Newbie questions Rail / Ejector launchers

[AL]

Hi,
> Here is a newbie question.
>
> What are the merits and the pitfalls of rail vs ejector launchers
> for guided missiles? I suppose bombs have to be ejector launched and
> rockets rail.
>
> Whenever I visit an airshow, I ended up scratching my head.


--
AL
New anti-terrorism tool, "Fly naked"
http://www.alfredivy.per.sg

[peter wezeman]

AL > wrote in message >...
> Hi,
> > Here is a newbie question.
> >
> > What are the merits and the pitfalls of rail vs ejector launchers
> > for guided missiles? I suppose bombs have to be ejector launched and
> > rockets rail.
> >
> > Whenever I visit an airshow, I ended up scratching my head.

Ejectors are used to place a missile or bomb far enough away from the
aircraft so that they are in relatively undisturbed airflow. This has been
required on every fighter that carries missiles in an internal weapons
bay, such as the F-102, F-106, YF-12, and the new FA-22. Ejectors are
also often useful for external stores to get the weapon clear of the
complex flow field near the aircraft. Extensive tests are carried out
for any new aircraft or new store to determine the separation behavior
and what type of ejector is required for it. I have a vague memory that
the F-14 required especially powerful ejectors to ensure clean separation
of bombs carried under the fuselage, as the fuselage of that aircraft is
a lifting body and stores are subjected to aerodynamic forces that tend
to push them up against the aircraft. I think it was also an F-14 that
shot itself down when the ejector for a Sparrow missile failed and the
missile lit off while still held in its recess.

Hope this helps,
Peter Wezeman
anti-social Darwinist

[Jeff Crowell]

peter wezeman wrote:
> I think it was also an F-14 that
> shot itself down when the ejector for a Sparrow missile failed and the
> missile lit off while still held in its recess.

Dunno about the above, but a Tomcat shot itself down when
a (properly functioning) Sparrow fired from one of the after
recesses pitched up while still under the aircraft, and struck the
underside of the big Grumman bird. This led to the
development of a new mark of Sparrow (AIM-7P?) which
further delayed pitchup to allow more runout.


Jeff

[Pete]

"AL" > wrote in message ...
> Hi,
> > Here is a newbie question.
> >
> > What are the merits and the pitfalls of rail vs ejector launchers
> > for guided missiles? I suppose bombs have to be ejector launched and
> > rockets rail.
> >
> > Whenever I visit an airshow, I ended up scratching my head.
>

A general rule for missiles might be:
Ejector racks next/on the fuselage
Rails away from the fuselage. underwing and wingtip.

Ejector racks kick the missile out from the fuselage to get out of the
airflow, to clear other protuberances (other missiles, etc) and also to
limit the burn effects from the missile motor.

Consider if the F-4/Sparrow were on rails. The front missile can't launch
without burning the aft missile, and the aft missile can't launch because
the front missile is in the way.
(Not counting the fact that two of the fins are recessed into the fuselage,
and the missile body itself is in a slight recess)

Pete

[Bob Martin]

> Consider if the F-4/Sparrow were on rails. The front missile can't launch
> without burning the aft missile, and the aft missile can't launch because
> the front missile is in the way.
> (Not counting the fact that two of the fins are recessed into the
fuselage,
> and the missile body itself is in a slight recess)

Originally the plan was to use rails that swing down... the front missiles
were on a trapeze system, and the aft ones were on arms that swung down from
an inboard hinge (parallel to roll axis). That got scrapped halfway through
the design process.

