Piper Cub Vs F-15

[Emilio]

It is hard to believe that F-15 can fly formation with Piper Cub.

http://www.pipercubforum.com/intercep.htm

Do F-15 fly by wire system prevent the aircraft from stalling at that low
speed? Last time I saw an aircraft with fly by wire system did such a
stunt, Airbus plowed right in to the forest at the end of the forest!

Emilio.

[Ed Rasimus]

On Tue, 29 Jun 2004 11:13:15 -0500, "Emilio" >
wrote:

>It is hard to believe that F-15 can fly formation with Piper Cub.
>
>http://www.pipercubforum.com/intercep.htm
>
>Do F-15 fly by wire system prevent the aircraft from stalling at that low
>speed? Last time I saw an aircraft with fly by wire system did such a
>stunt, Airbus plowed right in to the forest at the end of the forest!
>
>Emilio.
>

First, lets note that a Piper Cub (usually a J-3) is one thing and a
Cessna 172 is another. The J-3 would be cruising at 65-75 MPH while
the 172 might be doing closer to 120-140.

Since the Eagle can come over the fence on landing at 130 KIAS or
thereabout, it isn't too tough to dump flaps and throw up the barn
door, then load up the big engines to hang on them at low speed. Not
comfy, but easily doable.


Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
Smithsonian Institution Press
ISBN #1-58834-103-8

[Ron]

>From: "Emilio"
>Date: 6/29/2004 12:13 PM Eastern Daylight Time
>Message-id: >
>
>It is hard to believe that F-15 can fly formation with Piper Cub.
>
>http://www.pipercubforum.com/intercep.htm
>
>Do F-15 fly by wire system prevent the aircraft from stalling at that low
>speed? Last time I saw an aircraft with fly by wire system did such a
>stunt, Airbus plowed right in to the forest at the end of the forest!
>
>Emilio.

Its actuallly about a C-172 getting intercepted, about a 110 knot airplane.
Still pretty slow though.
Guess we would need one of the eagle drivers to chime in...


Ron
PA-31T Cheyenne II
Maharashtra Weather Modification Program
Pune, India

[John Mullen]

"Emilio" > wrote in message
...
> It is hard to believe that F-15 can fly formation with Piper Cub.
>
> http://www.pipercubforum.com/intercep.htm
>
> Do F-15 fly by wire system prevent the aircraft from stalling at that low
> speed? Last time I saw an aircraft with fly by wire system did such a
> stunt, Airbus plowed right in to the forest at the end of the forest!

That was more to do with the poor planning and complacency of the pilots
than the FBW system.

John

[Steven P. McNicoll]

"Ed Rasimus" > wrote in message
...
>
> First, lets note that a Piper Cub (usually a J-3) is one thing and a
> Cessna 172 is another.
>

Actually, I think you'll find a Piper Cub is always a J-3.

[Ed Rasimus]

On Tue, 29 Jun 2004 17:28:43 GMT, "Steven P. McNicoll"
> wrote:

>
>"Ed Rasimus" > wrote in message
...
>>
>> First, lets note that a Piper Cub (usually a J-3) is one thing and a
>> Cessna 172 is another.
>>
>
>Actually, I think you'll find a Piper Cub is always a J-3.
>
While a "Piper Cub" may not be a Taylorcraft or an Aeronca, I've seen
it applied quite comfortably to a J-4 and (IIRC) J-6. They probably
had a proper corporate nomenclature, but as canvas-sided,
tail-dragging, Continental-powered, products of Piper Aircraft, they
pretty much got stuck with the moniker.

I got my first flying lessons and solo hours in a J-3 and wish
fervently that I owned one today. Not much good for travel, but it was
easy to "dance the sky" and the yellow aero-doped wings were pretty
easy to "laughter-silver."

Got my first (student) license supension and grounding flying a PA-22
Colt. And passed my Private license check flight in a PA-18 Super
Cub--damn complex, it had a radio and flaps!


Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
Smithsonian Institution Press
ISBN #1-58834-103-8

[Mike]

"John Mullen" > wrote in message
...
> "Emilio" > wrote in message
> ...
> > It is hard to believe that F-15 can fly formation with Piper Cub.
> >
> > http://www.pipercubforum.com/intercep.htm
> >
> > Do F-15 fly by wire system prevent the aircraft from stalling at that
low
> > speed? Last time I saw an aircraft with fly by wire system did such a
> > stunt, Airbus plowed right in to the forest at the end of the forest!
>
> That was more to do with the poor planning and complacency of the pilots
> than the FBW system.
>
> John
>
>

The pilots had a) ignored the 'low altitude' warning, b) thought they were
flying at 100 feet rather than the actual 30, and c) hadn't anticipated or
allowed for the delay in pushing the throttle and the engines actually
responding.

[Greasy Rider @ Invalid.com]

On Tue, 29 Jun 2004 11:53:35 -0600, Ed Rasimus
> proclaimed:

>Not much good for travel, but it was
>easy to "dance the sky" and the yellow aero-doped wings were pretty
>easy to "laughter-silver."

"laughter-silver." is a term I'm not familiar with. Care to enlighten
me?

[George Z. Bush]

"Emilio" > wrote in message
...

> It is hard to believe that F-15 can fly formation with Piper Cub.

> http://www.pipercubforum.com/intercep.htm


Only for the split second it takes for the Eagle to overrun the Pooper. At all
other times, it's either rapidly overtaking or rapidly leaving the Pooper in its
dust. (^-^)))

George Z.

[Alan Dicey]

Emilio wrote:
>
> Do F-15 fly by wire system prevent the aircraft from stalling at that low
> speed? Last time I saw an aircraft with fly by wire system did such a
> stunt, Airbus plowed right in to the forest at the end of the forest!
>

The F15 does not have what avionics people think of as fly-by-wire. In
fly-by-wire the control surfaces are moved by the computer alone, which
integrates control inputs (pilots suggestions) with the aircrafts
position in the flight envelope (the sensed environment). In
fly-by-wire there is no mechanical connection between the pilot and the
control surfaces. The F-15 has hydromechanical connections between the
pilots controls and the ailerons, stabilators and rudders.

What the F-15 does have is a stability augmentation system.

http://www.globalsecurity.org/military/systems/aircraft/f-15e.htm

The first production fly-by-wire aircraft was the F-16.

[John R Weiss]

"Steven P. McNicoll" > wrote...
>
> Actually, I think you'll find a Piper Cub is always a J-3.

According to http://www.pipercubforum.com/whats.htm, a "Piper Cub" could be
a J-2, J-3, J-4, J-5, or PA-11. Closely related to the Cub are the PA-12,
PA-14, and PA-18.

