Ask anything Thread (Air Force)
- Thread starter Jeff Head
- Start date
Ha, ha, ha!Hi,
Are you comparing the PLAAF J20 to the Tonka Toy J20 in your play pen----????
This is the level of discussion we're dealing with. One troll thinks the J-20 can't eject missiles at supersonic speeds and another thinks it can by crashing them into the plane.
?
For ventral weapon bays of F-22, weapons are launched via trapeze style ejector hardpoints to push the weapon out of the bay into the airstream. For F-35's "deep" hardpoints in each of its two weapon bays it is the same.
We have pictures of F-22's hardpoints and what it looks like:
We also have had pictures of J-20's hardpoints in the past as well:
Based on the geometrical similarity of F-22 and J-20's ventral weapons bay and the pictures we've had of J-20's hardpoints compared to F-22's hardpoints that are trapeze in nature, the most logical conclusion would be that J-20's hardpoints are trapeze in nature to push the weapons out from the weapons bay into the airstream as well.
Without such a function, it would be impossible to deploy weapons because they can't rail launch missiles from the ventral weapons bay like they do for the J-20's side PL-10 bays because obviously the ventral hardpoints aren't long enough to support it. The only logical answer would be an F-22-esque solution to similarly push missiles out into the airstream.
Here is a clear picture of how F-22's hardpoint trapeze launcher for AMRAAM works
and a similar concept (I actually believe this one below is the one chosen for production F-22s):
In addition, the F-35's door/swing hardpoints also have an ejection mechanism to eject the AMRAAM into the airstream (its deep hardpoints in each weapons bay has a similar mechanism).
The video below demonstrates how F-35's door/swing hardpoints works in a rather straight forward way, at time 1:24. Again, note the push out mechanism.
For separations of any munition from the host aircraft, you cannot simply eject the weapon from its hardpoint using gravity.
You either need to launch the missile off the rail directly (for example that is how most SRAAMs are launched, where the motor is ignited while it is still on the rail. AMRAAMs can also be launched off the rail directly).
Or, for many other missiles and bombs, your hardpoint has a built in ejection mechanism to push the weapon away from the airframe sufficiently before its motor ignites so that the weapon doesn't end up crashing into your own airplane if your aircraft is maneuvering.
For example, here's an ejection style launch of a meteor from a Typhoon, and from multiple angles in slow you motion you can see two arms built into the hardpoint itself push the missile downwards from the hardpoint and aircraft before the motor ignites.
Here's a gif of a YJ-12 launch from an H-6 that clearly shows the large trapeze style arms pushing the weapon away from the aircraft. Given the size of the missile, that would explain the larger arms to more forcefully push it away.
You can actually see the flash as the missile's motor ignites once it has sufficient clearance from the aircraft.
This isn't exactly new technology, so I'm confused as to why Inst writes about this as if this kind of launch is unique to US stealth fighters.
Mechanical push/trapeze hardpoints to push missiles away from their aircraft into the airstream is very old technology with many applications on multiple types of platforms around the world for decades if not longer.
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In the US version, however, the trapeze launchers take up considerable space in each of the weapons bays. The SDB IIs, for instance, are not directly mounted onto the weapons bay, but onto a launcher attached to the weapons bay.
Image of the J-20 production model's weapons bay. Seems as though just letting gravity or windshear do its work might be more efficient in this case.
Image of the J-20 production model's weapons bay. Seems as though just letting gravity or windshear do its work might be more efficient in this case.
In the US version, however, the trapeze launchers take up considerable space in each of the weapons bays. The SDB IIs, for instance, are not directly mounted onto the weapons bay, but onto a launcher attached to the weapons bay.
Image of the J-20 production model's weapons bay. Seems as though just letting gravity or windshear do its work might be more efficient in this case.
.... Are you serious?
That picture obviously shows the aircraft doesn't have any trapeze hardpoints equipped in its weapons bay; the hardpoints are not fixed and integrated into the weapons bay; they are removable.
Here's a picture of an F-22 with all six of its trapeze hardpoints attached:
Here's a picture of an F-22 with only four of its six trapeze hardpoints attached:
Where did the other two go?? Well, they're not permanent fixtures, they're detachable, and can be fitted when needed just like hardpoints on any other combat aircraft!
Here's a picture of J-20 with two missiles in one half of the bay (one with fins, one without; both almost certainly on hardpoints), whereas the other half of the bay has two hardpoints that looks consistent with what a trapeze hardpoints would look like.
Your J-20 image shows its weapons bay doesn't have any trapeze hardpoints, yes. Because they're not permanent fixtures and can be removed.
We've seen pictures of J-20s with hardpoints consistent with what we'd expect them to look like in its weapons bay.
