3 more Qs

[Ramapriya]

1. Like there are crosswind landings, are there crosswind takeoffs too?
If yes, what's the procedure of takeoff?

2. In crosswind landings, it's recommended that one lands on only the
upwind wheel. Since this would almost always tilt the upwind wing
groundward, would there not be an engine strike? I'm especially
thinking of aircraft like the 737 and A320...

3. How to slip an aircraft sideward? I'm visualizing a situation on
final when a draft of air suddenly blows the aircraft a bit off-center
and when it might be a bit late to try and bank the craft to get it
back into proper alignment.

Thanks,

Ramapriya

[Gene Seibel]

1) Yes, on a crosswind takeoff you put aileron into the wind and use
rudder to stay aligned with the runway. One instructor had me do an
exercise in which I lifted up on one wheel in a crosswind takeoff and
proceeded a good distance down the runway in that condition.

2) Airliners bank into the wind too, but the degree of bank is much
less, since the crosswind is a smaller percentage of airspeed. I'm sure
engine strikes have happened, but it's not a common problem.

3) In gusty winds, it's often necessary to make sudden corrections of
both the rudder and aileron to stay centered on the runway. Many years
ago I had the wind change from a right to a left crosswind at the
instant of touchdown. Slammed me into the runway on the nosewheel and
right main. Thought for sure I had broken the airplane.
--
Gene Seibel
Confessions of a Pilot - http://pad39a.com/publishing/
Because I fly, I envy no one.

[Bob Moore]

"Gene Seibel" wrote

> 2) Airliners bank into the wind too, but the degree of bank is much
> less, since the crosswind is a smaller percentage of airspeed. I'm sure
> engine strikes have happened, but it's not a common problem.

Not really Gene...airliners with wing mounted engines almost
always crab into the crosswind rather than banking. Engine
strikes are a serious problem. In the B-707 that I flew for
17 years, we crabbed and then using the rudder, "kicked-out"
the crab at the last second before touchdown. Boeing said
that if one was not comfortable doing that, just touchdown in
the crab. Of course autoland approaches always use the crab
into the wind method with the autopilot taking out the crab
just before touchdown.

Bob Moore
CFI ATP B-707 B-727

[Ramapriya]

Y'know what Bob, almost the only aircraft I saw in Khartoum that
belonged to the national and private airliners were either 727s
(predominantly) or 707s :)

I could be wrong but I got the impression that the 707s made more noise
than comparable-sized aircraft...

Cheers,

Ramapriya

[Gene Seibel]

Thanks for the correction. Shouldn't have speculated beyond on my
experience. ;)
--
Gene Seibel
Gene & Sue's Aeroplanes - http://pad39a.com/gene/planes.html
Because I fly, I envy no one.

[Ramapriya]

Bob Moore wrote:
>
> the crab at the last second before touchdown. Boeing said
> that if one was not comfortable doing that, just touchdown in
> the crab. Of course autoland approaches always use the crab

Sorry for being naive here Bob, but does touching down with the nose
not pointed down the center of the airstrip, which is what I presume
would happen if you touched down in the crab, bust the wheels? I'm
thinking of the stress my ankles would be under if I had to jump down
from somewhere at an angle to my eventual follow-through (unsure
whether or not that's a silly comparison).

Ramapriya

[Bob Moore]

"Ramapriya" wrote
> Sorry for being naive here Bob, but does touching down with the nose
> not pointed down the center of the airstrip, which is what I presume
> would happen if you touched down in the crab, bust the wheels?

Certainly not good for light general aviation aircraft, but the
Boeings seem to take it easily.

Bob

[G.R. Patterson III]

Ramapriya wrote:
>
> 1. Like there are crosswind landings, are there crosswind takeoffs too?
> If yes, what's the procedure of takeoff?

Yes. The aileron on the upwind wing is raised as if you were banking the
aircraft in that direction. The aircraft is kept straight by use of rudder. The
nosewheel or tailwheel is usually kept down a bit longer for steering. With
light planes, flaps may be retracted so that the plane leaves the ground at a
higher speed than normal. Once the plane leaves the ground, the pilot adjusts
the controls to achieve co-ordinated flight.