[Ed Rasimus]

On Tue, 29 Jun 2004 18:40:52 GMT, Greasy Rider @ Invalid.com wrote:

>On Tue, 29 Jun 2004 11:53:35 -0600, Ed Rasimus
> proclaimed:
>
>>Not much good for travel, but it was
>>easy to "dance the sky" and the yellow aero-doped wings were pretty
>>easy to "laughter-silver."
>
>"laughter-silver." is a term I'm not familiar with. Care to enlighten
>me?

Refer to John Gillespie Magee.


Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
Smithsonian Institution Press
ISBN #1-58834-103-8

[Greasy Rider @ Invalid.com]

On Tue, 29 Jun 2004 13:34:59 -0600, Ed Rasimus
> proclaimed
obliquely :

>John Gillespie Magee

Ain't Google great?

[B2431]

>Subject: Piper Cub Vs F-15
>From: "Emilio"
>Date: 6/29/2004 11:13 AM Central Daylight Time
>Message-id: >
>
>It is hard to believe that F-15 can fly formation with Piper Cub.
>
>http://www.pipercubforum.com/intercep.htm
>
>Do F-15 fly by wire system prevent the aircraft from stalling at that low
>speed? Last time I saw an aircraft with fly by wire system did such a
>stunt, Airbus plowed right in to the forest at the end of the forest!
>
>Emilio.

The article is from ANN which automatically makes the details automatically
suspect. If it was written my Jim "Capt Zoom" Campbell it is near fiction even
based on an actual event. For a little overview see:
http://mywebpages.comcast.net/ousterj/zoom.html

What tripped my BS alarm was the C-172's pilot's first hint he wasn't alone was
the "smell of burning paint." Unless the guy was stone deaf would he not have
heard the F-15 if it were close enough to smell? I'm am not saying the event
didn't occur, just not the way it was written.

Dan, U.S. Air Force, retired

[John Mullen]

"Mike" > wrote in message
...
> "John Mullen" > wrote in message
> ...
> > "Emilio" > wrote in message
> > ...
> > > It is hard to believe that F-15 can fly formation with Piper Cub.
> > >
> > > http://www.pipercubforum.com/intercep.htm
> > >
> > > Do F-15 fly by wire system prevent the aircraft from stalling at that
> low
> > > speed? Last time I saw an aircraft with fly by wire system did such a
> > > stunt, Airbus plowed right in to the forest at the end of the forest!
> >
> > That was more to do with the poor planning and complacency of the pilots
> > than the FBW system.
> >
> > John
> >
> >
>
> The pilots had a) ignored the 'low altitude' warning, b) thought they were
> flying at 100 feet rather than the actual 30, and c) hadn't anticipated or
> allowed for the delay in pushing the throttle and the engines actually
> responding.

They had also lined up on the wrong runway for the display they were doing,
and disabled the alpha floor function (?) which normally protects the
plane's speed.

A common theme in a lot of these modern crashes is the immense over reliance
pilots place in the automated systems.

If you point the plane at the ground and turn off the engines, it will still
crash. A sobering thought.

John

[Paul J. Adam]

In message >,
writes
>"laughter-silver." is a term I'm not familiar with. Care to enlighten
>me?

John Gillespie McGee's poem, "High Flight", refers to 'laughter-silvered
wings' while describing the sheer joy of flying.

--
He thinks too much: such men are dangerous.
Julius Caesar I:2

Paul J. Adam MainBox<at>jrwlynch[dot]demon{dot}co(.)uk

[Steven P. McNicoll]

"Ed Rasimus" > wrote in message
...
>
> While a "Piper Cub" may not be a Taylorcraft or an Aeronca, I've seen
> it applied quite comfortably to a J-4 and (IIRC) J-6. They probably
> had a proper corporate nomenclature, but as canvas-sided,
> tail-dragging, Continental-powered, products of Piper Aircraft, they
> pretty much got stuck with the moniker.
>

There are those who use "Piper Cub" to describe any light aircraft, and some
refer to all of the long-wing rag-and-tube Pipers as Cubs.

My earlier statement, that a Piper Cub is always a J-3, was not quite
correct. While all of the Cubs prior to the J-3 (E-2, F-2, H-2, and J-2)
were certificated by Taylor Aircraft Company, a few J-2s were built after
the company moved from Bradford to Lock Haven and became Piper. The J-3
supplanted the J-2 six months after the move.

There were later variants as well, but they weren't just called "Cub". The
J-4 was called the "Cub Coupe", the J-5 the "Cub Cruiser", and the PA-18 the
"Super Cub".


>
> I got my first flying lessons and solo hours in a J-3 and wish
> fervently that I owned one today. Not much good for travel, but it was
> easy to "dance the sky" and the yellow aero-doped wings were pretty
> easy to "laughter-silver."
>

I own an Aeronca 7AC, similar performance to a J-3 but you get to sit up
front where you can see.

[Steven P. McNicoll]

<Greasy Rider @ Invalid.com> wrote in message
...
>
> "laughter-silver." is a term I'm not familiar with. Care to enlighten
> me?
>

It's from the poem "High Flight".

Oh! I have slipped the surly bonds of Earth
And danced the skies on laughter-silvered wings;
Sunward I've climbed, and joined the tumbling mirth
Of sun-split clouds, - and done a hundred things
You have not dreamed of - wheeled and soared and swung
High in the sunlit silence. Hov'ring there,
I've chased the shouting wind along, and flung
My eager craft through footless halls of air. . . .

Up, up the long, delirious burning blue
I've topped the wind-swept heights with easy grace
Where never lark, or ever eagle flew -
And, while with silent, lifting mind I've trod
The high untresspassed sanctity of space,
Put out my hand, and touched the face of God.

[Steven P. McNicoll]

"John R Weiss" > wrote in message
news:MijEc.130736$HG.83348@attbi_s53...
>
> According to http://www.pipercubforum.com/whats.htm, a "Piper Cub"
> could be a J-2, J-3, J-4, J-5, or PA-11. Closely related to the Cub are
> the PA-12, PA-14, and PA-18.
>

A few J-2s were built by Piper, the majority were built by Taylor. The J-4
was called the "Cub Coupe", the J-5 was called the "Cub Cruiser", the PA-11
was called the "Cub Special", the PA-12 was called the "Super Cruiser", the
PA-14 was called the "Family Cruiser", and the PA-18 was called the "Super
Cub".

[Eunometic]

Alan Dicey > wrote in message >...
> Emilio wrote:
> >
> > Do F-15 fly by wire system prevent the aircraft from stalling at that low
> > speed? Last time I saw an aircraft with fly by wire system did such a
> > stunt, Airbus plowed right in to the forest at the end of the forest!
> >
>
> The F15 does not have what avionics people think of as fly-by-wire. In
> fly-by-wire the control surfaces are moved by the computer alone, which
> integrates control inputs (pilots suggestions) with the aircrafts
> position in the flight envelope (the sensed environment). In
> fly-by-wire there is no mechanical connection between the pilot and the
> control surfaces. The F-15 has hydromechanical connections between the
> pilots controls and the ailerons, stabilators and rudders.
>
> What the F-15 does have is a stability augmentation system.
>
> http://www.globalsecurity.org/military/systems/aircraft/f-15e.htm
>
> The first production fly-by-wire aircraft was the F-16.