[WaltBJ]

F102 had rails for missiles and tubes for rockets. 3 each RX tubes
were in each of the center four doors. MX rails were pneumatically
extended and retracted. The firing cycle was thus: Doors snapped open,
rear (3) rails extended, 3 missiles fired, front rails snapped down as
rears retracted, front 3 missiles fired, front rails came up, doors
snapped closed - all in 3 seconds flat. Everybody was extremely
respectful of extended doors on the ground especially with HP
pneumatic (3000PSI) system charged. Special clamps held doors extended
when working around the Deuce in this condition.
Walt BJ

[Pete]

"WaltBJ" > wrote in message
om...
> F102 had rails for missiles and tubes for rockets. 3 each RX tubes
> were in each of the center four doors. MX rails were pneumatically
> extended and retracted. The firing cycle was thus: Doors snapped open,
> rear (3) rails extended, 3 missiles fired, front rails snapped down as
> rears retracted, front 3 missiles fired, front rails came up, doors
> snapped closed - all in 3 seconds flat. Everybody was extremely
> respectful of extended doors on the ground especially with HP
> pneumatic (3000PSI) system charged. Special clamps held doors extended
> when working around the Deuce in this condition.
> Walt BJ

Right. Rails for missiles held internally. Same as the -106.

IIRC, a guy at Loring lost part of his arm putting the downlocks on a bird
coming back from an alert mission. You had to put the locks on prior to
shutdown, and with the doors open. Fault in the system caused a door-close
just as he was putting on one of the locks.

There is no possible way to move fast enough to avoid the doors snapping
shut.

Pete

[Vygg]

peter wezeman wrote:

> AL > wrote in message >...
>
>>Hi,
>>
>>> Here is a newbie question.
>>>
>>> What are the merits and the pitfalls of rail vs ejector launchers
>>>for guided missiles? I suppose bombs have to be ejector launched and
>>>rockets rail.
>>>
>>> Whenever I visit an airshow, I ended up scratching my head.
>>>
>
> Ejectors are used to place a missile or bomb far enough away from the
> aircraft so that they are in relatively undisturbed airflow. This has been
> required on every fighter that carries missiles in an internal weapons
> bay, such as the F-102, F-106, YF-12, and the new FA-22. Ejectors are
> also often useful for external stores to get the weapon clear of the
> complex flow field near the aircraft. Extensive tests are carried out
> for any new aircraft or new store to determine the separation behavior
> and what type of ejector is required for it. I have a vague memory that
> the F-14 required especially powerful ejectors to ensure clean separation
> of bombs carried under the fuselage, as the fuselage of that aircraft is
> a lifting body and stores are subjected to aerodynamic forces that tend
> to push them up against the aircraft. I think it was also an F-14 that
> shot itself down when the ejector for a Sparrow missile failed and the
> missile lit off while still held in its recess.
>
> Hope this helps,
> Peter Wezeman
> anti-social Darwinist
>
The F-106 and F-102 used rails, not ejectors for the AIM-4. Only the AIR-2A was "ejected" from the bay.


Vygg

[AL]

Pete wrote:

>"AL" > wrote in message ...
>
>
>>Hi,
>>
>>
>>> Here is a newbie question.
>>>
>>> What are the merits and the pitfalls of rail vs ejector launchers
>>>for guided missiles? I suppose bombs have to be ejector launched and
>>>rockets rail.
>>>
>>> Whenever I visit an airshow, I ended up scratching my head.
>>>
>>>
>
>A general rule for missiles might be:
>Ejector racks next/on the fuselage
>Rails away from the fuselage. underwing and wingtip.
>
>Ejector racks kick the missile out from the fuselage to get out of the
>airflow, to clear other protuberances (other missiles, etc) and also to
>limit the burn effects from the missile motor.
>
>Consider if the F-4/Sparrow were on rails. The front missile can't launch
>without burning the aft missile, and the aft missile can't launch because
>the front missile is in the way.
>(Not counting the fact that two of the fins are recessed into the fuselage,
>and the missile body itself is in a slight recess)
>
>Pete
>
>
>
>
So a AIM-9 when mounted on the fuselage willl be ejector launched or are
they limited by design?

--
AL
New anti-terrorism tool, "Fly naked"
http://www.alfredivy.per.sg

[Bob Martin]

> So a AIM-9 when mounted on the fuselage willl be ejector launched or are
> they limited by design?

