JF-17 Thunder Discussions

Could be trying to maintain 1G if you’re fast enough

I am typically fast. I like to accelerate to 500kts and then pull nose to 20-25 degrees. By the time I slow down to 300kts, Jeff is 26k+ft. From here I reduce to mil power, turn on autopilot and let it climb to 32k. Before autopilot I notice that I have to keep hand on stick with slight downwards pressure to prevent stalling.

Yeah that’s probably from trimming to 1 G. At 45 degrees only half of your G force is deflected downwards by the perspective of a fixed to the airframe 6 axis gyroscope/accelerometer. The FBW only cares about downwards G(as seen on HUD) in this case not forward/backward G(since the other half of your G at 45 degrees pitch is being deflected backwards). So at 45 degrees attitude FBW commands pitch up to maintain 1G even if that doesn’t keep the same attitude, as long as your speed is high enough for FBW to be in G command law

shaHeen, are you sure what you notice is the FPM (Flight Path Marker) rising while the cross, indicating nose position, is fixed? Only when you are established in a climb with the pitch set, as seen by a steady cross, will the FPM remain steady. Even then it will change over time because both your climb rate and airspeed must change during a constant speed climb. A constant rate climb creates different relationships. Both types use a fixed power setting, MIL in this case.

A great demonstration of this effect can be seen during a takeoff. Start with a heavy aircraft, close to max GW, and use full burner. Rotate to 10 degrees on the cross at about 140 KCAS. The aircraft will fly off the ground when it's ready. Maintain that attitude but watch what the FPM does. Once airborne raise the gear and the pitch, cross, to 12 degrees and stay in burner. Approaching 350 KCAS reduce power to MIL, place the FPM to about 7-8 degrees, and then maintain 350 KCAS with pitch. The FPM will slowly drop as you adjust pitch to maintain airspeed. The difference between them will change too.

(This is my standard takeoff and climb profile. I maintain 350 KCAS until M .80 then maintain it. Of course, when departing at MGW you won't get very high or that fast without burning a lot of gas or dropping iron. I need to try 400 KCAS to M .80 for a climb profile when I want to use higher altitudes. One of these days I do some testing.)

You will be in a constant speed climb. Continuously adjust pitch to maintain 350 KIAS and watch the relationship of the cross and FPM. You may gain some insight into what is happening between the cross and FPM as you climb. I also think you may find you should stay off the pitch trim.

I can honestly say that I have never had to use the pitch trim in the Jeff. Aileron trim and a bit of rudder is necessary to compensate for asymmetric loading after dropping a single bomb but that's all. the aircraft should trim itself to 1G and remain at 1G. It doesn't happen instantly but even after heavy maneuvering it will quickly catch up. It is far, far better than the F/A-18. The F-16 should be the same as I think the Hornet should be but not so much in my experience. This is one of the really nice features of digital FCSs.

Last time I checked I thought we are not able to mount jammer pod on the wing. I thought at the time “it must be for FOV and symmetry that makes sense” but I found a picture with it on the wing. Maybe just a captive carry non-functional ferry flight?

EDIT: I found pictures of it on J-10 and JH-7 that are on off center pylon

Some other photos from recently. If you haven’t heard the air cooled KLJ-7A has been confirmed for Block III as reported by Jane’s. Which is funny because of the three KLJ-7A variants we know of none are air cooled and that was the whole reason for LKF-601 to compete, that it’s air cooling allowed retrofit on previous blocks.

One of the photos of shows the tail number on the base of the tail instead of the usual spot. Earlier photos of the same bort number show the tail code in the usual place. Very odd.

Also apparently all JF-17 have a FC1 code followed by their bort number without production year(makes sense because Chengdu doesn’t know when PAC will finish assembly). I find it interesting how common it must be then to be referred to as FC-1 in China and the fuselage production facility in Chengdu

wow, that refueling probe is... really in the way of your view on the right side.

Depends, at least it’s not right next to your HUD like a Dassault.

I think it might actually be useful for judging attack run angles:)

Yeah I guess it's not really in a place where you expect to have adversaries but still it makes the plane asymmetric without the option of retracting. :[

All the components required for retractable proble would probably add more weight and extra maintenance time. An F-16 type of refueling system would have been better but I don't really know how the internals of this jet are designed.

