"PENTAGON WORKING TO GIVE F-35 JSF NUCLEAR-STRIKE CAPABILITY"

On May 11, 11:30 am, "Keith Willshaw"
wrote:
"Ken S. Tucker" wrote in ...



On May 10, 8:37 pm, Bill Shatzer wrote:
Ken S. Tucker wrote:
On May 10, 4:24 pm, "Keith Willshaw"
wrote:

"Ken S. Tucker" wrote in
...

On May 10, 12:23 pm, "Keith Willshaw"

Name one missile that does so and the mechanism it uses for braking.

Sputnik, returned dogs safely in the 50's. They used
speed brakes, then parachutes.

No it didnt, Sputnik was not recoverable and the dog Laika died in
space
And the other 24 dog missions ?
Please aquaint and get back to us.
Ken
[...]

Dunno, but the first Soviet canine passengers successfully returned from
orbit weren't in the 1950s.

The discussion involves sub-orbital, (IRBM's or MRBM's),
http://en.wikipedia.org/wiki/Soviet_space_dogs
to prove sub-orbital re-entry capability, see it in 1951.
(Keith went off track with Laika).
Ken

Actually the person who raised the issue of dogs in Sputnik
was you. Laika was the ONLY dog to fly in a sputnik
in the 1950's.
Keith

I'm sorry Keith, the ref disagrees with you.
But I'll agree node my head.
Good Bye.
Ken

Ken S. Tucker wrote:
[snip]

For instance using ADC (Analog to Digital) and DAC
(Digital to Analog) converters going into an Elektronic
Brain....was nearly sci-fi.

It still is sci-fi.

Although nowdays it is the analog side they do not know about.

Andrew Swallow

On May 12, 5:13*pm, Andrew Swallow wrote:
Ken S. Tucker wrote:

[snip]

For instance using ADC (Analog to Digital) and DAC
(Digital to Analog) converters going into an Elektronic
Brain....was nearly sci-fi.

It still is sci-fi.

Although nowdays it is the analog side they do not know about.

Andrew Swallow

Not really. We were collecting analog data as late as early 90s. Some
were doing digital , most data was analog. Had to do conversions, did
that on tape systems, read analog tape, created digital tape, ran
digital tape as input to computer systems. I don't know if they do
digital data recordings directly, now, would make sense but there are
reasons not to do it. you can get higher frequency of data with analog
data. highest was FM, could get 1000 samples / sec. Real interesting
looking at realtime data. Usually wouldn't print it until right at
where you needed data. Recorders spit out tons of thermal paper. Fun
to watch. Vast majority was 20 samples / sec at most, which was fine
for analog. I had some data requirements at 10000 cycles / sec, what
they did was run it at 10th of the speed it was recorded at. For some
reason, analog to digital was a 1:1 time write to tape. One hour of
data took one hour to convert to digital record. Then we had to run
the digital tape through some other programs to make sense of it all.
Usually was just a voltage point. Conversion created say acft, tail,
flight #, date, time, mach #, alt and whatnot. Lots of the conversion
literally was a patch board hookup. Flight data reels in raw format
were probably an inch, inch and a half wide, weighed about 50 lbs. One
wasn't bad, two were real strain to carry. Most fighters had one tape
recorder. Easier to do analog data right off of transducers.

On May 13, 1:03 am, frank wrote:
On May 12, 5:13 pm, Andrew Swallow wrote:

Ken S. Tucker wrote:

[snip]

For instance using ADC (Analog to Digital) and DAC
(Digital to Analog) converters going into an Elektronic
Brain....was nearly sci-fi.

It still is sci-fi.

Although nowdays it is the analog side they do not know about.

Andrew Swallow

Not really. We were collecting analog data as late as early 90s. Some
were doing digital , most data was analog. Had to do conversions, did
that on tape systems, read analog tape, created digital tape, ran
digital tape as input to computer systems. I don't know if they do
digital data recordings directly, now, would make sense but there are
reasons not to do it. you can get higher frequency of data with analog
data. highest was FM, could get 1000 samples / sec. Real interesting
looking at realtime data. Usually wouldn't print it until right at
where you needed data. Recorders spit out tons of thermal paper. Fun
to watch. Vast majority was 20 samples / sec at most, which was fine
for analog. I had some data requirements at 10000 cycles / sec, what
they did was run it at 10th of the speed it was recorded at. For some
reason, analog to digital was a 1:1 time write to tape. One hour of
data took one hour to convert to digital record. Then we had to run
the digital tape through some other programs to make sense of it all.
Usually was just a voltage point. Conversion created say acft, tail,
flight #, date, time, mach #, alt and whatnot. Lots of the conversion
literally was a patch board hookup. Flight data reels in raw format
were probably an inch, inch and a half wide, weighed about 50 lbs. One
wasn't bad, two were real strain to carry. Most fighters had one tape
recorder. Easier to do analog data right off of transducers.