Concord actually. They even wanted to put sidearm controllers on it.

[Ron]

> What the F-15 does have is a stability augmentation system.
>>
>> http://www.globalsecurity.org/military/systems/aircraft/f-15e.htm
>>
>> The first production fly-by-wire aircraft was the F-16.
>
>Concord actually. They even wanted to put sidearm controllers on it.
>

F-16 was the first with a DIGITAL FBW. I think Corcorde, and possibly F-111
too had analog systems.


Ron
PA-31T Cheyenne II
Maharashtra Weather Modification Program
Pune, India

[Peter Stickney]

In article >,
(Eunometic) writes:
> Alan Dicey > wrote in message >...
>> Emilio wrote:
>> >
>> > Do F-15 fly by wire system prevent the aircraft from stalling at that low
>> > speed? Last time I saw an aircraft with fly by wire system did such a
>> > stunt, Airbus plowed right in to the forest at the end of the forest!
>> >
>>
>> The F15 does not have what avionics people think of as fly-by-wire. In
>> fly-by-wire the control surfaces are moved by the computer alone, which
>> integrates control inputs (pilots suggestions) with the aircrafts
>> position in the flight envelope (the sensed environment). In
>> fly-by-wire there is no mechanical connection between the pilot and the
>> control surfaces. The F-15 has hydromechanical connections between the
>> pilots controls and the ailerons, stabilators and rudders.
>>
>> What the F-15 does have is a stability augmentation system.
>>
>> http://www.globalsecurity.org/military/systems/aircraft/f-15e.htm
>>
>> The first production fly-by-wire aircraft was the F-16.
>
> Concord actually. They even wanted to put sidearm controllers on it.

F-111, actually. And, perhaps the A-5 Vigilante, depending on how you
want to define FBW.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[Bill Shatzer]

"Steven P. McNicoll" ) writes:
> "Ed Rasimus" > wrote in message
> ...

>> First, lets note that a Piper Cub (usually a J-3) is one thing and a
>> Cessna 172 is another.

> Actually, I think you'll find a Piper Cub is always a J-3.

Wasn't there a J-5 version as well?

--


"Cave ab homine unius libri"

[Jim Thomas]

This led me to go find my F-15A-1, circa 1975. Level flight, 0 bank,
military thrust, gear & flaps down, sea level stall speed (defined as
30 deg AOA) was about 100 KIAS. Final approach speed under those
conditions was 143 KIAS. So, assuming the numbers haven't changed much
for the F-15C/D, staying with a 110-120 KIAS Cessna would be sporty,
but doable.

Jim Thomas


> >Emilio.
>
> Its actuallly about a C-172 getting intercepted, about a 110 knot airplane.
> Still pretty slow though.
> Guess we would need one of the eagle drivers to chime in...
>
>
> Ron
> PA-31T Cheyenne II
> Maharashtra Weather Modification Program
> Pune, India

[Nemo l'Ancien]

>
>
>
>
Your comment about Airbus is quite out... The fact you are speaking
about is coming from a direct mistake of a pilot stupid enough to
execute a non planned demo, with passengers on board, over an un
prepared field...
And this aircraft is not a fighter...

[Cub Driver]

That particular case was a 172.

F-16s were evidently dispatched to intercept me while I was bring a
Cub home on 9/11. Happily I was on the ground before they located me.
www.pipercubforum.com/defcon.htm

Which is what sparked my interest in the matter. I hope you hear from
an F-15/F-16 driver who has been obliged to make such an interception.

all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

[Cub Driver]

On Tue, 29 Jun 2004 10:19:45 -0600, Ed Rasimus
> wrote:

>The J-3 would be cruising at 65-75 MPH

In my case, 60 knots on the nose. Makes the chart work a breeze :)

(The wind tends to spoil things, however. I never know how much until
I put a GPS on the front seat-back.)

all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

[Cub Driver]

On 29 Jun 2004 19:45:36 GMT, (B2431) wrote:

>What tripped my BS alarm was the C-172's pilot's first hint he wasn't alone was
>the "smell of burning paint." Unless the guy was stone deaf would he not have
>heard the F-15 if it were close enough to smell? I'm am not saying the event
>didn't occur, just not the way it was written.

That's the pilot talking, not the reporter.

Personally, I read the Aero-News Propwash every morning and find it at
least as informative as this newsgroup, and the opinions probably less
biased.

all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

[Steven P. McNicoll]

"Bill Shatzer" > wrote in message
...
>
> Wasn't there a J-5 version as well?
>

The J-5 was the "Cub Cruiser".

[Eunometic]

"Peter Stickney" > wrote in message
...
> In article >,
> (Eunometic) writes:
> > Alan Dicey > wrote in message
>...
> >> Emilio wrote:
> >> >
> >> > Do F-15 fly by wire system prevent the aircraft from stalling
at that low
> >> > speed? Last time I saw an aircraft with fly by wire system did
such a
> >> > stunt, Airbus plowed right in to the forest at the end of the
forest!
> >> >
> >>
> >> The F15 does not have what avionics people think of as
fly-by-wire. In
> >> fly-by-wire the control surfaces are moved by the computer alone,
which
> >> integrates control inputs (pilots suggestions) with the aircrafts
> >> position in the flight envelope (the sensed environment). In
> >> fly-by-wire there is no mechanical connection between the pilot
and the
> >> control surfaces. The F-15 has hydromechanical connections
between the
> >> pilots controls and the ailerons, stabilators and rudders.
> >>
> >> What the F-15 does have is a stability augmentation system.
> >>
> >> http://www.globalsecurity.org/military/systems/aircraft/f-15e.htm
> >>
> >> The first production fly-by-wire aircraft was the F-16.
> >
> > Concord actually. They even wanted to put sidearm controllers on
it.
>
> F-111, actually. And, perhaps the A-5 Vigilante, depending on how
you
> want to define FBW.
>

This is a cut and paste job. However I suspect we could go back to
before even 1956.


A few quotes from the relevant chapter from Bill Gunston's book
"Avionics":

The author was privileged to have flown in about 1956
in the world's first FBW aircraft, the Tay-engined
Viscount 663 which had been bailed to Boulton Paul to
support the Valiant bomber programme. Through primitive,
the system was true pioneering. The right-hand seat was
'all electric', with wiper potentiometers transmitting
pilot demands along dual electrical channels (I believe
one used 28V DC and the other, basically identical, used
110V AC), with a feedback potentiometer at each powered
surface.