Therefore, the only logical answer is that J-20 has trapeze hardpoints to deploy its weapons from its internal weapons bay, and like hardpoints of other combat aircraft, they are removable and not permanent.
I really hope you aren't trolling me right now or if you are genuinely making the argument that you believe hardpoints are permanent fixtures.
Version with the PL-15s loaded into the J-20s.
Yes, and those PL-15s will be attached to the weapons bay by trapeze hardpoints. I hope you're not arguing that because we cannot see the hardpoints that they are not there, considering we know what they look like and how big they are, where if they did carry missiles it would completely obscure the view of the hardpoints from virtually all outside photo angles.
Unsurprisingly, this picture of an F-22 carrying AMRAAMs we are also unable to see their trapeze hardpoints, because the missile is larger in length and width compared to each hardpoint it is attached to, which should be very obvious even at a cursory glance at the size of an AMRAAM vs its hardpoint.
Even this closeup of an F-22's weapons bay doesn't show the hardpoint that the AMRAAM is attached to, despite the much flatter angle of the picture.
I don't understand why you like so much to bring up 2001 and the prototype weapons bays. Also, I'll bring up that in the F-22 case, the SDBs have a specific launcher attached to the hardpoints on the F-22, that's distinct from the AIM-120 launchers.
My point is more that the trapeze hardpoint set-up with the F-22 is inefficient and it's possible the J-20's use of direct-drop or aerodynamic push might increase usable bay space alongside decreasing aircraft weight.
My point is more that the trapeze hardpoint set-up with the F-22 is inefficient and it's possible the J-20's use of direct-drop or aerodynamic push might increase usable bay space alongside decreasing aircraft weight.
Airframe s/n 2002 (not 2001) demonstrated the existence of trapeze hardpoints for carrying PL-15 missiles. Naturally it follows that such hardware will have been developed to be used for production aircraft as well, considering what we know about the importance of trapeze hardpoints for separation of stores from aircraft, including stealth fighters. The pictures of s/n 2002's weapons bay is hard proof of equipment that is visually consistent with what we would expect such trapeze hardpoints to appear like.
I think I am more confused as to why you think it is unimportant -- in fact I am confused as to how you can even make your argument considering such a picture exists.
As for space efficiency -- unless J-20 has some strange mechanism whereby it is able to equally reliably allow separation of its payload from its weapons bay in a way that is not inferior to trapeze hardpoints, then I expect it to be using the trapeze hardpoints we saw on s/n 2002 or an evolution of it.
Considering the likes of F-22 and F-35 continue to use trapeze hardpoints and with no plans of replacing them with different hardware, there is no reason to assume J-20 has somehow made a breakthrough in that regard.
Taking this post together with my prior replies, what it means is that we have overwhelming indications and logic to argue that J-20 almost certainly has trapeze hardpoints to deploy weapons from its internal weapons bay.
(As for SDBs -- it has a different hardpoint arrangement that takes the place of two AMRAAMs and their associated trapeze hardpoints. 4 SDBs+1 single unified SDB hardpoint replaces 2 AMRAAMs+2 AMRAAM trapeze hardpoints. I'm not sure what your point is here. We know that SDBs rely on ejection as well for separation as well on other aircraft, so we have no reason to expect the F-22's SDB hardpoint would not also have that function )
TerraN_EmpirE
Tyrant King
I think you might have missed something...
If this was a world war era bomber sure. The Problem is you need to be able to fire that missile in a turn, Dive, bank or even upside down. That’s going to cause problems. If you are pulling negative G forces IE because of the maneuver the force of inertia is pushing counter to the normal pull of gravity so instead of being pulled to the ventral of the fighter you are being pushed to the Dorsal. You hit That pickle what happens?
The weapon is pushed into the fighter not out of the fighter.
Because the fighter isn’t operating in the straight and level flight mode but is supposed to be turning and maneuvering you need to have a means of Ejection of weapons that can operate in both positive and negative G forces.
Some maneuvers of a fighter are going to put you in Positive G where in you are pushed down, this for the pilot risks a Grey out as blood rushes to the feet. For dropping you Missile fine it goes right out.
Some produce neutral G where in the force of gravity is effectively countered. Push that pickle it stays right there.
Some produce Negative G you are pushed up and risk a red out and so you hit That button and it’s going to stay again in the fighter. And G forces don’t just pull or push up and down either they can also push back and forward or side to side.
So your gravity release has a major flaw here. You hit That release door opens but in a dive the weapon doesn’t leave the door closes you pull out and now you have a dead weight rattling around in the fighter with a rocket engine about to fire surrounded by fuel and its siblings.