Let me guess, corrections invited.
Today, software and computer enhanced flying is
well known to a military pilot. (The rumor that the
F-22's crossing the International dateline caused
the computer - via software glitch - to crash is a
typical example).
In a sense, software removes pilots burden.
When was software first used? I'm guessing it was
1st used to automatically control the F-111 wing
sweep.
Ken

In article
,
"Ken S. Tucker" wrote:

On May 13, 1:03 am, frank wrote:
On May 12, 5:13 pm, Andrew Swallow wrote:

Let me guess, corrections invited.
Today, software and computer enhanced flying is
well known to a military pilot. (The rumor that the
F-22's crossing the International dateline caused
the computer - via software glitch - to crash is a
typical example).
In a sense, software removes pilots burden.
When was software first used? I'm guessing it was
1st used to automatically control the F-111 wing
sweep.
Ken

Ken,

The pilot commanded the F-111 wing sweep position via a lever that was
mounted underneath the left canopy rail. It hung underneath the rail
and was hinged to flip up (outboard) to stay out of the way. The pilot
would move his left hand from the throttles up to the handle, grab it
and rotate it down, then push it forward or pull it back. Forward
equals wings move forward, back equals wings move back. When the handle
was stowed in the outboard spring loaded position, it was friction
locked from moving forward or back. The wing sweep control handle was
connected via manual cable (not electrical cable) to the high-lift
control system, which in turn controlled the wing sweep position. Wing
sweep position was directly proportional to wing sweep handle position.
The two hydraulic systems provided control power to move the wings. The
wing sweep actuator was a non-reversible system that prevented the wing
sweep position from being affected by airloads. The forward position
was 16 degrees leading edge sweep. The aft position was 72.5 degrees
leading edge sweep. The wings moved at 3.8 degrees per second. The
aircraft placard G limits were -3.0 to +7.33 symmetric when the wings
were stationary. This were later changed to -1.5 to +7.33. During wing
sweep, the placard G limits were 0 to +4.0 symmetrical. Assymmetric G
during wing sweep was prohibited.

The F-14 Tomcat used a more sophisticated wing sweep system. The
pilot's right throttle contained a five position thumb switch (button)
on the inboard side which was very similar to the trim button on the
stick except that unlike the trim button which was spring loaded to the
center position, the pilot could place the wing sweep button in any of
the five positions. The positions we

Forward: Sweep wings forward
Aft: Sweep wings aft
Down: Sweep wings to sixty degrees (I think)
Up: Autosweep
Center: No command

In the Autosweep mode, the Central Air Data Computer (an analog device)
commanded the wing sweep position according to Mach number, using a
pressure altitude bias. Furthermore, regardless of wing sweep mode, the
CADC would not allow the wings to be over-sped. If the pilot manually
commanded the wings forward, the CADC would stop the wing sweep movement
when they reached the computed Maximum Safe Mach value. If the pilot
left the wing sweep control in the center (no command) at takeoff
instead of up (Auto) then the CADC would start to sweep the wings aft
during aircraft acceleration to prevent overspeeding the them. The
forward position was 20 degrees leading edge sweep. The aft position
was 68 degrees leading edge sweep. The wings moved at 15 degrees per
second. The aircraft placard G limits were -1.5 to +6.5 symmetric even
during wing sweep. Grumman improved on the F-111's wing box to gain
this capability, unfortunately at the expense of a substantial amount of
extra weight. Variable geometry wings proved to be a great asset to the
F-111 in the interdiction/strike role. In my opinion it provided no
benefit to the F-14 in the A/A role. The F-15A empty weight was 28,500
pounds. The F-14A empty weight was 40,000 pounds. Most of this was due
to the VG component of the aircraft. These two aircraft are nearly the
same length.

