DRDO, PSU and Private Defence Sector News

south block

up your a**
New Member
Joined
Feb 1, 2016
Messages
996
Likes
1,471
Country flag
EQ6zM8sW4AUJoOY.jpeg


Topol- M ICBM first stage using grid fins for Maneuvering along with TVC damn! ---- Agni -5 use only TVC --- russian ICBMs are a beast ---- k 4 also used grid fins for Maneuvering right ? @porky_kicker
 

porky_kicker

New Member
Joined
Apr 8, 2016
Messages
6,030
Likes
44,621
Country flag
View attachment 43494

Topol- M ICBM first stage using grid fins for Maneuvering along with TVC damn! ---- Agni -5 use only TVC --- russian ICBMs are a beast ---- k 4 also used grid fins for Maneuvering right ? @porky_kicker
I don't think those grid fins are for maneuvering the missile.

Look at the grid fins

Each fin is attached to 2 points , so cannot rotate axially to enable change in direction of flight

Each fin has no attached control mechanism to open them or close them except by aerodynamic flow

The grid fins are at the top side of the stage , not at the rear

Why ?

Look at the 2 fixtures holding each grid fin , top side of each fixture has a restrainer to hold the fins at 90 degree horizontal position as the aerodynamic flow upwards pushes against the closed fin to deploy till 90 degree and then due to the restrainers the fins are constantly held at a horizontal postion ( 90 degree ) due to the constant upwards flow of air ( conversely downward descent of stage )

This is for controlled descent of the seperated stage upon stage seperation.

ISRO has incorporated similar technology ( grid fins ) in its manned escape module. The aim is to have controlled descent of the discarded stage.
 
Last edited:

south block

up your a**
New Member
Joined
Feb 1, 2016
Messages
996
Likes
1,471
Country flag
I don't think those grid fins are for maneuvering the missile.

Look at the grid fins

them except by aerodynamic flow

The grid fins are at the top side of the stage , not at the rear
They are at rear side of stage probably for stabilization or Maneuvering ?

main-qimg-4943f32b5041e60aaad1738015858ede.jpeg

main-qimg-b5b158d73a9c7a8b6554d3b7db7b7913.jpeg
---- do you have actual model of what K- 4 look like ?
 
Last edited:

south block

up your a**
New Member
Joined
Feb 1, 2016
Messages
996
Likes
1,471
Country flag
Ok found some details -----
All three stages are made of composite materials. During the first stage operation the flight control is implemented through four aerodynamic and four jet vanes. Four similar trellised aerodynamic surfaces serve for stabilization.
@porky_kicker
Each fin is attached to 2 points , so cannot rotate axially to enable change in direction of flight
only four fins see

Screenshot_20200223_032050.jpg


so it does use grid fins for Maneuvering along with stabilization.
 
Last edited:

porky_kicker

New Member
Joined
Apr 8, 2016
Messages
6,030
Likes
44,621
Country flag
@porky_kicker I edited my post --- those grid fins doesn't just look for control landing but probably has a dual purpose.
Well I am at loss to explain the same .

I knew about grid fins being used for controlled decent or for high AoA .

But I am uninformed about its utility in this particular case.

K4 uses nothing of this sort , atleast I am not aware of .
 

porky_kicker

New Member
Joined
Apr 8, 2016
Messages
6,030
Likes
44,621
Country flag
Yes I didn't mean grid fins but this...

View attachment 43523

Where are these things used --- in which stage?
These were described as control surfaces for kfour

But which portion they are used is not known.

Given the shaping of the fin i doubt it's for any of the stages. And definitely not on the nose section either whose pic don't show it . So possibly it's for the RV.

Fair warning Location is total speculation
 

Global Defence

Articles

Top