There is also a slight possibility that the nose pitot is a one off deal for a test airframe in case some things concerning aerodynamics, weight distribution and handling need to be tested on a so to say pre-serial airframe. Not sure how plausible is that, though.
J-15 carrier fighter thread
- Thread starter Jeff Head
- Start date
It is possible, but after some discussion with a colleague I think we had both concluded that the "plumbing" behind an aircraft's air data probes is something that needs to be redesigned if you want to remove the probe from the radome of an aircraft.
For existing airframes with radome probes, upgrading them with a new radar is probably not worth the extra additional cost of replumbing the radome and the overall forward nose/section of the aircraft. I think that is why upgraded J-11BG and upgraded F-16Vs retain their same radomes with the probes despite having new radars -- it's because the J-11B and F-16A/C/whatever variant already had a radome with a probe at the time.
OTOH, aircraft like J-16, J-11D and J-15D were significantly redesigned new build aircraft that were quite different from the original aircraft they were derived from (likely J-11BS airframe, J-11B airframe, and J-15 airframe respectively, IMO), so replumbing the radome would've probably been a small job to do in the scope of all the other changes they had to do.
For the suspected batch 3 J-15, the extent of structural modification from existing J-15s may be relatively light compared to the above examples, and it's possible that the only major upgrades are that of its avionics and possibly cockpit. For such a modification, it may not be judged to be worth the slight cost of replumbing and redesigning the air data probe configuration.
(Of course I think it would make sense for all batch 3 and onwards J-15s to be built to be CATOBAR compatible structurally as well, but that's a different matter).
Personally I think that the J-15 prototype may already have that nose pitot and is originally built with mechanical slotted array radar. They upgraded the prototype, and installed an AESA radar for testing and left the pitot. Generally, nose pitots does interfere with radar, so if the side probes have improved enough, the nose pitot should be removed with future designs.
Are you saying you think the J-15 in the pictures is one of the original J-15 prototypes?
The context of the pictures and what little we can see of that particular J-15 airframe in the picture (particularly the different degree of primer) is meant to suggest it's a new build batch 3 J-15 of some kind, I don't see how it may be thought of as one of the J-15 prototypes.
If everyone does agree on the assumption that the PLA won't be buying new build fighters without AESA in 2020, and if everyone does agree the picture depicts a new build batch 3 J-15, then imo there are really only two possible conclusions.
1: the J-15 depicted has an AESA and it retains its radome probe. Fine, there are examples of this in other aircraft, like F-16V and J-11BG. The fact that it retains a radome probe would suggest the new build J-15 has minimal structural changes from batch 1 and 2 J-15s and its improvements mostly lie in avionics.
2: the J-15 depicted happens to be a pre production or prototype batch 3 J-15 with substantially more structural changes than in option 1, meaning they need at least one test airframe with a radome air data probe for additional testing purposes, and that production airframes will remove the radome probe.
I think both options are somewhat plausible, but I think if we remove the association of "radome air data probe = not suited for AESA" (which was the purpose of that diagram I made) then I think option 1 would be the more null hypothesis.
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asif iqbal
Lieutenant General
This is one fighter ?
what does the Chinese text say does it say the production of batch 3 has started ?
if so is it STOBAR or CATOBAR capable ?
what does the Chinese text say does it say the production of batch 3 has started ?
if so is it STOBAR or CATOBAR capable ?
Yes I am thinking that one of the original prototypes have been recycled and upgraded for the AESA. Prototypes tend to be retained for further use as test beds.
I think the picture is one of the original J-15 prototypes upgraded with the AESA but it doesn't change the message that a new batch may be produced with or without the nose pitot.
Granted, putting the nose pitot back to the nose might be able to give a more precise reading of your air speed and that might be helpful for landing and takeoffs. With a side probe, the probe is partially affected by the difference of airspeed caused by the boundary layers of the air stream going around the aircraft, as gases and fluids tend to speed up as they travel near a surface or a duct.
Pitots and probes have nothing to do with radar. You can have an AESA and still have a nose pitot or without. There are only collateral reasons why the pitot is removed, and that it poses a potential interference on the radar. Remember, you got a metal object literally on the path of the radar's beams. It is possible that the pitot itself can be interfered by the radar, such as inserting EMF interference caused by the radar on the pitot's wiring. Or the microwaves can cause heat on the pitot that can affect its operation. Maybe with the increased power of the AESA, microwave cooking the pitot becomes a greater problem than previous radars.
The reason for having a pitot on the nose is that its the one place in the plane that enjoys a fresh air stream and is free from boundary layers wrapping around the air frame and which can cause a false air speed reading. This means this is probably the best and most accurate way to get air speed.
At least these are my theories to this matter.
One of the J-15s have the pitot tube, but the other doesn't. There is also a difference between the birds with and without the pitot tubes in the pattern of the green coloring, which I presume are areas of composite. It could be prototype vs. production model.