The F-14 used a simple fly-by-wire throttle. The interconnect between
the throttles and the engine fuel controls was electrical. The F-16
uses a similar FBW throttle system, that compliments its FBW flight
control system which which GD borrowed from the F-111. GD used the
Vark's triple channel FBW flight control system, added a fourth channel,
and added a few more features (ie. limiters, some of which were
eventually added to the Vark's FBW FCS) and then used it in the F-16.

--


Kurt Todoroff

Markets, not mandates and mob rule.
Consent, not coercion.

Kurt R. Todoroff wrote:
Variable geometry wings proved to be a great asset to the
F-111 in the interdiction/strike role. In my opinion it provided no
benefit to the F-14 in the A/A role. The F-15A empty weight was 28,500
pounds. The F-14A empty weight was 40,000 pounds.

A couple of comments: VG helped the Tomcat in the A/A role by
extending loiter time, and in the Fleet Air Defense role they spent
a lot of time at max conserve. And, once the F-14 got decent engines
it was a pretty good dogfighter, some of that because the wing
optimized as you went along. One disadvantage was that, if your
opponent knew what he was doing he could look at you and deduce your
energy state from your wing position. Whether he was able to do
anything about depended on what he flew--for example, the MiG-23,
also VG, could not sweep his wings at more than 2.5G, so if you kept
the pressure on he was pretty well stuck in a non-optimal configuration
regardless.



Jeff

--
Love stinks.
J. Geils

In article ,
Jeff Crowell wrote:

Kurt R. Todoroff wrote:
Variable geometry wings proved to be a great asset to the
F-111 in the interdiction/strike role. In my opinion it provided no
benefit to the F-14 in the A/A role. The F-15A empty weight was 28,500
pounds. The F-14A empty weight was 40,000 pounds.

A couple of comments: VG helped the Tomcat in the A/A role by
extending loiter time, and in the Fleet Air Defense role they spent
a lot of time at max conserve. And, once the F-14 got decent engines
it was a pretty good dogfighter, some of that because the wing
optimized as you went along. One disadvantage was that, if your
opponent knew what he was doing he could look at you and deduce your
energy state from your wing position. Whether he was able to do
anything about depended on what he flew--for example, the MiG-23,
also VG, could not sweep his wings at more than 2.5G, so if you kept
the pressure on he was pretty well stuck in a non-optimal configuration
regardless.



Jeff

Hi Jeff,

Crediting VG with extending the Tomcat's loiter time is using circular
reasoning. You don't increase loiter performance by making the aircraft
heavier. A simpler, less costly, method would have been to use a fixed
wing and then regain those eleven thousand pounds and reduce the wing
loading, thus reducing the associated induced drag and the loiter fuel
requirements. The drawback would have been reduced supersonic range
which, prior to the F-22, was overrated by the USAF and USN.

I'm not convinced that the VG wing contributed to the Tomcat's close in
fighting capability over a fixed wing. I would argue the opposite. The
CADC scheduled the wing position according to Mach number, not how hard
the pilot was pulling on the pole, and not according to G loading. The
C_L versus AOA curve on all VG aircraft becomes flatter with
progressively greater wing sweep angle. For pure maneuverability and/or
loiter, the unswept wing provides the greatest benefit of high C_L and
low induced drag. For pure speed, the highly swept wing is the choice.
I would be curious to know how the F-15 carrying six AIM-54s would fare
in the Tomcat's loiter environment. I would like to hear John Carrier's
take on this.

You are correct about the engines. The Tomcat (and the Vark) both
suffered from poor P_s due to their underpowered TF-30 engines. I read
in AW&ST a version of the test report on the flight test program of the
F-14 with the GE F110-GE-400 engines. The Tomcat realized very
significant performance increases in all flight regimes with the GE
engines. The most notable improvements were in engine reliability
during hostile flight environments. During the flight testing, the crew
took the F-14 to FL600, slowed to approach speed, and then cycled one
engine throttle back and forth between Idle and Max AB. Except for one
minor self-correcting hickup, the engines responded and performed
superbly in this environment. Afterburner lightoff and termination were
flawless.

--


Kurt Todoroff

Markets, not mandates and mob rule.
Consent, not coercion.

"Ken S. Tucker" wrote in message
...

In a sense, software removes pilots burden.
When was software first used? I'm guessing it was
1st used to automatically control the F-111 wing
sweep.
Ken

AFAIK the first aircraft to use a digital flight control system was
a modified F-8C with the F-16 being the first aircraft fitted
with the system on the production line.

Keith

On May 13, 12:27*pm, "Keith Willshaw"
wrote:
"Ken S. Tucker" wrote in ...

