R-77 insane drag

[BlackPixxel]

Carrying a loadout of just 6 R-77 accelerates almost as slow as a loadout of 6x R-27R + 4x R-73. Which is almost a ton heavier on total (~900 Kg) and has bigger diameter missiles with large fins plus the additional R-73 with more flat IR seeker window.

Meanwhile a loadout of 6x R-27 is leaving the 6x R-77 in the dust in terms of acceleration.

This can not be right.

[Skuva]

Bluefor mains raiding your thread to explain how grid fins should give the missile the aerodynamics of a HD bomb in 3... 2... 1...

[Pavlin_33]

On 5/18/2024 at 1:06 PM, Skuva said:

Bluefor mains raiding your thread to explain how grid fins should give the missile the aerodynamics of a HD bomb in 3... 2... 1...

I think after seeing R77-1 in action IRL this is no longer an argument.

[Irisz]

You can read more about it here: https://apps.dtic.mil/sti/pdfs/ADA509444.pdf

Unfortunately, the R-77 missile has some disadvantages!

[GGTharos]

On 5/20/2024 at 4:24 PM, Pavlin_33 said:

I think after seeing R77-1 in action IRL this is no longer an argument.

It is an argument but it also doesn't matter in this case - AFAIK the fins would be folded until the missile is launched.   It's hard to say what the drag should be (eg. on some stations a sidewinder might have more drag than a 120) but it certainly seems odd that the R-77's would be that draggy on the pylons.  I suspect it's a case of drag factor copy-paste OR maybe for FC3 aircraft, there's no real distinction for weapons on pylons.

[AeriaGloria]

On 5/30/2024 at 4:09 AM, GGTharos said:

It is an argument but it also doesn't matter in this case - AFAIK the fins would be folded until the missile is launched.   It's hard to say what the drag should be (eg. on some stations a sidewinder might have more drag than a 120) but it certainly seems odd that the R-77's would be that draggy on the pylons.  I suspect it's a case of drag factor copy-paste OR maybe for FC3 aircraft, there's no real distinction for weapons on pylons.

If you mean original R-77 RVV-AE and R-77-1, I haven’t seen anything but speculation about the wings folding. Is there any evidence? 

[GGTharos]

Fair point, I only see them unfolded in images where they're mounted on pylons.  Chances are they're not all captive-carry, in which case perhaps the folding mechanism is only used for storage and transport, but then ... how do you fit them inside the Su-57 bay?  Maybe you don't.

Edited June 13, 2024 by GGTharos

[draconus]

13 minutes ago, GGTharos said:

how do you fit them inside the Su-57 bay?  Maybe you don't.

From wiki:

Quote

For air-to-air combat, the Su-57 carries four beyond-visual-range missiles in its two main weapons bays and two short-range missiles in the side bays. The primary medium-range missile is the active radar-homing R-77M (izdeliye 180), an upgraded R-77 variant with AESA seeker, dual-pulse motor, and conventional rear fins.

Quote

The Su-57 has two tandem main internal weapon bays each approximately 4.4 m (14.4 ft) long and 0.9 m (3.0 ft) wide and two side weapon bays with triangular section fairings under the fuselage near the wing root.

R-77 diameter 700-750mm (folded 300mm).

I read in other sources grid fins can be folded but only for carriage/transport off the aircraft.

Edited June 13, 2024 by draconus