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Explain the optical gunsight to me?


jonatron5

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Ok after much Internet searching, reading the guides and the manual I feel as though I am no closer to understanding the ASP gunsight.

 

My main confusion comes from the fact that their exist 3 binary silver switches , to the left of the gunsight allowing for 9 different permutations of gunsight settings, and I have no idea what any of them do, next their are the two dials on the left and right to enter the targets wingspan, and I believe angle of approach to the target?

 

Can some give me a fairly simplified explanation of what I need to do to properly operate this gun sight?

 

How I need to set it so that it will pull lead for me in dogfights,

How to set it such that it will give me proper impact spot of my bombs/ rockets

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For dogfighting with guns, put the weapons switch on air, the top switch to guns, leave the other two alone (up).

 

You'll know you have it right because you'll get the gyro effect on the piper. Setting for bombs is pretty simple too. IIRC, just put the weapons switch to ground, middle asp switch to B, top on launch. The piper should disappear in level flight when in bombing mode.

 

I never touch the bottom switch or the dials. Slayed many AI with this configuration


Edited by Gunny Highway
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How I need to set it so that it will pull lead for me in dogfights

 

It won't. It's not designed to do that. Minimum radar ranging is 300 meters and manually you can't get much lower too. It's purpose is to help make strafing runs at the bombers and non manoeuvring targets or A2G attacks. For dogfights you're better off with the fixed net.

 

How to set it such that it will give me proper impact spot of my bombs/ rockets

 

Bombs - realistically, you can't. The CCIP mode for bombs is purely fictional, in real life you would adjust the gunsight angle using the right knob and manually release the bomb at the speed, angle and altitude given in the manual (which we don't have).

 

For rockets, set the weapons switch to ground, select rockets and leave the other switches in their default positions.


Edited by some1

Hardware: VPForce Rhino, FSSB R3 Ultra, Virpil T-50CM, Hotas Warthog, Winwing F15EX, Slaw Rudder, GVL224 Trio Throttle, Thrustmaster MFDs, Saitek Trim wheel, Trackir 5, Quest Pro

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Here is a nice bombing guide written by 159th_Royalman

 

With this method you can drop the bombs accurately 1,5-1 km from target. This allows you to remain relatively safe at altitude. Great for taking out T-72's. It needs to be practiced though.

 

 

Setting up your Run:

- Minimum altitude 3000 meters, otherwise you do not have enough time to aim at the target.

- 30-40 degree dive. Any less than 30 degrees will put you too close to the target!

 

 

Aiming:

During your dive keep the target between the 2nd and 3rd lower mark in the vertical scale of the Grid in your HUD. Once you get close enough the piper will appear from underneath and it will travel up your HUD. Simply press your release button when the piper is over the target. Pictures below.

 

Note: hold your release button down for a few seconds after the bombs released. Otherwise the second pair of bombs might fail to drop on your second attack.

 

Bomb1.png

 

Bomb2.png

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The above guide won't work if you have realistic ASP piper checked in DCS options.

Hardware: VPForce Rhino, FSSB R3 Ultra, Virpil T-50CM, Hotas Warthog, Winwing F15EX, Slaw Rudder, GVL224 Trio Throttle, Thrustmaster MFDs, Saitek Trim wheel, Trackir 5, Quest Pro

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You won't be able to really operate the sight as reality because it's not 100% correctly modeled yet. But it's not too far off to learn the basic concepts.

 

The "HO/PC" switch chooses what ballistics to assume for forward-firing weapons, "HO" cannon or "RS" rocket. Below that is the "C/B" switch which chooses between forward-firing "C" and free fall "B" weapons. If "B" is selected for bombing the position of the "HO/PC" switch is of no consequence; it only matters to further clarify which forward-firing weapon type is used.

 

Below those is the "AUTO/MAN" switch which determines if range (and a few other things) is calculated automatically from the radar or another sensor system or if it is entered manually by the throttle twist grip.

 

---

 

The left knob is actually 3 different inputs in one. The scale printed on the knob itself is used for the target span size "HO 300M" i.e. when using the cannon after twisting the manual range down to the 300 meters setting. The scale inside the window is really two scales: span size in meters when using the sight when the range is not set to 300m or reticle radius in milliradians. Which scale is in use depends on the configuration of other switches.

 

The angle knob on the right is for manually entering the vertical angle when manually positioning the reticle for rockets, guns, or bombing. The knob itself has reminder markings for common weapons angles (HO cannon, S-24 rocket, S-5 rockets, 1.5° for missiles, etc.).