In a sense, software removes pilots burden.
When was software first used? I'm guessing it was
1st used to automatically control the F-111 wing
sweep.
Ken

AFAIK the first aircraft to use a digital flight control system was
a modified F-8C with the F-16 being the first aircraft fitted
with the system on the production line.

Keith

Yep, that was the original NASA prototype. Fun fact, related to how I
originally came across it: the control unit for the computer system
used in the first phase of testing was a surplus Apollo DSKY unit.
Imagine trying to punch in "nouns" and "verbs" at Mach 2, backed up by
a few KB of ferrite-core memory...

-JTD

Kurt R. Todoroff wrote:
Variable geometry wings proved to be a great asset to the
F-111 in the interdiction/strike role. In my opinion it provided no
benefit to the F-14 in the A/A role. The F-15A empty weight was 28,500
pounds. The F-14A empty weight was 40,000 pounds.

Jeff Crowell wrote:
A couple of comments: VG helped the Tomcat in the A/A role by
extending loiter time, and in the Fleet Air Defense role they spent
a lot of time at max conserve. And, once the F-14 got decent engines
it was a pretty good dogfighter, some of that because the wing
optimized as you went along. One disadvantage was that, if your
opponent knew what he was doing he could look at you and deduce your
energy state from your wing position. Whether he was able to do
anything about depended on what he flew--for example, the MiG-23,
also VG, could not sweep his wings at more than 2.5G, so if you kept
the pressure on he was pretty well stuck in a non-optimal configuration
regardless.

Kurt R. Todoroff wrote:
Crediting VG with extending the Tomcat's loiter time is using circular
reasoning. You don't increase loiter performance by making the aircraft
heavier. A simpler, less costly, method would have been to use a fixed
wing and then regain those eleven thousand pounds and reduce the wing
loading, thus reducing the associated induced drag and the loiter fuel
requirements. The drawback would have been reduced supersonic range
which, prior to the F-22, was overrated by the USAF and USN.

You make an excellent point--I wonder what the Turkey's approach
speed would have been with fixed geometry wings which would have
also permitted the sprint speed. I completely agree with your
comments regarding the overemphasis on sprint speed, at least as
regards the top end Mach number of that sprint BUT... Part of the
stated need for the sprint speed was for a late-launching (or out of
position) interceptor to get into position to kill the archer
instead of shooting at arrows. The Backfire and Blackjack were
seen as pretty fearsome opponents. ISTR that the Phantom came
aboard at about 135 knots, there was value seen in reducing that
number with the F-14; again, a lighter aircraft would have done that,
all else equal.

The swing mechanism was a reliability risk, too, though I don't know
how that compared to other maintenance items on the bird.


I'm not convinced that the VG wing contributed to the Tomcat's close in
fighting capability over a fixed wing. I would argue the opposite. The
CADC scheduled the wing position according to Mach number, not how hard
the pilot was pulling on the pole, and not according to G loading. The
C_L versus AOA curve on all VG aircraft becomes flatter with
progressively greater wing sweep angle. For pure maneuverability and/or
loiter, the unswept wing provides the greatest benefit of high C_L and
low induced drag. For pure speed, the highly swept wing is the choice.

Well, probably the correct argument to have is how badly do you need
the turning performance of the unswept configuration in a modern (even
modern as-of then) fight. ROE and training to fight the previous war
versus Speed Is Life!


I would be curious to know how the F-15 carrying six AIM-54s would fare
in the Tomcat's loiter environment. I would like to hear John Carrier's
take on this.

Someone with access to an Eagle Dash 1 could probably dope out a similar
drag index and make a stab at it.


You are correct about the engines. The Tomcat (and the Vark) both
suffered from poor P_s due to their underpowered TF-30 engines. I read
in AW&ST a version of the test report on the flight test program of the
F-14 with the GE F110-GE-400 engines. The Tomcat realized very
significant performance increases in all flight regimes with the GE
engines. The most notable improvements were in engine reliability
during hostile flight environments. During the flight testing, the crew
took the F-14 to FL600, slowed to approach speed, and then cycled one
engine throttle back and forth between Idle and Max AB. Except for one
minor self-correcting hickup, the engines responded and performed
superbly in this environment. Afterburner lightoff and termination were
flawless.

Pretty bloody impressive!


Jeff

--
Murphy's Laws of the gunfight:
Always assume there is one more, somewhere.