Bad landing

[Frank Whiteley]

This might make you feel better about a few of your landings.

http://www.youtube.com/watch?v=eamnTyfkUBY

Song is a bit off color.

[jcarlyle]

Man - that's terrible! That must be one really difficult plane to
land, or these guys must not have many hours of experience.

-john

Frank Whiteley wrote:
> This might make you feel better about a few of your landings.
>
> http://www.youtube.com/watch?v=eamnTyfkUBY
>
> Song is a bit off color.

[chipsoars]

On Mar 6, 12:28*pm, Frank Whiteley > wrote:
> This might make you feel better about a few of your landings.
>
> http://www.youtube.com/watch?v=eamnTyfkUBY
>
> Song is a bit off color.

Did they dig up Buster Keaton for this?

Chip F.

[Darryl Ramm]

On Mar 6, 9:49*am, jcarlyle > wrote:
> Man - that's terrible! That must be one really difficult plane to
> land, or these guys must not have many hours of experience.
>
> -john
>
> Frank Whiteley wrote:
> > This might make you feel better about a few of your landings.
>
> >http://www.youtube.com/watch?v=eamnTyfkUBY
>
> > Song is a bit off color.
>
>

After a altitude chamber ride at Beale AFB our class went and toured a
hanger and look at a U2 and Global Hawk. The U2 pilot was describing
it's landing qualities, how they are a handful in a crosswind, how you
have to keep flying them once they are on the ground etc. Some of the
power only pilots were trying to think what it would be like. Then
some of the glider pilots spoke up and the U2 pilot agreed with
something like "oh wow some of you guys are glider pilots, yes it is
like landing a big glider with bad visibility". Some of the U2 pilots
at Beale fly gliders, the ones I've seen flying seem to have no
trouble greasing on an ASK-21.

Darryl

[bildan]

On Mar 6, 11:14*am, Darryl Ramm > wrote:
> On Mar 6, 9:49*am, jcarlyle > wrote:
>
> > Man - that's terrible! That must be one really difficult plane to
> > land, or these guys must not have many hours of experience.
>
> > -john
>
> > Frank Whiteley wrote:
> > > This might make you feel better about a few of your landings.
>
> > >http://www.youtube.com/watch?v=eamnTyfkUBY
>
> > > Song is a bit off color.
>
> After a altitude chamber ride at Beale AFB our class went and toured a
> hanger and look at a U2 and Global Hawk. The U2 pilot was describing
> it's landing qualities, how they are a handful in a crosswind, how you
> have to keep flying them once they are on the ground etc. Some of the
> power only pilots were trying to think what it would be like. Then
> some of the glider pilots spoke up and the U2 pilot agreed with
> something like *"oh wow some of you guys are glider pilots, yes it is
> like landing a big glider with bad visibility". Some of the U2 pilots
> at Beale fly gliders, the ones I've seen flying seem to have no
> trouble greasing on an ASK-21.
>
> Darryl

Not unusual transition issues. Maybe this is why the USAFA is high on
flying gliders.

Typical power pilots (well some of them anyway) think there's an FAR
somewhere that makes using the rudder illegal. They also think you
can stop flying the airplane when you feel the wheels touch the runway
- "because then you're a car". Believe it or not, I've heard CFI's
teaching exactly this.

[Bob Kuykendall]

On Mar 6, 10:14*am, Darryl Ramm > wrote:
> ...Some of the power only pilots were trying to think
> what it would be like...

Of course, the Powers only pilots already know...

[Darryl Ramm]

On Mar 6, 12:14*pm, Bob Kuykendall > wrote:
> On Mar 6, 10:14*am, Darryl Ramm > wrote:
>
> > ...Some of the power only pilots were trying to think
> > what it would be like...
>
> Of course, the Powers only pilots already know...

Oh Kuykendall humor. Where is that suicide pin. :-)

Darryl

[Chris Reed[_2_]]

Frank Whiteley wrote:
> This might make you feel better about a few of your landings.
>
> http://www.youtube.com/watch?v=eamnTyfkUBY
>
> Song is a bit off color.