[snip]

In 1962 the basic design of Concorde was settled, one of
the Anglo-French choices being to use fully powered elevons
and rudder with electrical signalling. (Further it is
added the the jet inlet control system is also FBW.)

[snip]

In 1972 the United States got into the act, most notably
with the NACA F-8C Crusader, which in May 1972 made the
first FBW flight without mechanical reversion. This
aircraft had simplex digital control, the first wholly
non-analog aircraft in the world, the standby system
being triplex analog.

[snip]

These encouraging results confirmed Panavia in their
much earlier (1968) choice if triplex analog for Tornado,
and, apart from Concorde, this was the first production
FBW aircraft in the world. [snip] FBW links feed the
computerised outputs to the tailerons, spoilers and
rudder, with mechanical reversion for the tailerons only.

[snip]

Tornado first flew in 1974, and the same year saw the
first flight of the General Dynamics YF-16. [snip] Its
FBW system was the first in the world to have no
reversionary system whatever.

[Ed Rasimus]

On Wed, 30 Jun 2004 05:28:07 -0400, Cub Driver
> wrote:

>On Tue, 29 Jun 2004 10:19:45 -0600, Ed Rasimus
> wrote:
>
>>The J-3 would be cruising at 65-75 MPH
>
>In my case, 60 knots on the nose. Makes the chart work a breeze :)
>
>(The wind tends to spoil things, however. I never know how much until
>I put a GPS on the front seat-back.)

How gauche. Next you'll be putting a chrome wire through the fuel cap
instead of an old coat hangar. What then, a fiberglass float instead
of a doped cork?


Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
Smithsonian Institution Press
ISBN #1-58834-103-8

[Mike Marron]

(Jim Thomas) wrote:

>This led me to go find my F-15A-1, circa 1975. Level flight, 0 bank,
>military thrust, gear & flaps down, sea level stall speed (defined as
>30 deg AOA) was about 100 KIAS. Final approach speed under those
>conditions was 143 KIAS. So, assuming the numbers haven't changed much
>for the F-15C/D, staying with a 110-120 KIAS Cessna would be sporty,
>but doable.

My commercial pilot log shows that in the chaotic days following 9/11
(29 October, 2001) while cruising along in a Cessna 210L at 160 kts.
or so I was intercepted by an F-15 near Miami's Turkey Point nuke
powerplant. However, since I was on an IFR flight plan and talking to
Miami Center, they handed me off to Homestead AFB who gave me
a heads up. "Shark XX" zipped by lickity split about 50-75 yards in
front of me at the same altitude and perpindicular to my flightpath
then disappeared over the Atlantic as quickly as it appeared.

[Mortimer Schnerd, RN]

Ed Rasimus wrote:
> How gauche. Next you'll be putting a chrome wire through the fuel cap
> instead of an old coat hangar. What then, a fiberglass float instead
> of a doped cork?


People put dope on the cork?




--
Mortimer Schnerd, RN


http://www.mortimerschnerd.com

[Ed Rasimus]

On Wed, 30 Jun 2004 11:18:16 -0400, "Mortimer Schnerd, RN"
> wrote:

>Ed Rasimus wrote:
>> How gauche. Next you'll be putting a chrome wire through the fuel cap
>> instead of an old coat hangar. What then, a fiberglass float instead
>> of a doped cork?
>
>
>People put dope on the cork?

Migod, I found out they cover the whole airplane with it!

I was a dope user long before it became fashionable--used to build
model airplanes in my basement. Red was my favorite color, but yellow
was nice too. The two major olfactory memories of my mispent youth
were airplane dope and the distinctive odor of castor oil laced model
airplane fuel.

Ohh, and my Italian aunt's "bana calda".

Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
Smithsonian Institution Press
ISBN #1-58834-103-8

[George Z. Bush]

"Mike Marron" > wrote in message
...
> (Jim Thomas) wrote:
>
> >This led me to go find my F-15A-1, circa 1975. Level flight, 0 bank,
> >military thrust, gear & flaps down, sea level stall speed (defined as
> >30 deg AOA) was about 100 KIAS. Final approach speed under those
> >conditions was 143 KIAS. So, assuming the numbers haven't changed much
> >for the F-15C/D, staying with a 110-120 KIAS Cessna would be sporty,
> >but doable.
>
> My commercial pilot log shows that in the chaotic days following 9/11
> (29 October, 2001) while cruising along in a Cessna 210L at 160 kts.
> or so I was intercepted by an F-15 near Miami's Turkey Point nuke
> powerplant. However, since I was on an IFR flight plan and talking to
> Miami Center, they handed me off to Homestead AFB who gave me
> a heads up. "Shark XX" zipped by lickity split about 50-75 yards in
> front of me at the same altitude and perpindicular to my flightpath
> then disappeared over the Atlantic as quickly as it appeared.

I'll bet that was enough to produce a world class pucker even if you did know
for a second or towo that it was coming!!! (^-^)))

George Z.
>
>

[Mike Marron]

>"George Z. Bush" > wrote:
>>"Mike Marron" > wrote:

>>My commercial pilot log shows that in the chaotic days following 9/11
>> (29 October, 2001) while cruising along in a Cessna 210L at 160 kts.
>>or so I was intercepted by an F-15 near Miami's Turkey Point nuke
>>powerplant. However, since I was on an IFR flight plan and talking to
>>Miami Center, they handed me off to Homestead AFB who gave me
>>a heads up. "Shark XX" zipped by lickity split about 50-75 yards in
>>front of me at the same altitude and perpindicular to my flightpath
>>then disappeared over the Atlantic as quickly as it appeared.

>I'll bet that was enough to produce a world class pucker even if you did know
>for a second or towo that it was coming!!! (^-^)))

Nah. I wasn't wearing my turban that day so I actually thought it was
cool and wished I could trade in my spamcan for an Eagle. ;)

[Darrell]

"Ed Rasimus" > wrote in message
...

> Got my first (student) license supension and grounding flying a PA-22
> Colt. And passed my Private license check flight in a PA-18 Super
> Cub--damn complex, it had a radio and flaps!

And don't forget the elevator trim handle on the left you had to rotate like
mad to trim it before landing. Seems I always scratched my knuckles on the
metal wall while trying to do that. I never got my pilots license in it
because I was in the Aviation Cadet program in the Air Force. We went from
the Cub to the T-6 in Primary and then I flew the T-28 and T-33 in Basic
Training.

Strange. I never got my civilian ticket until I was Aircraft Commander in a
B-52H at Minot AFB, ND. Took the special written (civilian Regs) and got a
Commercial Multi-engine Instrument ticket. No single engine privileges
because I wasn't current in any single engine aircraft. I had to go to the
civilian airport and check out in a Mooney to get it to include single
engine. (couldn't afford to rent a multi-engine for our vacation trip).