If we look at it, all light fighters have static fuel probe. The interesting part in JF-17 is that it can also be removed.

All the components required for retractable proble would probably add more weight and extra maintenance time. An F-16 type of refueling system would have been better but I don't really know how the internals of this jet are designed.

 

If we look at it, all light fighters have static fuel probe. The interesting part in JF-17 is that it can also be removed.

The Gripen has a retractable probe. (The first version the Jas 39A/B lacked a fuel probe but it was added with the Jas 39C/D in the mid 2000s)

And its only 250kg or so heavier so its still very much a Light fighter.

Lol can I remove it mid flight? That would be the best XD. I think the usaf style refuel kit is probably stupidly expensive compared to the basket system.

All the components required for retractable proble would probably add more weight and extra maintenance time. An F-16 type of refueling system would have been better but I don't really know how the internals of this jet are designed.

 

If we look at it, all light fighters have static fuel probe. The interesting part in JF-17 is that it can also be removed.

The removable probe is a trait originating from Dassault where operators usually have fewer probes then airplanes and switches them out as needed.

Also the tankers for Pakistan are 4 Il-78 bought as surplus from Ukraine. They use pods for refueling so I guess it’s possible if they bought a new pod system, but all their Mirages use probes as well, however F-16 is left in the dark. I believe their tankers were bought about ten years ago, so probes were not on their mind when buying F-16C. They originally wanted an Airbus that can switch types but it was too expensive https://quwa.org/2016/10/11/discussion-pakistans-f-16s-not-flight-refuelling-support/

I wonder how often those four tankers have to stay airborne to provide

Thanks for the info guys. This is good bit of information and explains the reasoning behind the military's decisions when developing or upgrading their arsenal.

I find it strange that you have time to impact inside the A2A target box, is that not strange? You cant see the actual bandit because of the clutter. So you need to look to the side of the HUD to see the dot instead of just have it inside the target box not cluttered by Time to impact number. Decluttering the HUD dont help the case and you still have time to impact inside target box.

Anyone figure out what uses the Pneumo system? Sometimes I use almost none of it and sometimes a minute or so after landing I use up almost all of it. I haven’t checked what it does with the emergency landing gear, but I assume that’s what the “Emergency” section is for and not the “Main.” I thought it was canopy becuase it makes a pnuemo sound but after a minute of moving my canopy nothing happened. I always think it’s the chute release or something but it doesn’t seem to do anything.

Also if anyone knows how to use the FCS test switches properly I would love to hear, I got it to work once but can’t reproduce

balanced fuel tank loadout limitation will be removed in next update

balanced fuel tank loadout limitation will be removed in next update

Looking forward to it. Really want to take 1 gb6sfw, 800 tank together

Whats the reason to remove ability to load BRM from inner station ? I honestly hate this update because I cant no longer load 2- 4 Sd-10 with 2 rack of BRM, well I can with assymetric load but its annoying to have constantly trimming for it.

Whats the reason to remove ability to load BRM from inner station ? I honestly hate this update because I cant no longer load 2- 4 Sd-10 with 2 rack of BRM, well I can with assymetric load but its annoying to have constantly trimming for it.

Smoke of the BRM rockets would get inside the engine, and thats a big no no, basically because that means that you're going to kill the engine

Wtf is wrong with this piece of shit engine? Does flying in cloud also kill it?

Wtf is wrong with this piece of shit engine? Does flying in cloud also kill it?

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Wtf is wrong with this piece of shit engine? Does flying in cloud also kill it?

Flanker has same limitations, only dropped ordinance near the engines. Even the Americans use only dropped ordinance close to the engines. Rafale and Eurofighter, all have conformal drop stations, not rails

Clouds are water and still have oxygen, but rocket exhaust is pretty oxygen depleted

But hornet and f15 stick amraams literally on the intakes unless I'm forgetting. It's how they carry 10 amraams and Jeff only manages 4.

AMRAAMS also fall away a fair bit before igniting, whereas rocket pods go straight forward.

But hornet and f15 stick amraams literally on the intakes unless I'm forgetting. It's how they carry 10 amraams and Jeff only manages 4.

They both eject/drop them before the AMRAAM ignites the engine.