Even those landings where the rudder was used didn't seem to have much
rudder *to* use, nor did the rudder seem to make a lot of difference to
where the aircraft was pointing.

That plus, apparently, no aileron control after touchdown, plus the fact
that full flap gives about the same float as a no airbrake landing in a
conventional glider, suggests this is rather a handful.

Would the aerodynamicists know whether these characteristics result from
optimisation for high altitude flight?

[Larry Goddard]

Hell, even the chase cars were spinning out of control!!!!!! Check it
out @ 2:17

"chipsoars" > wrote in message
:

> On Mar 6, 12:28 pm, Frank Whiteley > wrote:
> > This might make you feel better about a few of your landings.
> >
> > http://www.youtube.com/watch?v=eamnTyfkUBY
> >
> > Song is a bit off color.
>
> Did they dig up Buster Keaton for this?
>
> Chip F.

[Craig[_2_]]

On Mar 6, 2:25*pm, Chris Reed > wrote:
> Frank Whiteley wrote:
> > This might make you feel better about a few of your landings.
>
> >http://www.youtube.com/watch?v=eamnTyfkUBY
>
> > Song is a bit off color.
>
> Even those landings where the rudder was used didn't seem to have much
> rudder *to* use, nor did the rudder seem to make a lot of difference to
> where the aircraft was pointing.
>
> That plus, apparently, no aileron control after touchdown, plus the fact
> that full flap gives about the same float as a no airbrake landing in a
> conventional glider, suggests this is rather a handful.
>
> Would the aerodynamicists know whether these characteristics result from
> optimisation for high altitude flight?

Just Kelly Johnson's idea of a sick joke ;-)

Craig

[kestrel19]

On Mar 6, 10:49*am, jcarlyle > wrote:
> Man - that's terrible! That must be one really difficult plane to
> land, or these guys must not have many hours of experience.
>
> -john
>
Note sure of present day qualifications, but IIRC, back in the 1980's
I was told that it took 1500 hours of stick time to get a shot and
three tries at landing to get accepted. You had to have the touch.

A bent wing meant a museum piece as the spars were machined from a
single billet of aluminum.

Frank

[[email protected]]

Maybe they should have gone to negative flaps after touchdown!

[[email protected]]

On Mar 7, 8:56*am, wrote:
> Maybe they should have gone to negative flaps after touchdown!

We need to do that with our Nimbus 3DT unless you wantto go into the
dirt!

[Jim Beckman[_2_]]

At 17:49 06 March 2009, jcarlyle wrote:
>Man - that's terrible! That must be one really difficult plane to
>land, or these guys must not have many hours of experience.

Notice that most of these landings are happening in the two-seat trainer
version of the U-2, so yes, the pilots probably didn't have much in the
way of experience.

Jim Beckman

[Lew Hartswick]

Frank Whiteley wrote:
> This might make you feel better about a few of your landings.
>
> http://www.youtube.com/watch?v=eamnTyfkUBY
>

Never saw one land but the one I saw take off at Bien Hoa
was sure a pretty picture. A few of those sequences were
during takeoff, still had the wing wheels on.
...lew...

[KevinFinke]

This months Flying Magazine has a really good article on flying the
U2. They mention a number of factors that contribute to it's
difficulty in landing. It's a good read. I recommend checking it out.

Any one notice how little dihedral the airplane has? I'm sure that
doesn't help at all. And what about the spoilers? They look smaller
than a Schweizer 1-19....

-Kevin

[Eric Greenwell]

KevinFinke wrote:
> This months Flying Magazine has a really good article on flying the
> U2. They mention a number of factors that contribute to it's
> difficulty in landing. It's a good read. I recommend checking it out.
>
> Any one notice how little dihedral the airplane has? I'm sure that
> doesn't help at all. And what about the spoilers? They look smaller
> than a Schweizer 1-19....