-

B-58 Hustler History: http://members.cox.net/dschmidt1/
-

[George Shirley]

Ed Rasimus wrote:

> On Wed, 30 Jun 2004 11:18:16 -0400, "Mortimer Schnerd, RN"
> > wrote:
>
>
>>Ed Rasimus wrote:
>>
>>>How gauche. Next you'll be putting a chrome wire through the fuel cap
>>>instead of an old coat hangar. What then, a fiberglass float instead
>>>of a doped cork?
>>
>>
>>People put dope on the cork?
>
>
> Migod, I found out they cover the whole airplane with it!
>
> I was a dope user long before it became fashionable--used to build
> model airplanes in my basement. Red was my favorite color, but yellow
> was nice too. The two major olfactory memories of my mispent youth
> were airplane dope and the distinctive odor of castor oil laced model
> airplane fuel.
>
> Ohh, and my Italian aunt's "bana calda".
>
> Ed Rasimus
> Fighter Pilot (USAF-Ret)
> "When Thunder Rolled"
> Smithsonian Institution Press
> ISBN #1-58834-103-8

CAP commander when I was a kid made you rebuild the J3 if you pranged
it. Most of us rather liked doping the fabric in the hangar since you
could get high legally. We used a sort of Air Farce blue and it turned
an odd color on the cheap fabric we used. Of course in the fifties
everyone knew what kind of dope you were talking about. My grandkids
thing old granpa used the other kind on the plane.

George

[Robert Briggs]

Jim Thomas wrote:

> > Its actuallly about a C-172 getting intercepted, about a 110 knot airplane.
> > Still pretty slow though.
> > Guess we would need one of the eagle drivers to chime in...
>
> This led me to go find my F-15A-1, circa 1975. Level flight, 0 bank,
> military thrust, gear & flaps down, sea level stall speed (defined as
> 30 deg AOA) was about 100 KIAS. Final approach speed under those
> conditions was 143 KIAS. So, assuming the numbers haven't changed much
> for the F-15C/D, staying with a 110-120 KIAS Cessna would be sporty,
> but doable.

With a pair of fighters it would be fairly easy for one to pass the
Cessna at a modest pace while the other does a 360 to take over.
Another option would be to "tack", allowing a noticeably higher
airspeed.

That said, ISTM that the civvy pilot was remarkably clueless:
sufficiently so to lose his ticket, I'd have thought.

Consider this paragraph:

Wirig says the F-15 pilot, with whom he was not in
radio contact, kept lowering his landing gear and
flaps, trying to get the GA pilot to understand. "I
couldn't figure out what he was trying to get me to
do," said the 69-year-old pilot.

The military pilot "kept lowering his landing gear", eh?

I can think of two possible reasons for that: as a signal that the
Cessna's landing gear is in an abnormal state, or as a signal that Wirig
should use his gear for its intended purpose.

I can also think of two reasons to dismiss the former signal a unlikely:
if your typical 172's landing gear is in an abnormal state there is a
fair chance that its pilot will be aware of some bent metal (although
the RG *could* have a gear fault manifest in flight); and the military
pilot "kept lowering his ... flaps", making the signal either "you have
*two* visible faults on your aeroplane" or "land now". I know which *I*
reckon is more likely ...

[Alan Dicey]

>> Alan Dicey > wrote
>>The first production fly-by-wire aircraft was the F-16.

>Eunometic wrote:
>
> Concord actually. They even wanted to put sidearm controllers on it.

>Ron wrote:
>
> F-16 was the first with a DIGITAL FBW. I think Concorde, and
possibly > F-111 too had analog systems.

>Peter Stickney wrote:
>
> F-111, actually. And, perhaps the A-5 Vigilante, depending on how you
> want to define FBW.

A major problem here is that the term fly-by-wire was popularised as a
marketing soundbite by the GD team during the Lightweight Fighter
competition in the early seventies. As such it had no strict
engineering definition. Prompted by the original poster, I was using it
in the way that Harry Hillaker does: -

"'Fly-by-wire' is a totally electronic system that uses
computer-generated electrical impulses, or signals, to transmit the
pilot's commands to the flight control surfaces instead of a combination
of the push rods, bell cranks, linkages, and cables used with more
conventional hydromechanical systems."

(Harry J. Hillaker is retired vice president and deputy program director
for the F-16, General Dynamics Corporation)

- which does come down to a somewhat circular definition (fly-by-wire
is defined as what the F-16 has, so of course it is the first).
However, I think most people understand fly-by-wire to include elements
of electrical signaling and computer control, which leads us back to
Hillakers definition, which makes the defining characteristics:

* electrically signalled
* no manual connection
* pilot flies computer: computer flies plane.

I think this is also the kind of system the original poster was thinking
of, where the aircraft is kept from departing from controlled flight by
the flight control computer overriding the pilot inputs and keeping the
aircraft right on the edge of its flight envelope. My original point
was that the F-15 does not have this kind of fly-by-wire :-)

The F-16 system, manufactured by Lear Seigler, was initially an analog
system, by the way. The first digital-from-scratch FBW aircraft was the
F-18 Hornet.

If you broaden the definition of fly-by-wire to include all
electrically-signalled FCS, there are many aircraft prior to the F-16
that qualify, among them being:

The Avro Vulcan: Tim Laming's The Vulcan Story includes the aircrew
manual which describes the system as electro-hydraulic, and including
artificial feel, autostabilisation and mach trimmers.

The A-5 Vigilante:
http://www.airtoaircombat.com/background.asp?id=87&bg=305
The aircraft had a primitive fly-by-wire flight control system in which
stick movements of the stick were converted into electrical signals
which fed into actuators that controlled lateral and l longitudinal
movements. The actuators then mechanically positioned the control
valves, the horizontal stabilizer, and the spoiler activators. There was
a mechanical backup system in case this system failed.

Concorde
http://www.concordesst.com/autopilot.html
Concorde has an Automatic Flight Control System (AFCS) installed, that
for the 1970s was state of the art. The system is designed to allow
"hands off" control of the aircraft from climb out to landing. There are
2 mains parts to the system; the Autothrottles and Autopilot, and a
number of associated systems, such as the warning displays and test systems

http://www.concordesst.com/flightsys.html
Although it is described as fly-by-wire, it is not computer-controlled
and there is manual reversion. Shades of meaning, I know.

Autopilot plus autothrottle is not fly-by-wire, by the "F-16"
definitions :-)

I don't know offhand and can't find on the web a good enough description
of the F-111 FCS to tell; but I suspect that it too falls short of the
definition I am using.

Tornado is fly-by-wire, but comes after the F-16. It is also
aerodynamically stable and has a manual reversion mode.