 

--

 

For dogfights with cannon set the switches as follows:

HO/PC to HO

C/B doesn't matter

AUTO/MAN to MAN

CC/GYRO to GYRO

Rotate the throttle grip to the minimum range position

 

For rockets:

HO/PC to PC

C/B to C

AUTO/MAN to AUTO (or MAN if manually entering range and vertical angle)

CC/GYRO to GYRO (or CC if skill with gyroscopic reticle is unpracticed)

 

For bombs:

Same as rockets but AUTO/MAN must be MAN, CC/GYRO set CC, and angle knob set according to a bombing profile chart from a manual.

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Ok all very useful replies, I am very surprised to find out the gunsight does not have automatic radar guided leading, I know it's not the most technologically advanced fighter but it is Vietnam era after all.

 

But that point aside, someone raised the point of using the FixNet to try to determine lead to pull on target, I feel the need to ask, this now. I know how to turn the FixNet on, but I have no idea what it is, what it's showing me, what it represents etc.

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In the general case (not 300m fixed mode) the sight can use radar ranging to displace the pipper along with the electro-gyroscopic mirror float to produce an e.g. 630m cannon solution. This is good for attacking a B-52 under minor G loading with the cannon.

 

It's just that in dogfighting fighter type aircraft it is recommended to switch to 300m fixed range mode as the damping solenoids increase and it is suitable for high-G maneuvering.

 

Realistically the AG rockets shouldn't do a CCIP type ballistic solution. In automatic mode it should just dial in a "mean angular correction" which is the same as setting the sight in manual mode and cranking the vertical angle dial to match the angle marking for that weapon type. The validity of this particular angle only holds for a narrow range of speeds and slant ranges in AG rocket attack.

 

The only thing the "use realistic ASP pipper" does in options is prevent the AA missile pipper from jumping around the target (an unrealistic behavior). It has no effect for AG rocket shooting either way.

 

--

 

The standby reticle is controlled by the "I - II" switch on the lower right corner of the sight and the round brightness knob on the lower left corner. Realistically the brightness knob is the on/off/brightness control and the I-II switch changes between pattern 1 and 2, but in DCS the pattern switch is acting as on-off and the brightness knob only for brightness. This means we only get one of the two available standby reticle patterns.

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Realistically the AG rockets shouldn't do a CCIP type ballistic solution. In automatic mode it should just dial in a "mean angular correction" which is the same as setting the sight in manual mode and cranking the vertical angle dial to match the angle marking for that weapon type.

 

That's not true. While it may not be a "real" CCIP solution like in the A-10C, MiG-21 has a ballistic computer that calculates the firing solution for guns/rockets. It takes into account weapon ballistics, slant range to target (from radar in fixed beam mode or radio alt + pitch indicator), AOA and slip angle. Based on that it rotates the sight by a proper angle.

 

From what I can read it doesn't take aircraft airspeed into account, nor the wind. Also the rocket ballistic choice is set by maintenace crew, so realistically you shouldn't be able to mix A2G rockets of diffrerent types. But in a typical usage scenario it should work accurate enough as CCIP, so it's not far from what we have now.

Hardware: VPForce Rhino, FSSB R3 Ultra, Virpil T-50CM, Hotas Warthog, Winwing F15EX, Slaw Rudder, GVL224 Trio Throttle, Thrustmaster MFDs, Saitek Trim wheel, Trackir 5, Quest Pro

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These are the manual quotes I am looking at and relying on Google translate:

Celownik jest obliczony dla szeregu balistyk, lecz jednorazowo wylicza poprawki kątowe tylko dla jednej z nich (dla jednego typu broni).

 

Podczas strzelania z działko do celów naziemnych i powietrznych celownik automatycznie wylicza w zakresie "Żyro" poprawki kątowe na kąt wyprzedzenia i celowania, a przy strzelaniu do celów powietrznych niekierowanymi pociskami rakietowymi S-5M jeszcze dodatkowo poprawkę na kąt zwłoki.

 

W celu rozwiązanie zadania celowania przy odpalaniu kierowanych i niekierowanych pocisków rakietowych oraz strzelaniu z działko do celów powietrznych, do celownika jest wprowadzana automatycznie, po przechwyceniu celu, bieżąca wartość odległości w postaci napięcia prądu stałego z samolotowej stacji radiolokacyjnej RP-22SMA.

 

Przy odpalaniu niekierowanych pocisków rakietowych (RS) do celów powietrznych i naziemnych, do celownika są wprowadzane automatycznie bieżące wartości kątów natarcia i ślizgu w wyniku sprzężenia celownika z nadajnikiem katów natarcia i ślizgu DUAS-69-20-5M. DUAS wprowadza do celownika kąty natarcia w zakresie od 0° do 9°, a kąty ślizgu w zakresie ±3°.

 

Sumaryczne poprawki kątowe kąta wyprzedzenia, celowania i zwłoki są zależne od wielkości czasu przeliczeniowego T, który jest zależny od odległości, wysokości lotu, charakterystyk balistycznych broni, jak również od kąta natarcie i ślizgu.

