• Hi Guest! Forum rules have been updated. All users please read here.

ASP-17 gunsight for MiG-23, Su-17/22/25, etc.

Dilbert

ACCESS: Confidential
Joined
Jan 3, 2006
Messages
81
Reaction score
8
An old question, but repeated somewhat more clearly now with some photos from Alexander Mladenov's article on Su-22 in IAPR #18:

How does it work? Can we really believe the ASP-17 gunsight pipper can aim "30 degrees down," when no portion of the gunsight combiner glass seems to extend below the horizon at all? Why does the text say the gunsight "fills the front windscreen," when in fact it seems to leave an elephant-sized gap at the bottom? Isn't that where ALL bullets, bombs, rockets and missiles should go? Who cares about filling the TOP of the windscreen (which the ASP-17 seems admirably well-shaped to do)? How does this thing aim at all? And if it works, then why do modern HUDs need to extend all the way to the bottom of the windscreen to accomplish the same bombing tasks? ???

Sincere questions - no slam against Sukhoi intended.

Yet.
 

Attachments

  • su25gs2.jpg
    su25gs2.jpg
    118.9 KB · Views: 332

Vati

ACCESS: Restricted
Joined
Dec 19, 2006
Messages
1
Reaction score
0
On the picture you had attached, the sight is in extended position. The combiner glass can be moved up and down.
 

mrdetonator

ACCESS: Secret
Joined
Jan 8, 2006
Messages
215
Reaction score
11
Website
www.lietadla.com
Dilbert said:
An old question, but repeated somewhat more clearly now with some photos from Alexander Mladenov's article on Su-22 in IAPR #18:

How does it work? Can we really believe the ASP-17 gunsight pipper can aim "30 degrees down," when no portion of the gunsight combiner glass seems to extend below the horizon at all? Why does the text say the gunsight "fills the front windscreen," when in fact it seems to leave an elephant-sized gap at the bottom? Isn't that where ALL bullets, bombs, rockets and missiles should go? Who cares about filling the TOP of the windscreen (which the ASP-17 seems admirably well-shaped to do)? How does this thing aim at all? And if it works, then why do modern HUDs need to extend all the way to the bottom of the windscreen to accomplish the same bombing tasks? ???

Sincere questions - no slam against Sukhoi intended.

Yet.
The ASP-17BC(Su-22UM3,Su-25K) gyro-gunsight is a complex optical, mechanical, electrical device, which comprises the gunsight head S-17VG(actually you see it in the cockpit), the ACVU an analog computer unit counting the neccessary targeting deflections and other electronic blocks cooperating with aircraft flight/nav/weapon systems. Those electronic blocks and the ACVU unit are hidden in the airframe.
As you know the weapon system of the Su-22M4/UM3, Su-25K comprises also the laser designator KLEN-PS. Both targeting devices the KLEN-PS and the ASP-17BC(actually the S-17VG) have their own aiming angle limits in azimuth and elevation. When you take into account only maximal limits of both, you get the limits, +/-12deg in azimuth, up 6deg/down 30deg in elevation. You are telling the total limits of the targeting systems. The transparent S-17VG glass in mountend on kinematic assembly which moves up and down. The S-17VG glass is changing according to type of weapons you want to use and it has eleven fixed posiitons.
The Su-22M4 is equiped with the S-17VG gunsight head only. The rest, mainly the ACVU computer was replaced by the CVM-20-22 digital computer(a part of the PRNK-54 nav/targeting system)

The Older gyro-gunsight ASP-17ML fitted in the Mig-23ML has to my knowledge only two glass positions, the upper and lower one. The upper one is used for cannon, unguided-guided missile firing, the lower one mostly for bombing.

The ASP-23DE gyro-gunsight used on the Mig-23MF is the predecessor of the ASP-17 familly gunsights.
 

crossiathh

ACCESS: Confidential
Senior Member
Joined
Jan 17, 2006
Messages
58
Reaction score
7
May I can add something noteworthy here:

Compared to the ASP23D(Export) of MiG-23MF the ASP-17ML(Export) of the MiG-23ML was provided, amongst other things, with two very helpfull features for close air combat.

1. With the introduction of the R-60 or R-60M a short ranged dogfight missile was available with a off-boresight angle of about +/- 12° respectively +/-20° (different to their predecessors R-3S or R-13).
Normally the seeker head could be steered by either the radar, the IRST or it was used in boresight mode, which were not helpfull in close dogfight. With the ASP-17ML an additional possibility was introduced.
The pilot could steer the seaker head manually by using the knob normally used to control the X-23M missile (left on the stick) to shift the aiming circle onto the target (+/-20°). Useless to say that this provides some elbow-room while in turning fight. A very small step in the direction of HMS.