> 2. In crosswind landings, it's recommended that one lands on only the
> upwind wheel. Since this would almost always tilt the upwind wing
> groundward, would there not be an engine strike? I'm especially
> thinking of aircraft like the 737 and A320...

Yes. In aircraft with engines under the wing, the plane is usually landed by
either landing sideways and allowing the gear to kick it straight or (more
usually) coming in at an angle and kicking the aircraft in line with the runway
by using the rudder just before touchdown. This latter method is called the
"crab and kick" method. There are several old videos floating around of 747s
landing at Hong Kong's old airport. In one, the plane obviously touches down at
at least a 20 degree angle to the runway. The amount of smoke from the tires is
impressive. In another, the plane banks just before touching down and loses an
engine when the engine hits the pavement.

> 3. How to slip an aircraft sideward? I'm visualizing a situation on
> final when a draft of air suddenly blows the aircraft a bit off-center
> and when it might be a bit late to try and bank the craft to get it
> back into proper alignment.

When you bank an aircraft and use the rudder to counter the yaw effect, it will
turn. If, however, you don't counter the yaw, it will slide sideways towards the
low wing. If you actually push the rudder in the opposite direction to enhance
yaw, the plane will fly sideways. This is a slip. One use for a slip is to keep
the plane lined up with the runway when a crosswind is trying to blow the plane
sideways. Another use is to increase the rate of descent if you're too high on
final.

The gusty wind situation you describe is usually handled by normal maneuvers
(such as a small S-turn) while using throttle to keep from touching down. In
extreme cases, the pilot aborts the landing and climbs back up to try again.
Slips are, however, one tool that a pilot can use to handle gusts, so it
wouldn't be unusual for a pilot to do so.

George Patterson
The desire for safety stands against every great and noble enterprise.

[G.R. Patterson III]

Ramapriya wrote:
>
> I could be wrong but I got the impression that the 707s made more noise
> than comparable-sized aircraft...

707s are old planes by now. Jet engines have gotten quieter over the years. Any
707 that still has the original engine design is going to be very loud and smoke
a lot on takeoff. Even if the engines have been replaced with newer designs,
they'll be noisier than a 727. They 707 also has four of them versus the 727's
three.

When I was working at Hartsfield in the late 70s, it amused me that I never once
saw a 707 land there, but I could count on seeing several DC-3s every day if I
were working a site that allowed me to see a runway. Ten years or so before
that, every article or column about the 707 called it a classic, with the
implication that they would be flying for decades, but they were gone by that
time and the old Gooney Birds were still trucking passengers.

George Patterson
The desire for safety stands against every great and noble enterprise.

[Morgans]

"Ramapriya" > wrote in message
oups.com...
> Bob Moore wrote:
> >
> > the crab at the last second before touchdown. Boeing said
> > that if one was not comfortable doing that, just touchdown in
> > the crab. Of course autoland approaches always use the crab
>
> Sorry for being naive here Bob, but does touching down with the nose
> not pointed down the center of the airstrip, which is what I presume
> would happen if you touched down in the crab, bust the wheels?

Think of it this way.

All that mass is moving straight down the runway, still pretty fast. It is
going to try to keep going straight pretty fast. The only thing to cause
enough stress on the gear to try to break the gear is the tires.

What happens when the tires first touch down? A big puff of smoke, as the
tires spin up to speed. Just a little bit of force involved to do that. It
would take a whole lot more force to make that big bird go sideways, right?
So what happens? The tires skid a bit sideways for a while, until the FO
(the captain wouldn't have screwed up by not kicking the crab out, right?
<g> ) wakes up and corrects to get the thing pointed straight down the
runway, right?

It has been my experience, from riding the heavy iron, that the combination
of a slightly low wing and kicking the crab out is what is used. I say that
only from observation, as it feels like one side hits, followed *very
quickly* by the other side landing. Sometimes, it does feel like you are
taking a quick ride towards the lights.
--
Jim ( I'm grading your landings, Captains) in NC :-)

[Don Hammer]

I'm an old B-707 engineer. Seems it was something like 7degrees wing
down and you got the cowl. Land gliders all the time with a slip to
keep from getting a wing tip. Kick out the slip just prior to
touchdown. One time the cross wind was high enough, I just landed
across the runway at an intersection.

Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
----------------------------------------------------------
http://www.usenet.com

[Cockpit Colin]

> > Sorry for being naive here Bob, but does touching down with the nose
> > not pointed down the center of the airstrip, which is what I presume
> > would happen if you touched down in the crab, bust the wheels?
>
> Certainly not good for light general aviation aircraft, but the
> Boeings seem to take it easily.


I recall a 747 Captain telling me of how the aircraft is designed to
withstand something like a crab into a 25 knot cross wind without kicking it
straight - said he did it once, and suspects the passengers in the rear of
the aircraft are still having their necks treated by a chiropractor!

Possibly a point worth noting is that when you "kick an aircraft straight"
you still have a considerable mass heading straight down the runway, and the
aircraft simply has too much enertia to accelerate laterally in the short
time between being "kicked straight" and touchdown. I know that some
disagree, but even in GA I tend to kick it straight at the last moment, but
add "more" opposite aileron to counter the adverse bank and drop the
upstream wing - works for me every time.

In talking with 757 Captains I'm told that the max angle of bank in landing
is something like 5 deg.

[[email protected]]

Bob Moore wrote:
> "Ramapriya" wrote
> > Sorry for being naive here Bob, but does touching down with the
nose
> > not pointed down the center of the airstrip, which is what I
presume
> > would happen if you touched down in the crab, bust the wheels?
>
> Certainly not good for light general aviation aircraft, but the
> Boeings seem to take it easily.
>

Unless you happen to be flying an Ercoupe, which is designed to land
crabbed in a crosswind. The gear is purposely beefed up for this
purpose. On most other GA aircraft, it's definitely not advisable.

On one of my very first lessons, I was on final following a Tomahawk
landing with a stiff crosswind. My instructor told me to watch the
Piper closely to see how the pilot corrected the crab just before
touchdown, to land the plane with the nose aligned with the runway.
Well, the (student) pilot didn't correct for the crosswind and touched
down while still in a crab. We watched the right gear leg fly off the
bottom of the wing and take out the right side of the horizontal
T-tail. The plane slid to a stop on it's right wing, with pieces of the
tail scattered over the runway. My instructor then informed me that I
had just learned a valuable lesson about crosswind landings at
relatively little expense to me.

John Galban=====>N4BQ (PA28-180)

[Cockpit Colin]

Was the cross wind from the left or the right?

> wrote in message
oups.com...
>
> Bob Moore wrote:
> > "Ramapriya" wrote
> > > Sorry for being naive here Bob, but does touching down with the
> nose
> > > not pointed down the center of the airstrip, which is what I
> presume
> > > would happen if you touched down in the crab, bust the wheels?
> >
> > Certainly not good for light general aviation aircraft, but the
> > Boeings seem to take it easily.
> >
>
> Unless you happen to be flying an Ercoupe, which is designed to land
> crabbed in a crosswind. The gear is purposely beefed up for this
> purpose. On most other GA aircraft, it's definitely not advisable.
>
> On one of my very first lessons, I was on final following a Tomahawk
> landing with a stiff crosswind. My instructor told me to watch the
> Piper closely to see how the pilot corrected the crab just before
> touchdown, to land the plane with the nose aligned with the runway.
> Well, the (student) pilot didn't correct for the crosswind and touched
> down while still in a crab. We watched the right gear leg fly off the
> bottom of the wing and take out the right side of the horizontal
> T-tail. The plane slid to a stop on it's right wing, with pieces of the
> tail scattered over the runway. My instructor then informed me that I
> had just learned a valuable lesson about crosswind landings at
> relatively little expense to me.
>
> John Galban=====>N4BQ (PA28-180)
>

[[email protected]]

Cockpit Colin wrote:
> Was the cross wind from the left or the right?
>

It was a right crosswind. It would appear that the gear was better
suited to withstand a side load from the outside (like the left main),
than the inside.