 

Moment przechwycenia celu przez RLS sygnalizuje lampka sygnalizacyjna z zielonym filtrom, znajdująca się z lewej strony skal bieżącej odległości na głowicy celownika.

 

Przy braku lub zerwaniu sygnału “PRZECHWYCENIE”, celownik w zakresie “Żyro”. “Powietrze”, “Automatyczne” wylicza odległość ustalona do celu 600 - 650 m.

 

W przypadku uszkodzenia samolotowej stacji radiolokacyjnej odległość w zakresie od 0,4 do 2,0 km można wprowadzać do celownika ręcznie, wykorzystując dalmierz optyczny z zewnętrzną bazą, przez obrót potencjometru umieszczonego na dźwigni sterowania silnikiem. Dla ułatwienia celownika podczas strzelania z działko z malej odległości do celów powietrznych, do celownika wprowadza się odległość ustalona 300 m. Moment otwarcia ognia określa się “opisaniem” celu przez pierścień dalmierzy, którego wielkość ustawia się dodatkowej podziałki (zewnętrznej) naniesionej na pokrętle “BAZĄ”, odpowiednio do rozpiętości celu.

That suggests in gyro the angle is generated with some sophistication like you say. But in this following quote it picks a static angle for the weapon. The difference I think is GYRO or CC.

 

Podczas strzelania do celów naziemnych (w zakresie “SS”, “AUTOMATYCZNE”, “ZIEMIA”) celownik wypracowuje automatycznie uśrednione poprawki kątowe na kąty celowania i natarcia: 0°40’ dla GSz-23, 1°04’ dla S-5M(5k) i 1°45’ dla S-24, które są naniesione na pokrętle “KĄTY”.
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Setting the switch to CC (translated to "SS") disconnects the gyros effectively caging the piper. Then the fixed average angles are set automatically as descibed. Similar situation happens when there is no information from DUAS sensor (no AoA and sideslip).

Hardware: VPForce Rhino, FSSB R3 Ultra, Virpil T-50CM, Hotas Warthog, Winwing F15EX, Slaw Rudder, GVL224 Trio Throttle, Thrustmaster MFDs, Saitek Trim wheel, Trackir 5, Quest Pro

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There are two fixed reticles but almost identical. One is just an abbreviated form of the other. The reticle features are just lines defined by particular sizes in milliradians.

 

The DCS reticle adds in an "X" or two slightly depressed along the centerline. The upper one is the cannon bore and the lower one is the fixed beam radar LOS. I think they are at 11.5mil and 1.5° respectively.

90690145.thumb.jpg.de73a6b4d93a567acd00deb3dc7f3305.jpg

MiG-21F-ASzP-jhzu.jpg.5959601cf6bd825ce5657c7a73964582.jpg

1765457469_Fig24SightFixedReticles.thumb.gif.574685fc7cb380a2449d2d322cedcf4f.gif

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Just small explanation. "Abbreviated form" was first reticle used in ASP-PFD from 1968 to 1972. After 1972, when new missiles show-up ( R-60, R-13M ), gunsight got additional transparent range scale and this new "full" reticle. During 70's many early ASP-PFD were modernized to late standard ( WP M's and MF's and Soviet SM's and SMT's) .

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OK. I am still understanding all ASP switches. I was thinking one switch is changing between two patterns. Switches marked "1<-->2" which in DCS are turning on the reticle lamp I know is somehow wrong. Lamp filament switches are for switching to a backup or alternate filament in case of breaking? Is light quality different changing filament 1 or 2?

 

Since DCS has ASP-PFD-M instead of ASP-PDF-21 (or whatever is the model name for new and old) it should have the full reticle instead?

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OK. I was thinking one switch is changing between two patterns. Switches marked "1<-->2" which in DCS are turning on the reticle lamp I know is somehow wrong. Lamp filament switches are for switching to a backup or alternate filament in case of breaking? Is light quality different changing filament 1 or 2?

 

Yes, that switch change from main filament ( No. 1 ) to emergency filament in case of no. 1 failure. No difference between them in light quality.

 

Since DCS has ASP-PFD-M instead of ASP-PDF-21 (or whatever is the model name for new and old) it should have the full reticle instead?

 

Honestly, I never heard name ASP-PFD-M ( according manuals MiG-21's had ASP-PF-21, ASP-PFD-21 ( early, late ) and ASP-PFD-21A ). Considering, that we have MiG-21Bis module, yes we should have late "full" reticle. I even was thinking about made new texture for this reticle.

 

I checked "papers" and photos, and I made mistake in my last post. Reticle story: ASP-PF "partial pattern", ASP-PFD "full" reticle and later with new missiles, again "partial" reticle with new pattern.


Edited by foxbat155
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