I'm sure there are better qualified people than me on this newsgroup who
can give a more authorative opinion: I only used to work for Marconi
Avionics, so what do I know :-)

[Harry Andreas]

In article >, Alan
Dicey > wrote:

> >> Alan Dicey > wrote
> >>The first production fly-by-wire aircraft was the F-16.
>
> >Eunometic wrote:
> >
> > Concord actually. They even wanted to put sidearm controllers on it.
>
> >Ron wrote:
> >
> > F-16 was the first with a DIGITAL FBW. I think Concorde, and
> possibly > F-111 too had analog systems.
>
> >Peter Stickney wrote:
> >
> > F-111, actually. And, perhaps the A-5 Vigilante, depending on how you
> > want to define FBW.
>
> A major problem here is that the term fly-by-wire was popularised as a
> marketing soundbite by the GD team during the Lightweight Fighter
> competition in the early seventies. As such it had no strict
> engineering definition. Prompted by the original poster, I was using it
> in the way that Harry Hillaker does: -
>
> "'Fly-by-wire' is a totally electronic system that uses
> computer-generated electrical impulses, or signals, to transmit the
> pilot's commands to the flight control surfaces instead of a combination
> of the push rods, bell cranks, linkages, and cables used with more
> conventional hydromechanical systems."
>
> (Harry J. Hillaker is retired vice president and deputy program director
> for the F-16, General Dynamics Corporation)
>
> - which does come down to a somewhat circular definition (fly-by-wire
> is defined as what the F-16 has, so of course it is the first).
> However, I think most people understand fly-by-wire to include elements
> of electrical signaling and computer control, which leads us back to
> Hillakers definition, which makes the defining characteristics:
>
> * electrically signalled
> * no manual connection
> * pilot flies computer: computer flies plane.

The first two are what a fly-by-wire system is.
The third is one particular implementation of fly-by-wire.
And it doesn't matter whether it's analog or digital,
or whether the a/c is inherently unstable and the FBW
system keeps it in the air. Those are also just implementations of
fly-by-wire .
Claiming you're the first because of your particular implementation
is disingenuous.

--
Harry Andreas
Engineering raconteur

[Alan Dicey]

Harry Andreas wrote:
> In article >, Alan
> Dicey > wrote:

>>* electrically signalled
>>* no manual connection
>>* pilot flies computer: computer flies plane.
>
>
> The first two are what a fly-by-wire system is.
> The third is one particular implementation of fly-by-wire.
> And it doesn't matter whether it's analog or digital,
> or whether the a/c is inherently unstable and the FBW
> system keeps it in the air. Those are also just implementations of
> fly-by-wire .

If I understand you correctly, you hold to the view that any
electrically signalled flight control system is fly-by-wire? I think
that makes the Vulcan a pioneer, along with the Vigilante.

The point I was trying to make was that the term has only gained
currency recently, starting with the F-16. It has since been applied
retroactively to aircraft that lack the intermediate computer (be it
digital or analog), some of which have electromechanical equivalents
(mixer boxes) and/or control augmentation systems, autopilots or terrain
following systems. I don't think the term fly-by-wire was applied to
these aircraft when they were being designed or in service, but I would
be happy to be proved wrong, in the interests of illumination.

> Claiming you're the first because of your particular implementation
> is disingenuous.
>

Thats a bit harsh. I stated up front that circular reasoning was
involved in the definition I was using and also indicated that the line
wasn't clearcut. No dishonesty or insincerity involved.

And its not my claim, nor ever has been: it was GD's claim, and only in
the sense that they made a selling point out of it.

To me, fly-by-wire will always mean a system where the pilots inputs are
moderated by the flight control computers. As we have just
demonstrated, it has no clearly-agreed technical meaning, a fact which I
ascribe to its birth in the mind of a marketeer.

[Cub Driver]

On Wed, 30 Jun 2004 09:49:39 -0700, "Darrell" > wrote:

>No single engine privileges
>because I wasn't current in any single engine aircraft.

Seems to me the lesser airplane ought to be included in the greater,
just as the "lesser included offense" bit the sergeant who was found
innocent of rape, guilty of adultery.

all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

[Cub Driver]

On Wed, 30 Jun 2004 11:18:16 -0400, "Mortimer Schnerd, RN"
> wrote:

>People put dope on the cork?

Keeps them from getting gas-logged. Or water-logged. Or sumpin.

I pay no attention to the float, since you can't rely on it in flight.
After two hours, I look for a place to refuel.

all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

[Cub Driver]

On Wed, 30 Jun 2004 19:48:28 +0100, Alan Dicey
> wrote:

>I think this is also the kind of system the original poster was thinking
>of, where the aircraft is kept from departing from controlled flight by
>the flight control computer overriding the pilot inputs and keeping the
>aircraft right on the edge of its flight envelope.

And would crash without the computer? As I understand it, a human
pilot can't control the B-2 unaided. Is that correct, and would that
be a fair definition of fly-by-wire?


all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

[Harry Andreas]

In article >, Alan
Dicey > wrote:

> Harry Andreas wrote:
> > In article >, Alan
> > Dicey > wrote:
>
> >>* electrically signalled
> >>* no manual connection
> >>* pilot flies computer: computer flies plane.
> >
> >
> > The first two are what a fly-by-wire system is.
> > The third is one particular implementation of fly-by-wire.
> > And it doesn't matter whether it's analog or digital,
> > or whether the a/c is inherently unstable and the FBW
> > system keeps it in the air. Those are also just implementations of
> > fly-by-wire .
>
> If I understand you correctly, you hold to the view that any
> electrically signalled flight control system is fly-by-wire? I think
> that makes the Vulcan a pioneer, along with the Vigilante.

As long as we're talking about the primary flight controls.
I'm not familiar enough with the Vulcan to say.


> The point I was trying to make was that the term has only gained
> currency recently, starting with the F-16. It has since been applied
> retroactively to aircraft that lack the intermediate computer (be it
> digital or analog), some of which have electromechanical equivalents
> (mixer boxes) and/or control augmentation systems, autopilots or terrain
> following systems. I don't think the term fly-by-wire was applied to
> these aircraft when they were being designed or in service, but I would
> be happy to be proved wrong, in the interests of illumination.

Lots of things fall under a later definition, say, supercruise...


> > Claiming you're the first because of your particular implementation
> > is disingenuous.
> >
>
> Thats a bit harsh. I stated up front that circular reasoning was
> involved in the definition I was using and also indicated that the line
> wasn't clearcut. No dishonesty or insincerity involved.

I wasn't criticizing you....


> And its not my claim, nor ever has been: it was GD's claim, and only in
> the sense that they made a selling point out of it.

....I was commenting on GD's re-definition of the term. Sorry if that
wasn't clear.


> To me, fly-by-wire will always mean a system where the pilots inputs are
> moderated by the flight control computers. As we have just
> demonstrated, it has no clearly-agreed technical meaning, a fact which I
> ascribe to its birth in the mind of a marketeer.

Can't argue with that.
ciao.

