking it straight in the flare?
>
> Even in a single, why don't we see more forward slips to a landing instead
> of crab, kick, and pray?

I see no reason to pray. There's little difference in out come with the
crab technique or the forward slip. One you put the plane in a slip early
and keep constant control pressures thru-out your approach and the other you
put the plane in a crab, relax your control inputs and put the plane in a
slip in the last 10 seconds or so. Either the plane has enough rudder
authority or it doesn't in either situation. Neither is superior IMO and
definitely neither makes one a super pilot over the other. Seems to be
personal preference.

If you are proficient at one of these techniques you've got it covered. I
don't think that there is any situation when one of these crosswind landing
techniques is the preferred and only safe way to land over the other.

Kobra

Kobra wrote:
>> Even in a single, why don't we see more forward slips to a landing instead
>> of crab, kick, and pray?
>
> I see no reason to pray. There's little difference in out come with the
> crab technique or the forward slip.



There is one reason you should always pray: the wind is seldom a constant. As
you're coming in on short final and the wind rapidly shifts, will it happen at
the worst possible time? Will it do something so violent as to be totally
unexpected and leaving you no time to recover? *That's* why you should pray.

I can recall what started as a normal but gusty landing in a Cherokee Six. I
touched down acceptably and rolled a couple of hundred feet, then found myself
flying again; only this time I was cocked into the wind at about a 40 degree
angle to the runway at an altitude of about 2 feet. I had been rolling so far
after my touchdown that I had completely relaxed; all that was left to do was
taxi. Heh heh... the wind had other ideas. I firewalled it and managed to keep
from coming down sideways. *That's* the kind of stuff that causes me to pray at
hinky moments.



--
Mortimer Schnerd, RN
mschnerdatcarolina.rr.com

A B-52 pilot told me part of the approach setup was to dial in the right
angle for the landing gear so a crab would be possible while the plane was
rolling straight down the runway.

"Kobra" > wrote in message
. ..
>
> "Jim Carter" > wrote in message
> . net...
> > Watching the videos of the heavies crabbing to a landing in high cross
> > winds
> > prompts me to ask: why don't they use asymmetrical thrust instead of
> > kicking it straight in the flare?
> >
> > Even in a single, why don't we see more forward slips to a landing
instead
> > of crab, kick, and pray?
>
> I see no reason to pray. There's little difference in out come with the
> crab technique or the forward slip. One you put the plane in a slip early
> and keep constant control pressures thru-out your approach and the other
you
> put the plane in a crab, relax your control inputs and put the plane in a
> slip in the last 10 seconds or so. Either the plane has enough rudder
> authority or it doesn't in either situation. Neither is superior IMO and
> definitely neither makes one a super pilot over the other. Seems to be
> personal preference.
>
> If you are proficient at one of these techniques you've got it covered. I
> don't think that there is any situation when one of these crosswind
landing
> techniques is the preferred and only safe way to land over the other.
>
> Kobra
>
>

Jim Carter wrote:
> Watching the videos of the heavies crabbing to a landing in high cross winds
> prompts me to ask: why don't they use asymmetrical thrust instead of
> kicking it straight in the flare?
>
> Even in a single, why don't we see more forward slips to a landing instead
> of crab, kick, and pray?
>
> Have these techniques gone the way of the steam gauges?
>

Using differential thrust would be asking for disaster.

The proper technique is fly the crab just as you would do an an ILS
localizer to remain on course during a crosswind. It is not a crab;
rather, a coordinated flight wind correction (track vs heading.

Then, as the flare begins down aileron is placed into the wind as the
opposite rudder is used to align the nose with the runway. If down
correctly, the wings remain level as the aircraft touches down, thus
preventing an engine pod from scraping the runway.

It wasn't always taught this way, but has since at least 1980, or so.
It had to be demonstrated on rating rides in the simulator with maximum
certified crosswind for the airplane.

In article >,
Capt. Geoffrey Thorpe <The Sea Hawk At Wow Way D0t C0m> wrote:
>.
>"Jim Carter" > wrote in message
...
><...>
>>
>> You're right - I got my slips reversed. Side slip into the wind, forward
>> slip toward the runway. It's all relative to the line of travel.
>>
>
>
>The way to remember it is that the names are backwards - in a side slip you
>look forward, and in a forward slip you look out to the side to see where
>you are going.

It's all semantics. A slip is a slip is a slip. The airplane doesn't know
the difference between a side slip and a forward slip because they are
aerodynamically identical. The only difference between a forward slip and a
side slip is the reason that the pilot is doing the slip: one is for
losing altitude without gaining airspeed, and the other is for staying
lined up on a runway in a crosswind.

-- Dane