2. The ASP-17ML was provided with a new gunsight besides the still implemented gyro-gunsight, which computed the aiming point. It was told to be fairly accurate.
 

Dilbert

ACCESS: Confidential
Joined
Jan 3, 2006
Messages
81
Reaction score
8
Ok, thanks for interesting replies... Eleven positions sounds rather complex, for a task that can probably be done with two (or one, if the gunsight were larger), but I guess that fully answers the question. I'm surprised that there seems to be no manual available for this plane.
 

mrdetonator

ACCESS: Secret
Joined
Jan 8, 2006
Messages
215
Reaction score
11
Website
www.lietadla.com
Dilbert said:
Eleven positions sounds rather complex, for a task that can probably be done with two (or one, if the gunsight were larger), but I guess that fully answers the question. I'm surprised that there seems to be no manual available for this plane.
Well, what looks like a "complex nonsense" to you is actually a simple and cost effective solution how to get rid of problems that were occuring on single combiner head-up-displays (cathode ray tube) during that time. The servo-driven single combiner of the S-17VG eliminate geometric distortions and optical aberrations of a wider-angle single combiner. You either could make a very expensive and non-maintenance friendly high-grade optics(prism, mirrors, combiner glass) or find out a cheaper and better solution. Otherwise you end up with focus errors, reticle fuzziness or ghosting problems at the outer sections of the combiner. This all makes aiming harder and inaccurate, especially during air to ground tasks.
Dilbert said:
I'm surprised that there seems to be no manual available for this plane.
You should not be, the primary role of the Su-22 was a "nuclear striker", therefore access to manuals had officers with higher security clearance. Anyway, what availability are you talking about, there is no officially available russian aircraft manual at all.
 

Tompa

ACCESS: Restricted
Joined
Feb 15, 2006
Messages
5
Reaction score
1
Two nice photos of an ASP-17 (don't know which version, though) from Ethiopian MiG-23BN can be found here: http://forum.keypublishing.co.uk/showthread.php?t=78226. There is also some interesting text there, although not related to the sight itself.
 

aggressor

ACCESS: Restricted
Joined
Mar 3, 2020
Messages
2
Reaction score
0
Dilbert said:
An old question, but repeated somewhat more clearly now with some photos from Alexander Mladenov's article on Su-22 in IAPR #18:

How does it work? Can we really believe the ASP-17 gunsight pipper can aim "30 degrees down," when no portion of the gunsight combiner glass seems to extend below the horizon at all? Why does the text say the gunsight "fills the front windscreen," when in fact it seems to leave an elephant-sized gap at the bottom? Isn't that where ALL bullets, bombs, rockets and missiles should go? Who cares about filling the TOP of the windscreen (which the ASP-17 seems admirably well-shaped to do)? How does this thing aim at all? And if it works, then why do modern HUDs need to extend all the way to the bottom of the windscreen to accomplish the same bombing tasks? ???

Sincere questions - no slam against Sukhoi intended.

Yet.
The ASP-17BC(Su-22UM3,Su-25K) gyro-gunsight is a complex optical, mechanical, electrical device, which comprises the gunsight head S-17VG(actually you see it in the cockpit), the ACVU an analog computer unit counting the neccessary targeting deflections and other electronic blocks cooperating with aircraft flight/nav/weapon systems. Those electronic blocks and the ACVU unit are hidden in the airframe.
As you know the weapon system of the Su-22M4/UM3, Su-25K comprises also the laser designator KLEN-PS. Both targeting devices the KLEN-PS and the ASP-17BC(actually the S-17VG) have their own aiming angle limits in azimuth and elevation. When you take into account only maximal limits of both, you get the limits, +/-12deg in azimuth, up 6deg/down 30deg in elevation. You are telling the total limits of the targeting systems. The transparent S-17VG glass in mountend on kinematic assembly which moves up and down. The S-17VG glass is changing according to type of weapons you want to use and it has eleven fixed posiitons.
The Su-22M4 is equiped with the S-17VG gunsight head only. The rest, mainly the ACVU computer was replaced by the CVM-20-22 digital computer(a part of the PRNK-54 nav/targeting system)

The Older gyro-gunsight ASP-17ML fitted in the Mig-23ML has to my knowledge only two glass positions, the upper and lower one. The upper one is used for cannon, unguided-guided missile firing, the lower one mostly for bombing.

The ASP-23DE gyro-gunsight used on the Mig-23MF is the predecessor of the ASP-17 familly gunsights.
Hey man thanks for you information ; im looking for su24 gunsight information and also a picture of it when its active or in action if you have any information or photo of it i would be thankful to share on
 

Similar threads

Top