--
Harry Andreas
Engineering raconteur

[Alan Dicey]

Harry Andreas wrote:
> In article >, Alan
> Dicey > wrote:
>>If I understand you correctly, you hold to the view that any
>>electrically signalled flight control system is fly-by-wire? I think
>>that makes the Vulcan a pioneer, along with the Vigilante.
>
>
> As long as we're talking about the primary flight controls.
> I'm not familiar enough with the Vulcan to say.
>

One reference below, look about 3/4 down the article for a paragraph
entitled Vulcan: A Revolutionary Forebear.

http://www.defensedaily.com/cgi/av/show_mag.cgi?pub=av&mon=1001&file=1001a380.htm

Anybody know if the B-52 was electrically signalled?

How about Victor or Valiant?

[Alan Dicey]

Cub Driver wrote:

> On Wed, 30 Jun 2004 19:48:28 +0100, Alan Dicey
> > wrote:
>
>>I think this is also the kind of system the original poster was thinking
>>of, where the aircraft is kept from departing from controlled flight by
>>the flight control computer overriding the pilot inputs and keeping the
>>aircraft right on the edge of its flight envelope.
>
> And would crash without the computer? As I understand it, a human
> pilot can't control the B-2 unaided. Is that correct, and would that
> be a fair definition of fly-by-wire?
>

That is my understanding of it. Some modern aircraft are designed to be
aerodynamically unstable (center of pressure in front of center of
gravity) in part or all of the flight envelope, for reasons associated
with stealth, variable geometry or vectored thrust.

Here's a couple of links with some basic descriptions of the B-2 FCS:

http://www.edwards.af.mil/articles98/docs_html/splash/jan98/cover/page_5.html

http://www.globalsecurity.org/wmd/systems/b-2-history.htm

recompose them to one line if they break in your newsreader.

Here's another discussion of flight control systems in general, with a
definition of fly-by-wire that seems to agree with mine in that it
specifies computer signal processing;

http://www.aero.polimi.it/~l050263/bacheca/Dispense_EN/06-FligCont.pdf


From what I can find, it looks as if the B-2 is designed for
fly-by-wire control, probably to keep it stealthy as much as anything.
The flying wing shape by itself does not demand FBW, as the XB-35 and
YB-49 designs of the 40's were controllable without computer assistance.

[Eunometic]

Alan Dicey > wrote in message >...
> >> Alan Dicey > wrote
> >>The first production fly-by-wire aircraft was the F-16.
>
> >Eunometic wrote:
> >
> > Concord actually. They even wanted to put sidearm controllers on it.
>
> >Ron wrote:
> >
> > F-16 was the first with a DIGITAL FBW. I think Concorde, and
> possibly > F-111 too had analog systems.
>
> >Peter Stickney wrote:
> >
> > F-111, actually. And, perhaps the A-5 Vigilante, depending on how you
> > want to define FBW.
>
> A major problem here is that the term fly-by-wire was popularised as a
> marketing soundbite by the GD team during the Lightweight Fighter
> competition in the early seventies. As such it had no strict
> engineering definition. Prompted by the original poster, I was using it
> in the way that Harry Hillaker does: -
>
> "'Fly-by-wire' is a totally electronic system that uses
> computer-generated electrical impulses, or signals, to transmit the
> pilot's commands to the flight control surfaces instead of a combination
> of the push rods, bell cranks, linkages, and cables used with more
> conventional hydromechanical systems."
>
> (Harry J. Hillaker is retired vice president and deputy program director
> for the F-16, General Dynamics Corporation)
>
> - which does come down to a somewhat circular definition (fly-by-wire
> is defined as what the F-16 has, so of course it is the first).
> However, I think most people understand fly-by-wire to include elements
> of electrical signaling and computer control, which leads us back to
> Hillakers definition, which makes the defining characteristics:
>
> * electrically signalled
> * no manual connection
> * pilot flies computer: computer flies plane.
>
> I think this is also the kind of system the original poster was thinking
> of, where the aircraft is kept from departing from controlled flight by
> the flight control computer overriding the pilot inputs and keeping the
> aircraft right on the edge of its flight envelope. My original point
> was that the F-15 does not have this kind of fly-by-wire :-)

Probably because the F15 doesn't need it. However perhaps the F15
does have some sort of 'stability augmentation system' that opperates
through the fly by wire system. Even 707 I am told had am
accelerometer in the talifin to slap the rudder to stop phugoid type
snaking.

There inherently isn't anything a digital system can do that analog
system can't except that complexity and non linear rules are much
easier to implement.

>
> The F-16 system, manufactured by Lear Seigler, was initially an analog
> system, by the way. The first digital-from-scratch FBW aircraft was the
> F-18 Hornet.
>
> If you broaden the definition of fly-by-wire to include all
> electrically-signalled FCS, there are many aircraft prior to the F-16
> that qualify, among them being:
>
> The Avro Vulcan: Tim Laming's The Vulcan Story includes the aircrew
> manual which describes the system as electro-hydraulic, and including
> artificial feel, autostabilisation and mach trimmers.
>
> The A-5 Vigilante:
> http://www.airtoaircombat.com/background.asp?id=87&bg=305
> The aircraft had a primitive fly-by-wire flight control system in which
> stick movements of the stick were converted into electrical signals
> which fed into actuators that controlled lateral and l longitudinal
> movements. The actuators then mechanically positioned the control
> valves, the horizontal stabilizer, and the spoiler activators. There was
> a mechanical backup system in case this system failed.
>
> Concorde
> http://www.concordesst.com/autopilot.html
> Concorde has an Automatic Flight Control System (AFCS) installed, that
> for the 1970s was state of the art. The system is designed to allow
> "hands off" control of the aircraft from climb out to landing. There are
> 2 mains parts to the system; the Autothrottles and Autopilot, and a
> number of associated systems, such as the warning displays and test systems


One aspect of the Concord was that its 6 elevons (ie combined
elevators and aelerons) also provided the aircraft with 'variable
camber'. The elevons are adjusted to provide the aerodynamically
optimal wing camber for the particular flight regime. This changes
the trim of the aricraft but this is compensated by pumping fuel
between for and aft tanks.

These sorts of things are much easier to do in a fly by wire system
alalog or digital.

The trim changes associated with variable wing sweep would also make
fly by wirse attractive. Furthermore the slab tail of aircaft such as
the F111 needs to provide both roll and pitch correction: again
something that must be hard to do mechanically.




>
> http://www.concordesst.com/flightsys.html
> Although it is described as fly-by-wire, it is not computer-controlled
> and there is manual reversion. Shades of meaning, I know.
>
> Autopilot plus autothrottle is not fly-by-wire, by the "F-16"
> definitions :-)
>
> I don't know offhand and can't find on the web a good enough description
> of the F-111 FCS to tell; but I suspect that it too falls short of the
> definition I am using.
>
> Tornado is fly-by-wire, but comes after the F-16. It is also
> aerodynamically stable and has a manual reversion mode.
>
> I'm sure there are better qualified people than me on this newsgroup who
> can give a more authorative opinion: I only used to work for Marconi
> Avionics, so what do I know :-)

[Dweezil Dwarftosser]

Cub Driver wrote:
>

[ much snippage...]