How does the dihedral affect the landing characteristics?

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* Sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[sisu1a]

> How does the dihedral affect the landing characteristics?
>

1. Roll stability (or lack thereof)
2. Wingtip clearance

Shooting from the hip,
-Paul

[KevinFinke]

Paul, that's exactly what I was thinking. In watching the videos, it
looked like the aileron effectiveness was very poor, so if a wing
started rolling, it just kept going. That combined with the low tip
clearance meant that the airplane looked very prone to easy ground
looping. If the airplane had better roll stability, I think it would
be easier to land.

In the flying article, they comment that in order to save weight, the
airplane has un-boosted controls. The plane really only lightens up in
control forces at it's design mission. The rest of the time, it takes
a lot of strength and force to move them. Can't imagine that's very
easy after flying for a long mission, now I have to do a strength
workout just to land.

-Kevin

[Eric Greenwell]

sisu1a wrote:
>> How does the dihedral affect the landing characteristics?
>>
>
> 1. Roll stability (or lack thereof)

Why do you want it to be "stable"? Doesn't that prevent you from easily
holding it in a slip? My thought is roll response is important, not
stability.

> 2. Wingtip clearance

No argument there!


--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* Sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[bildan]

On Mar 6, 3:25*pm, Chris Reed > wrote:
> Frank Whiteley wrote:
> > This might make you feel better about a few of your landings.
>
> >http://www.youtube.com/watch?v=eamnTyfkUBY
>
> > Song is a bit off color.
>
> Even those landings where the rudder was used didn't seem to have much
> rudder *to* use, nor did the rudder seem to make a lot of difference to
> where the aircraft was pointing.
>
> That plus, apparently, no aileron control after touchdown, plus the fact
> that full flap gives about the same float as a no airbrake landing in a
> conventional glider, suggests this is rather a handful.
>
> Would the aerodynamicists know whether these characteristics result from
> optimisation for high altitude flight?

I think the rudder is adequate - people do fly it successfully.
Rather, what I saw was a pilot trying to 'steer' with aileron. If the
rudder was used, it was far too late to be effective.

Indeed, flap retraction once on the ground would have helped but how
slowly do they retract? If they are hydraulic or electric, it might
take more time than they have after touchdown.

There are two typical 'gotchas' for transitioning power pilots. They
tend to forget that there is only one wheel and not three so let a
glider tip over before responding and they are usually not too quick
with the rudder. I think I saw that in the video too.

[KevinFinke]

Eric,

For the purpose of the discussion, let's separate stability from
maneuverability. The two are coupled in that a very stable design will
require large control surfaces to overcome stabilizing forces.

I would think for ease of landing you would want good stability. We're
all aware of how gusts and changing winds have an affect on us during
landing. Stability is essentially a measure of how quickly an an
aircraft will return to it's static state after an upset. If the
stability is high, it would return to this state quickly, and if it is
low, it won't. If it is unstable, it will diverge and get worse. I
can only imagine that would help during landing. Rather than having to
correct for each and every upset during approach, the pilot could
focus more of their tasks on execution rather than correction. Does
that seem a reasonable hypothesis?

However, too much stability would be bad as well. There would have to
be a balance. Perhaps because the controls are non-boosted, and it
seems that an effort was made to properly balance the airplane for
it's mission. At mach 0.71@ 70,000 feet or greater, pilots report that
it's a delight to fly and handle at these conditions. I would suspect,
that the vast difference in these two extremes, probably resulted in
some compromises to it's stability and maneuverability during landing.
Of course, this is all speculation on my part because I was not
involved with the design, but it seems reasonable and fits with my
understanding of stability and control.

-Kevin

PS We've had some soarable weather here on the West side of the
cascades, but I'm itching to start flying in Ephrata. The SGC is
hosting a 3 day racing encampment during Memorial day. Any plans to
attend? I've met you before on a couple of occasions, but haven't sat
down and talked at length. You're one of the local resources of
knowledge that I would enjoy learning from.