All AIM-9's are rail launched. Fuselage mounting of one would require a
short pylon and a rail attached to it.

[Pete]

"Pete" > wrote

>
> A general rule for missiles might be:
> Ejector racks next/on the fuselage
> Rails away from the fuselage. underwing and wingtip.

And of course, to any "general rule", there is an exception.

A-7
Little pylons w/ rails, mounted to the fuselage.
http://www.fas.org/man/dod-101/sys/ac/a-7-dvic154.jpg

Pete

[Pete]

"Bob Martin" > wrote in message
...
> > So a AIM-9 when mounted on the fuselage willl be ejector launched or are
> > they limited by design?
>
> All AIM-9's are rail launched. Fuselage mounting of one would require a
> short pylon and a rail attached to it.

A-7
http://www.fas.org/man/dod-101/sys/ac/a-7-dvic154.jpg

Pete

[John Keeney]

"Pete" > wrote in message
...
>
> "Bob Martin" > wrote in message
> ...
> > > So a AIM-9 when mounted on the fuselage willl be ejector launched or
are
> > > they limited by design?
> >
> > All AIM-9's are rail launched. Fuselage mounting of one would require a
> > short pylon and a rail attached to it.
>
> A-7
> http://www.fas.org/man/dod-101/sys/ac/a-7-dvic154.jpg

Looks like it fits the discription well, doesn't it.

[Alan Minyard]

On Wed, 12 Nov 2003 04:00:33 GMT, "Pete" > wrote:

>
>"Pete" > wrote
>
>>
>> A general rule for missiles might be:
>> Ejector racks next/on the fuselage
>> Rails away from the fuselage. underwing and wingtip.
>
>And of course, to any "general rule", there is an exception.
>
>A-7
>Little pylons w/ rails, mounted to the fuselage.
>http://www.fas.org/man/dod-101/sys/ac/a-7-dvic154.jpg
>
>Pete
>
As with the F-8 and F-104

Al Minyard

[Ed Rasimus]

On Wed, 12 Nov 2003 11:11:56 -0600, Alan Minyard
> wrote:

>On Wed, 12 Nov 2003 04:00:33 GMT, "Pete" > wrote:
>
>>
>>"Pete" > wrote
>>
>>>
>>> A general rule for missiles might be:
>>> Ejector racks next/on the fuselage
>>> Rails away from the fuselage. underwing and wingtip.
>>
>>And of course, to any "general rule", there is an exception.
>>
>>A-7
>>Little pylons w/ rails, mounted to the fuselage.
>>http://www.fas.org/man/dod-101/sys/ac/a-7-dvic154.jpg
>>
>>Pete
>>
> As with the F-8 and F-104
>
>Al Minyard

Certainly the F-8 mounted AIM-9s on fuselage pylons, but don't think
you'll find any Zippers with such. Strictly wing-tip mounts as I
recall.

I don't think there's a "general rule" for rail vs ejector. Certainly
free-fall weapons are ejector released, predominantly to insure clear
and immediate separation from the airframe.

Missiles, it seems, depend upon the size. Smaller missiles tend toward
rail mount since they obtain an initial stabilized vector from their
launch run. Larger missiles, with a larger impulse motor, seem to lean
toward ejector release with an umbilical that allows for motor fire
once clear of the airframe. Examples would be the large AGM-12C
Bullpup (ejector) compared to the AGM-12B (rail). Or, the AGM-45
Shrike (rail) compared to the AGM-78 Standard (ejector).

