Stealthy air to air missile?

With a stealthy fighter you could make an attack on another aircraft
without alerting them, except for the IR signature of the missile's
rocket or ramjet engine.

Is anybody planning a stealth AAM that uses a turbojet?

-HJC

"Henry J Cobb" wrote...
With a stealthy fighter you could make an attack on another aircraft
without alerting them, except for the IR signature of the missile's
rocket or ramjet engine.

Is anybody planning a stealth AAM that uses a turbojet?

Given its speed and short time of flight, an IR AAM is already stealthy except
for the exhaust plume. A smokeless exhaust would help "complete" the stealth.
OTOH, if the exhaust plume is your first and only indicator of the missile
launch, you may well be too late for evasion...

A turbojet engine would make the missile slower, bigger, heavier, and less
maneuverable.

"John R Weiss" wrote in message
news:NT07c.50316$SR1.90094@attbi_s04...
"Henry J Cobb" wrote...
With a stealthy fighter you could make an attack on another aircraft
without alerting them, except for the IR signature of the missile's
rocket or ramjet engine.

Is anybody planning a stealth AAM that uses a turbojet?

Given its speed and short time of flight, an IR AAM is already stealthy
except
for the exhaust plume.

That and the heat emitted by the rocket motor which can trip
a sensor.

A smokeless exhaust would help "complete" the stealth.
OTOH, if the exhaust plume is your first and only indicator of the missile
launch, you may well be too late for evasion...

A turbojet engine would make the missile slower, bigger, heavier, and less
maneuverable.


A ramjet on the other hand could give better range and be less visible
in IR which may well be why the Meteor AAM is being designed round
one. Note though that Meteor has an active radar guidance system.

Keith

In article ,
Henry J Cobb writes:
With a stealthy fighter you could make an attack on another aircraft
without alerting them, except for the IR signature of the missile's
rocket or ramjet engine.

Humph! Most small AAMs have a diameter of 5" (12.7 cm). and the
bigger ones have a diameter of between 8' (20.3cm) and 12" (30.5 cm).
Without any sort of stealthing, you're talking about a mighty small
target for any sort of sensor, from radar to the Mk I Eyeball.
Tiy get more of a return from the exhaust plume of the rocket motor,
and from the plume of the pyrotechnic Gas Generator used to power teh
hydraulics & such.
The IR signature starts out by being dominated by hte engine exhaust,
but by the tiem the motor burns out, and the coast phace begins, the
host parts are the nose and leading edges. No way to get around that.

I don't think stealthy missile airframes are high on anybody's
priority list.

Passive sensors, such as IR homers, are the best bet to keep a missile
undetected.

Is anybody planning a stealth AAM that uses a turbojet?

Nobody rational. You don't get the thrust you nees at high mach
numbers for a missile from a turbojet.

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

"Keith Willshaw" wrote...

A ramjet on the other hand could give better range and be less visible
in IR which may well be why the Meteor AAM is being designed round
one. Note though that Meteor has an active radar guidance system.

One problem with ramjets in the past has been the high initial velocity
(supersonic, or near so) required for ignition. Has any progress been made in
low-speed ignition?

IIRC, the V-2 had a "pulse ramjet" engine, which gave it the characteristic
sound and its "buzz bomb" moniker. I don't know if that would be suitable for
AAM use.

"John R Weiss" wrote in message
news:fb37c.49557$_w.810363@attbi_s53...
"Keith Willshaw" wrote...

A ramjet on the other hand could give better range and be less visible
in IR which may well be why the Meteor AAM is being designed round
one. Note though that Meteor has an active radar guidance system.

One problem with ramjets in the past has been the high initial velocity
(supersonic, or near so) required for ignition. Has any progress been
made in
low-speed ignition?


Apparently so

IIRC, the V-2 had a "pulse ramjet" engine, which gave it the
characteristic
sound and its "buzz bomb" moniker. I don't know if that would be suitable
for
AAM use.


The pulse jet isn't really a ramjet , it can run at zero airspeed
though not at full power and isnt terribly efficient ut it is
simple and cheap. It might make suitable power plant for a
cheap cruise missile, which is what the V1 was but not an AAM

Keith

Henry J Cobb wrote in :

With a stealthy fighter you could make an attack on another aircraft
without alerting them, except for the IR signature of the missile's
rocket or ramjet engine.

Is anybody planning a stealth AAM that uses a turbojet?

-HJC


Rocket motors also have a UV signature.Some missile warning systems use
both bands to reduce false warnings.

--
Jim Yanik
jyanik-at-kua.net

"Keith Willshaw" wrote in message ...
"John R Weiss" wrote in message
news:NT07c.50316$SR1.90094@attbi_s04...
"Henry J Cobb" wrote...
With a stealthy fighter you could make an attack on another aircraft
without alerting them, except for the IR signature of the missile's
rocket or ramjet engine.

Is anybody planning a stealth AAM that uses a turbojet?

Given its speed and short time of flight, an IR AAM is already stealthy
except
for the exhaust plume.

That and the heat emitted by the rocket motor which can trip
a sensor.

A smokeless exhaust would help "complete" the stealth.
OTOH, if the exhaust plume is your first and only indicator of the missile
launch, you may well be too late for evasion...

A turbojet engine would make the missile slower, bigger, heavier, and less
maneuverable.

A ramjet on the other hand could give better range and be less visible
in IR which may well be why the Meteor AAM is being designed round
one. Note though that Meteor has an active radar guidance system.

I think that the use of a ramjet is primarily to do with range;
rockets need to carry both fuel and oxidant, ramjets only need fuel
(the oxidant is in the air) so for the same size/weight, can have a
much longer range.

I think that the principal warning of missile attack that jets get is
when they are 'painted' by the enemy fighter's radar. Of course, they
would also detect the radar emissions of an incoming active-radar AAM.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk
Discussion forum at: http://forums.delphiforums.com/autogun/messages/

"Peter Stickney" wrote in message
...
the
host parts are the nose and leading edges. No way to get around that.

Hippag. It goes some way to helping that by cryogenically cooling the seeker
head before launch. (Though mainly to improve efficiecy of the IR sensor
than to reduce heat signature.)

Si

In article ,
"Simon Robbins" writes:
"Peter Stickney" wrote in message
...
the
host parts are the nose and leading edges. No way to get around that.

Hippag. It goes some way to helping that by cryogenically cooling the seeker
head before launch. (Though mainly to improve efficiecy of the IR sensor
than to reduce heat signature.)

That cools the seeker cell itself, not the nosecone/radome/IRdome.
The outer surfaces of teh missile structure are not cooled.
The plume of teh motor & gas generator has a not insignificant radar
signature as well, for most propellant formulations used today. In
order to increase the Specific Impulse (Thrust/Mass/Time), most solid
propellant grains, and some liquid propellants that have been tried,
use Aluminum or Magnesium powder in teh mixture. The unburned
Aluminum dust makes a detectable signature. North Vietnamese Fan Song
Radar Operators were able to detect ARM launches from the various SAM
Supressors flying against them, and occasionally shut down in time.

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