[Eric Greenwell]

KevinFinke wrote:
> Eric,
>
> For the purpose of the discussion, let's separate stability from
> maneuverability. The two are coupled in that a very stable design will
> require large control surfaces to overcome stabilizing forces.
>
> I would think for ease of landing you would want good stability. We're
> all aware of how gusts and changing winds have an affect on us during
> landing. Stability is essentially a measure of how quickly an an
> aircraft will return to it's static state after an upset. If the
> stability is high, it would return to this state quickly, and if it is
> low, it won't.

Would you agree it's also a indication of much it will react to upsets?
Generally, I think, the more stable the aircraft, the more it will react
to gusts. So, an aircraft with mild/neutral stability won't react to the
gust, and there will be nothing to correct. I think that's better in
gusty conditions, because there is always another gust, so if aircraft
is "stable", you spend a lot of time correcting.

> If it is unstable, it will diverge and get worse.

Well, maybe, except you have the pilot to damp the motions, easy to do
if the divergence is slow. And, at landing speeds, things are happening
slowly.

> I
> can only imagine that would help during landing. Rather than having to
> correct for each and every upset during approach, the pilot could
> focus more of their tasks on execution rather than correction. Does
> that seem a reasonable hypothesis?

I'm still thinking a mildly/neutrally stable aircraft is going to be
easier to handle in gusts. I don't know how stable the U2 is, but I
don't see how we can tell, just by looking at the dihedral. There are
other factors, like the amount of sweep back and the effective rudder
size, so I fussing about picking just dihedral as an important factor.
>
> However, too much stability would be bad as well. There would have to
> be a balance. Perhaps because the controls are non-boosted, and it
> seems that an effort was made to properly balance the airplane for
> it's mission. At mach 0.71@ 70,000 feet or greater, pilots report that
> it's a delight to fly and handle at these conditions. I would suspect,
> that the vast difference in these two extremes, probably resulted in
> some compromises to it's stability and maneuverability during landing.
> Of course, this is all speculation on my part because I was not
> involved with the design, but it seems reasonable and fits with my
> understanding of stability and control.

My guess is it has so much yaw inertia (and maybe roll inertia) and slow
response (that's the maneuverability compromise, I'm sure) to both
rudder and aileron during landing, that the pilots were way behind the
aircraft. That's typical of power pilots used to flying short wing
aircraft with good response to control inputs at landing speeds. I
suspect that's a more likely explanation than the effect of dihedral.

> -Kevin
>
> PS We've had some soarable weather here on the West side of the
> cascades, but I'm itching to start flying in Ephrata. The SGC is
> hosting a 3 day racing encampment during Memorial day. Any plans to
> attend? I've met you before on a couple of occasions, but haven't sat
> down and talked at length. You're one of the local resources of
> knowledge that I would enjoy learning from.

We're planning a safari to Golden, BC, the Memorial Day week and
weekend, but we plan to come up to fly during (not in) the contest for a
couple days. We'll see you then!

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* Sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[kestrel19]

On Mar 7, 12:24*pm, KevinFinke > wrote:
> Paul, that's exactly what I was thinking. In watching the videos, it
> looked like the aileron effectiveness was very poor, so if a wing
> started rolling, it just kept going. That combined with the low tip
> clearance meant that the airplane looked very prone to easy ground
> looping. If the airplane had better roll stability, I think it would
> be easier to land.
>
> In the flying article, they comment that in order to save weight, the
> airplane has un-boosted controls. The plane really only lightens up in
> control forces at it's design mission. The rest of the time, it takes
> a lot of strength and force to move them. Can't imagine that's very
> easy after flying for a long mission, now I have to do a strength
> workout just to land.
>
> -Kevin

IIRC, the only 'boost' control was the vernier control on the engine
exhaust nozzle. Controllable to within 1.5deg F.

Frank