[peter wezeman]

Vygg > wrote in message >...
> peter wezeman wrote:
>
> > AL > wrote in message >...
> >
> >>Hi,
> >>
> >>> Here is a newbie question.
> >>>
> >>> What are the merits and the pitfalls of rail vs ejector launchers
> >>>for guided missiles? I suppose bombs have to be ejector launched and
> >>>rockets rail.
> >>>
> >>> Whenever I visit an airshow, I ended up scratching my head.
> >>>
> >
> > Ejectors are used to place a missile or bomb far enough away from the
> > aircraft so that they are in relatively undisturbed airflow. This has been
> > required on every fighter that carries missiles in an internal weapons
> > bay, such as the F-102, F-106, YF-12, and the new FA-22. Ejectors are
> > also often useful for external stores to get the weapon clear of the
> > complex flow field near the aircraft. Extensive tests are carried out
> > for any new aircraft or new store to determine the separation behavior
> > and what type of ejector is required for it. I have a vague memory that
> > the F-14 required especially powerful ejectors to ensure clean separation
> > of bombs carried under the fuselage, as the fuselage of that aircraft is
> > a lifting body and stores are subjected to aerodynamic forces that tend
> > to push them up against the aircraft. I think it was also an F-14 that
> > shot itself down when the ejector for a Sparrow missile failed and the
> > missile lit off while still held in its recess.
> >
> > Hope this helps,
> > Peter Wezeman
> > anti-social Darwinist
> >
> The F-106 and F-102 used rails, not ejectors for the AIM-4. Only the AIR-2A was "ejected" from the bay.
>
>
> Vygg

In the pictures I have seen, the Falcon missiles on the F-102 and F-106
were held on parallelogram linkage devices that swung them down out of
the weapons bay. I had thought that this was a type of ejector, but is
it actually considered to be a retractable rail mount? Did it release
the missile with a downward component of velocity, or did the missile
fly itself forward off the rail? Did the missile guidance system have
to establish lock on the target before it was launched?

thank you
Peter Wezeman
anti-social Darwinist

[Vygg]

peter wezeman wrote:

> Vygg > wrote in message
> >...
>
>> peter wezeman wrote:
>>
>>
>>> AL > wrote in message
>>> >...
>>>
>>>
>>>> Hi,
>>>>
>>>>
>>>>> Here is a newbie question.
>>>>>
>>>>> What are the merits and the pitfalls of rail vs ejector
>>>>> launchers for guided missiles? I suppose bombs have to be
>>>>> ejector launched and rockets rail.
>>>>>
>>>>> Whenever I visit an airshow, I ended up scratching my head.
>>>>>
>>>>>
>>> Ejectors are used to place a missile or bomb far enough away
>>> from the aircraft so that they are in relatively undisturbed
>>> airflow. This has been required on every fighter that carries
>>> missiles in an internal weapons bay, such as the F-102, F-106,
>>> YF-12, and the new FA-22. Ejectors are also often useful for
>>> external stores to get the weapon clear of the complex flow
>>> field near the aircraft. Extensive tests are carried out for
>>> any new aircraft or new store to determine the separation
>>> behavior and what type of ejector is required for it. I have a
>>> vague memory that the F-14 required especially powerful
>>> ejectors to ensure clean separation of bombs carried under the
>>> fuselage, as the fuselage of that aircraft is a lifting body
>>> and stores are subjected to aerodynamic forces that tend to
>>> push them up against the aircraft. I think it was also an F-14
>>> that shot itself down when the ejector for a Sparrow missile
>>> failed and the missile lit off while still held in its recess.
>>>
>>> Hope this helps, Peter Wezeman anti-social Darwinist
>>>
>>>
>> The F-106 and F-102 used rails, not ejectors for the AIM-4. Only
>> the AIR-2A was "ejected" from the bay.
>>
>>
>> Vygg
>>
>
> In the pictures I have seen, the Falcon missiles on the F-102 and
> F-106 were held on parallelogram linkage devices that swung them
> down out of the weapons bay. I had thought that this was a type of
> ejector, but is it actually considered to be a retractable rail
> mount? Did it release the missile with a downward component of
> velocity, or did the missile fly itself forward off the rail? Did
> the missile guidance system have to establish lock on the target
> before it was launched?
>
> thank you Peter Wezeman anti-social Darwinist
>
On the F-106, rails 1 & 2 (forward) were connected by a web (actually a
large metal plate rather than a spiderweb contraption), and rails 3 & 4
(aft) separately bracketed the ejector rack for the AIR-2A. The forward
rails came down together (obviously, since they were connected) and the
aft rails lowered simultaneously after 1 & 2 were retracted and clear.
The Falcons were fired in pairs after the aircraft locked onto the
target (MA-1A Radar for the AIM-4F, IR sensor on the upper part of the
nose forward of the windscreen for the AIM-4G). The missiles came
forward off of the rails. No ejector cartridges were loaded (or
necessary) for the Falcons.

