reported GAR-8 / AIM-9B Guidance Activation Time

[Curly]

Problem :

 After the GAR-8 is launched, it takes about 2 seconds before the missile will begin to maneuver to intercept the target it is tracking. The GAR-8 in game may also not pull enough G.  According to various official sources, The missile should begin to maneuver 0.5 seconds after it leaves the rail and pull up to 12 g. 

Details Below.

 

The GAR-8 and the Sidewinder B are the same missile. Per the 1971 Air Force Data Sheet for the GAR-8.

According to the Declassified 1966 Manual for Sidewinder B the missile should begin to maneuver 0.5 seconds after firing.

 

https://archive.org/details/OP23093rdAIM9B

 

The manual describes the operation of the missile:

The Time line for the operation of the missile is as follows. 

1. The Trigger is pulled,  The seeker gyro / gimbal is unlocked.

The seeker has +-30 degree FOV. 

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And will track the target through +-30 degrees.

2. 0.8 seconds after the trigger is pulled, the missile leaves the rail. The seeker is tracking the target. However maneuver commands are inhibited

3. 0.5 seconds after the missile has left the rail; Steering capabilities are initiated, as command signals are applied to the control servos. The missile will now pull up to 12g's to intercept the target.

 

21 seconds after launch; Guidance stops as the gas generator burns out.

24 seconds after launch; the missile self destructs.

What I think is happening in game is,

1.the missile comes of the rail instantly,

2. maneuvering is prevented until the time of flight is +1.2 to 2 seconds.   

3. After 1.2 to 2 seconds the missile begins to track the target.

Meaning that, Either maneuvering is being inhibited for too long or the missile is not pulling enough G to intercept after it leaves the rail.

The result of the current implementation is; Shots which are within parameters miss, because of the missile is prevented from maneuvering for to long, or wont pull enough to intercept it's target.

Attached is a track which illustrates this. In this mission I've attached a 4000 foot zone to a non maneuvering MIG 15. Shooting from within 4000 feet will give the missile a time of flight of 1 to 2 seconds depending on the closure rate. When firing the GAR-8 with good tone, within 4000 feet, and within the seekers +-30 degree FOV, the missile will not track. Kills can be achieved but the missile has to be ballistically aimed. IE it functions like a rocket with a proximity fuse.

In closing, the GAR-8 should be pulling up to 12 g's 0.5 seconds after it leaves the rail.  

 

Gar 8 test.trk

[iFoxRomeo]

Thank you Curly!

[2alpha-down0]

It appears that the missile doesn't start tracking until after the motor burns out, which always seemed odd to me.  Thanks for digging this up.

I don't think this is specific to the Sabre, as the missile performs similarly when fired from other aircraft.  This may need to go in the Weapon Bugs section.

Edited December 8, 2021 by 2alpha-down0

[Northstar98]

1 hour ago, 2alpha-down0 said:

It appears that the missile doesn't start tracking until after the motor burns out, which always seemed odd to me.  Thanks for digging this up.

I don't think this is specific to the Sabre, as the missile performs similarly when fired from other aircraft.  This may need to go in the Weapon Bugs section.

Agreed, it's a general problem with the missile in particular.

But awesome work OP on sourcing documentation, this should be able to be corrected.

[2alpha-down0]

@Flappie @NineLine Pretty decent documentation here.

[Flappie]

Excellent reporting, @Curly.

Issues reported.

[MiG21bisFishbedL]

Curly is a champ, I swear.