Convair Lenticular Missile

[KJ_Lesnick]

The B-70 was to use a 500-pound lenticular missile using three AIM-4 Falcon motors and a pair of thrust vectoring paddles along the tips of the wings as a defense against enemy attack.  My question is, assuming it's not classified -- why was it cancelled?

[Mr.Creak]

It was cancelled because the B-70 was.
There's no need for a defensive missile for a bomber that's not going to enter service.
http://en.wikipedia.org/wiki/Pye_Wacket
http://www.designation-systems.net/dusrm/app4/pyewacket.html

[KJ_Lesnick]

How would it have compared to other missiles of the day in terms of overall agility and acceleration, accuracy, ability to keep up with a rapidly maneuvering fighter?

[Mr.Creak]

From the links:

This shape showed high supersonic stability and lift even at extreme angles of attack, and its evenly distributed mass made the needed super-agility possible.

and

The specifications for the proposed DAMS called for an air-launched defensive missile, capable of engaging incoming missiles at relative speeds of up to Mach 7,[2] surviving a rate of acceleration between 60 g to 250 g, and being able to undertake rapid terminal-phase guidance changes in any direction.[7]

Following initial studies and wind-tunnel testing at the Air Proving Ground Center and Arnold Engineering Development Center,[2] a radically unconventional design emerged that featured a lenticular, wedge-shaped airframe.[2] The lenticular design was considered to have the best handling characteristics at extremely high angles of attack, and would theoretically possess ideal mass distribution, giving the missile outstanding terminal agility.[2] In addition, the lenticular design allowed for omnidirectional launching from the carrying aircraft.

This is discussing shooting down incoming SA-2 SAMs!
With a top speed of Mach 6.5 it sounds pretty damn' fast...

[rickshaw]

How much of that speed was momentum from the launching aircraft?  B-70s cruised at over Mach 2..

[Mr.Creak]

How much of that speed was momentum from the launching aircraft?

Good question.
All I can think of is that the speed is given as a single figure while, at the same time, the missile was said to be capable of "omnidirectional launching from the carrying aircraft".
If any of the speed were attributable to the launch velocity then I'd expect any missile fired rearwards to be ~Mach 2 less than than any fired forwards...

[rickshaw]

If it could cancel momentum quickly enough perhaps.  Simple conservation of momentum would have it that it would become -M2 eventually but not instantaneously.  While I understand the launcher consisted of a stack of Pyewackets which were dropped one by one out of the aircraft, I'd expect them to at least initially fly forwards and then start manoeuvring towards the rear, if that was where their target was.  I cannot see them carrying sufficient fuel to simply blast rearwards, cancelling out their M2+ forwards momentum and then hitting M6 real quick.

[Mr.Creak]

With a stated range of 72 nm they'd have plenty of time to build up speed to M=6.5 from a "launch" velocity of M=2 in the opposite direction.

[Old Wombat]

Now, with some very basic research, I have the max. speed of the SA-2 at approx Mach 3.5; add to that my reading of the text as inferring a combined speed of Mach 7; then I conclude that the lenticular missile had a max speed similar to the SA-2 at about Mach 3.5.

Also, given its high-g loading spec's I would expect that if launched to attack to the rear the missile could use its entire surface area as a kind of massive air-brake, bringing it to a nearly instantaneous stop, before firing its rockets (?) and attacking the approaching SAM.

Of course, I could be wrong.

[Mr.Creak]

Now, with some very basic research, I have the max. speed of the SA-2 at approx Mach 3.5; add to that my reading of the text as inferring a combined speed of Mach 7; then I conclude that the lenticular missile had a max speed similar to the SA-2 at about Mach 3.5.

Huh?

Wiki:

Speed    Mach 6.5+

Directory:

Two solid-fueled rocket motors of 45.4 kN (10200 lb) thrust propelled the missile to a speed of Mach 6.5,

[Old Wombat]

My basic research included this wikipedia article for the S-75 "Dvina" (a.k.a. SA-2 "Guideline");

http://en.wikipedia.org/wiki/S-75_Dvina

Speed    Mach 3.5

and this Global Security article;

http://www.globalsecurity.org/military/world/russia/v-75-specs.htm

Max. velocity (Mach)    4.0 B/C/D, 4.5 E/F Mach

So, at best Mach 4.5, not Mach 6.5, according to my references.

I just went for the one that gave the lenticular its fastest possible speed, at worst, you're still looking at about Mach 2.5

[KJ_Lesnick]

Assuming it's not classified, was the agility of this missile such that fighters wouldn't have been able to avoid getting shot down?

[Mr.Creak]

My basic research included this wikipedia article for the S-75 "Dvina" (a.k.a. SA-2 "Guideline");
Etc

I fail to see the relevance, since the sources for the Pye Wacket give a speed for the Pye Wacket itself, not a combined closing speed.
E.g. if you buy a car with a claimed top speed of 60 mph would you accept the excuse "Yeah, well that only applies if you have an oncoming car doing 40 mph"?

Assuming it's not classified, was the agility of this missile such that fighters wouldn't have been able to avoid getting shot down?

According to both sources I linked to the Pye Wacket was highly manoeuvrable:

outstanding terminal agility

super-agility

I'll have to find my B-70 book and see if there's any further info in that.

[PR19_Kit]

What I want to know is who gave the thing such a STUPID name? 

Or was it in the usual American pattern of giving things confusing names just because they can?

[NARSES2]

What I want to know is who gave the thing such a STUPID name?  

Or was it in the usual American pattern of giving things confusing names just because they can?

And we didn't ? Blue cheese/Green cheese ? Cream carrot ? (I hope I made that one up  )