> As I understand it, a human
> pilot can't control the B-2 unaided. Is that correct, and would that
> be a fair definition of fly-by-wire?

I assume the B-2 would be tough to fly unaided -
but you've got a fight on your hands with almost
every gray-haired avionics guy if you insist that
FBW automatically includes a computer element.

FBW replaces mechanical links with wire; nothing more.
(Though of course, there may be a lot more attached
to a FBW system...)

[Cub Driver]

>FBW replaces mechanical links with wire;

Have to be careful how you phrase that, or the Cub will qualify!

Also the brakes on a 1936 Ford! (Has anyone else here lay beneath a
Ford on a dark night on a lonesome highway, tightening up the brake
cables because the thang didn't stop at the last stop sign?)

all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

[SteveM8597]

>From what I can find, it looks as if the B-2 is designed for
>fly-by-wire control, probably to keep it stealthy as much as anything.
>The flying wing shape by itself does not demand FBW, as the XB-35 and
>YB-49 designs of the 40's were controllable without computer assistance.
>

The B-2 has FBW controls and a 6000 psi hydraulic system to move the control
surfaces for a number of reasons, mainly stability and weight reduction. I
have several friends who have flown it and they generally describe it's flying
qualities as F-111-like. The B-35 and B-49 designs were unsuitable as bombers
because of lack of directional stability expecially on a bomb run. If you
notice, the competition (B-36) has a large vertical fin.

Steve

[Cub Driver]

>>The flying wing shape by itself does not demand FBW, as the XB-35 and
>>YB-49 designs of the 40's were controllable without computer assistance.

Not really. The 35 had those great engine pods, and the 49 had a bunch
of vertical fins, so in fact neither one was a true flying wing.
Nobody ever managed to fly the 35 enough to determine its utility (the
long shafts were the main problem), and the 49 was so afflicted by
dutch roll that the bombardier got sicksick. Plus there was the
question whether it (and a British flying wing design) wasn't prone to
spin around its lateral axis. The latter is disputed. For opposing
views see www.warbirdforum.com/cardenas.htm and
www.warbirdforum.com/tucker.htm

The Germans may have had more success with their nurflugels. It's hard
to tell; the most famous Horten design killed its test pilot in
disputed circumstances. I once corresponded with a Horten associate
who claimed that the problem with the Northrop designs had to do with
center of gravity, but I'm not enough of an engineer to follow these
arguments.


all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

[Mike Marron]

> Cub Driver > wrote:

>Plus there was the question whether it (and a British flying wing
>design) wasn't prone to spin around its lateral axis.

Having built and flown experimental flying wings since 1996 I can
attest that if you find yourself in a spin around the lateral axis
(i.e: a "tumble") better hope you have jam in your pockets cos'
your ass is toast...

http://www.motolotnie.rsi.pl/mpg/film1s.mpg

[Alan Dicey]

Cub Driver wrote:
> Not really. The 35 had those great engine pods, and the 49 had a
> bunch of vertical fins, so in fact neither one was a true flying
> wing. Nobody ever managed to fly the 35 enough to determine its
> utility (the long shafts were the main problem), and the 49 was so
> afflicted by dutch roll that the bombardier got sicksick. Plus there
> was the question whether it (and a British flying wing design)
> wasn't prone to spin around its lateral axis. The latter is disputed.
> For opposing views see www.warbirdforum.com/cardenas.htm and
> www.warbirdforum.com/tucker.htm
>

I read that the YB-35 managed to do without vertical surfaces due to the
props providing enough longtitudinal stability; although I'm not
entirely clear as to how that would work. In any case, when it came to
the YB-49 it was found that the turbines did not provide the same effect
and the vertical fins had to be added.

The British design would be the Armstrong-Whitworth AW52. Barrie Hygate
in British Experimental Jet Aircraft relates that it had severe probelms
of pitch sensitivity leading to oscillations, at least partly due to the
short control arm provided by the modestly swept back wing. One
prototype was lost in 1949 after entering divergent pitch oscillations,
the pilot making the first British use of a Martin-Baker seat for real.

All three aircraft needed at some stability augmentation system to be
safe and usable platforms. The AW52 was only ever intended as an
experimental type, to test laminar flow.

[B2431]

>From: Alan Dicey
>Date: 7/4/2004 5:27 AM Central Daylight Time
>Message-id: >
>
>Cub Driver wrote:
>> Not really. The 35 had those great engine pods, and the 49 had a
>> bunch of vertical fins, so in fact neither one was a true flying
>> wing. Nobody ever managed to fly the 35 enough to determine its
>> utility (the long shafts were the main problem),

The main reason the 35 flopped was the contraprop gearing system was unreliable
so they went with the single props which radically affected performance.

<snip>
>
>I read that the YB-35 managed to do without vertical surfaces due to the
>props providing enough longtitudinal stability; although I'm not
>entirely clear as to how that would work.

It wasn't the props as much as the drive shaft fairings.

<snip>

Dan, U.S. Air Force, retired

[Cub Driver]

>>I read that the YB-35 managed to do without vertical surfaces due to the
>>props providing enough longtitudinal stability; although I'm not
>>entirely clear as to how that would work.
>
>It wasn't the props as much as the drive shaft fairings.

Right, the fairings were long and (by the time they reached the prop)
high above the trailing edge of the wing, rather like the wing of a
paper dart. They would have acted very much like a vertical
stabilizer. (And created, as was posted, no end of problems with the
XB-35's propeller shafts, which vibrated.)

The fairings (and later the vertical fins on the YB-49) also served as
air dams, perhaps inadvertently solving a problem with swept-wing
designs, where the airstream tends to move laterally toward the
wingtips rather than straight back in the line of flight.


all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

[Mary Shafer]

On Tue, 29 Jun 2004 11:13:15 -0500, "Emilio" >
wrote:

> It is hard to believe that F-15 can fly formation with Piper Cub.
>
> http://www.pipercubforum.com/intercep.htm

I've seen thirty F/A-18s and six "Ducks" fly in formation, too. It
didn't last very long, though. Ditto the F-15 and the A-37. They
only have to be in the proper relative position long enough for the
photographer to get the photo.

> Do F-15 fly by wire system prevent the aircraft from stalling at that low
> speed? Last time I saw an aircraft with fly by wire system did such a
> stunt, Airbus plowed right in to the forest at the end of the forest!

The F-15 isn't fly-by-wire. It's augmented, but not fly-by-wire.

Mary

--
Mary Shafer Retired aerospace research engineer