The AIR-2A was kicked down out of the bay by a pair of ejectors and a
lanyard pulled a pin in the rocket motor to fire it once the weapon
cleared the aircraft. No actual "lock-on" was necessary for the Genie as
it was ballistic. The AWCIS did, however, compute a flight path and
time-to-go for detonation, as well as an egress sequence for the
aircraft to escape the blast. That path was flown automatically if the
pilot was in Auto AFCS and had SAGE Datalink in control.

Can't speak for the Dagger as the only ones that I ever were around were
all QFs. The drones didn't use the weapons bay, AFAIK.

Vygg

[José Herculano]

> Certainly the F-8 mounted AIM-9s on fuselage pylons, but don't think
> you'll find any Zippers with such. Strictly wing-tip mounts as I
> recall.

The Zipper can carry them on the wing-tips, as you stated, but also on a
double belly pylon, just in front of the main gear doors.

_____________
José Herculano

[WaltBJ]

The F104G had a double rail pylon (2xAIM9s) that could be mounted on
the center fuselage station. I don't know if the C had the same
capability. FWIW USAF experimented with a 104A carrying a Genie (MB1)
nuke rocket on an extendable rail hung on a center fuselage station. I
think the problem was lack of precise ranging information for an
accurate launch. (Glad they didn't do it - nukes were always a PITA.)
Walt BJ

[Alan Minyard]

On Wed, 12 Nov 2003 17:47:36 GMT, Ed Rasimus > wrote:

>On Wed, 12 Nov 2003 11:11:56 -0600, Alan Minyard
> wrote:
>
>>On Wed, 12 Nov 2003 04:00:33 GMT, "Pete" > wrote:
>>
>>>
>>>"Pete" > wrote
>>>
>>>>
>>>> A general rule for missiles might be:
>>>> Ejector racks next/on the fuselage
>>>> Rails away from the fuselage. underwing and wingtip.
>>>
>>>And of course, to any "general rule", there is an exception.
>>>
>>>A-7
>>>Little pylons w/ rails, mounted to the fuselage.
>>>http://www.fas.org/man/dod-101/sys/ac/a-7-dvic154.jpg
>>>
>>>Pete
>>>
>> As with the F-8 and F-104
>>
>>Al Minyard
>
>Certainly the F-8 mounted AIM-9s on fuselage pylons, but don't think
>you'll find any Zippers with such. Strictly wing-tip mounts as I
>recall.
>
>I don't think there's a "general rule" for rail vs ejector. Certainly
>free-fall weapons are ejector released, predominantly to insure clear
>and immediate separation from the airframe.
>
>Missiles, it seems, depend upon the size. Smaller missiles tend toward
>rail mount since they obtain an initial stabilized vector from their
>launch run. Larger missiles, with a larger impulse motor, seem to lean
>toward ejector release with an umbilical that allows for motor fire
>once clear of the airframe. Examples would be the large AGM-12C
>Bullpup (ejector) compared to the AGM-12B (rail). Or, the AGM-45
>Shrike (rail) compared to the AGM-78 Standard (ejector).
>
There was a seldom used set of rails that mounted on the C/L just aft
or the front gear door. I don't think they were used operationally, but
they did exist.

Al Minyard