John Galban=====>N4BQ (PA28-180)

[Cockpit Colin]

That's the bit I can't figure out - in that scenario I would have thought
that the leg / tire (or a vector component thereof) would simply be dragged
behind the aircraft.

I've heard of tire marks on the underside of the wings on Tomahawks from
extremely hard landings - but with the mechanism still in tact - which would
make one think that the undercarriage was pretty sturdy.


> wrote in message
oups.com...
>
> Cockpit Colin wrote:
> > Was the cross wind from the left or the right?
> >
>
> It was a right crosswind. It would appear that the gear was better
> suited to withstand a side load from the outside (like the left main),
> than the inside.
>
> John Galban=====>N4BQ (PA28-180)
>

[G. Sylvester]

> On one of my very first lessons, I was on final following a Tomahawk
> landing with a stiff crosswind. My instructor told me to watch the
> Piper closely to see how the pilot corrected the crab just before
> touchdown, to land the plane with the nose aligned with the runway.
> Well, the (student) pilot didn't correct for the crosswind and touched
> down while still in a crab. We watched the right gear leg fly off the
> bottom of the wing and take out the right side of the horizontal
> T-tail. The plane slid to a stop on it's right wing, with pieces of the
> tail scattered over the runway. My instructor then informed me that I
> had just learned a valuable lesson about crosswind landings at
> relatively little expense to me.


YIKES! I presume you have never ever ever did what this guy did.
Did you thank your instructor for the days effective training?

Gerald

[David CL Francis]

On Sat, 25 Dec 2004 at 23:29:34 in message
>, Morgans >
wrote:

>It has been my experience, from riding the heavy iron, that the combination
>of a slightly low wing and kicking the crab out is what is used. I say that
>only from observation, as it feels like one side hits, followed *very
>quickly* by the other side landing. Sometimes, it does feel like you are
>taking a quick ride towards the lights.

I have a little book that describes in detail a 747 flight from Toronto
to Heathrow. An autoland is carried out at Heathrow. It describes how,
in the first stages of the landing, the aircraft is aligned with the
runway in a crosswind by heading slightly into the cross wind. At 500 ft
to go the auto-pilot changes to 'runway align' and the wing is lowered
on one side and the rudder keeps the aircraft aligned with the runway. I
understand that the maximum autoland crosswind is 25 knots.
--
David CL Francis

[[email protected]]

Cockpit Colin wrote:
> That's the bit I can't figure out - in that scenario I would have
thought
> that the leg / tire (or a vector component thereof) would simply be
dragged
> behind the aircraft.

It would have, had it stayed attached.
>
> I've heard of tire marks on the underside of the wings on Tomahawks
from
> extremely hard landings - but with the mechanism still in tact -
which would
> make one think that the undercarriage was pretty sturdy.

And there's the lesson. I've also seen Tomahawk landing gear that
had taken a tremendous beating, with no apparent damage. The
difference is that those landings, although hard, were pretty much in
line with the runway. When it comes to side loads, all bets are off
unless you're flying an Ercoupe.

John Galban=====>N4BQ (PA28-180)

[[email protected]]

G. Sylvester wrote:
>
> YIKES! I presume you have never ever ever did what this guy did.
<snip>

Of course not. I've seen those who will sometimes cheat a little on
the crosswind landing and touch down with a bit of crab. In a tricycle
geared plane, the plane will straighten itself out. I learned early on
that you don't mess around with side loads on the gear.
John Galban=====>N4BQ (PA28-180)

[Brian]

I have to agree that the gear on the Tomahawk is quite strong. I have
give nearly 400 hours of primary instruction in Tomahawks and find it
to handle Crosswinds better than many(most?) GA aircraft. But then I
seldom Crab for a cross wind prefering instead to side slip.

One would have to hit incredibly hard to break a Tomahawk gear off. On
the other hand I have seen some strange combinations of loads break
things that one would think would not be even close. Perhaps the
combination of a very hard landing and the side load would be enough to
do it. or perhaps the gear had previously been damanged and the hard
X-wind landing was enough to finish it.

Brian
CFIIG/ASEL