Indranil wrote:Okay, with these papers in the open I can talk more openly.
1. They have been working on improving the CnBeta characteristics for a while now. The hull of the LSPs are not particularly uniform and this leads to unstability at higher AoA. All the improvements in LSP 7/8 that you see the smoothening of the air intake for the environment control (at the base of the fin) etc. are related to this. With these improvements they have been able to test fly till 26 degree AoA. Consequently, the in service SPs are limited to 24 degree AoA. They are trying to push it further to 28 degree AoA, enabling them to clear the in service aircraft to 26 degree AoA. At 26 degree AoA, the aircraft will have a minimum speed in tha 185-190 kmph range. This is basically the same as the Gripen. If they can clear Mk1A/Mk2 to 28 degrees, you are looking at something special.
Could you get confirmation on the strakes and the nose chine for the Mk1A and Mk2? Actually, those design improvements seem small enough to be able to test on the Mk1 in service and introduce it to all SPs.
28 degrees AoA for service jets would mean 2 degrees less than the Rafale, and 2 more than the Gripen C/D/E. Now that would be something!
2. Kartik, that LCA-Navy pic is from AI-15. I have been asking folks to show me the pics from AI-17. The Naval LCA will look different. They have retained the wing, but pushed the wing joins outside by about 300 mm on both sides. This allows them to accommodate the straight MLG right next to the air intakes (it retracts kind of to the side and above it). The body plug is 1 meter long instead of the 0.5 mtr of the AF Mk2. Consequently, the nose has developed a chin, very similar to that of the Rafale. They will change the airbrakes too, because the current airbrakes are not suitable for carrier landing. They really considering on making the LEvcon active as well in stead of better maneuverability.
Did they have a new model of the LCA Navy Mk2 at Aero India 2017? Whatever little I saw through videos indicated that it was the same model displayed at Aero India 2015. And way back after Aero India 2013, I had posted about my conversation with Cmde. Sukesh Nagaraj of ADA
, who had mentioned that the fuselage would be widened, thus pushing out the wing joins- the wing span was not being increased directly though. The part about the 1m fuselage length increase for the LCA Navy Mk2 was new to me, and was confirmed by ADA Director Cmde. Balaji at this AI-2017. From my post on BRF back then-
- The widening of the fuselage will push out the wings a bit, thus increasing wing span. Otherwise no increase in wing span as such. It doesn’t need it, since the wing area is massive already
- On the N-LCA Mk2 they will change the position of the landing gear and bring it more towards the wing/fuselage joint. The landing gear will then retract into a fairing for that. That will also free up space in the fuselage for additional fuel
I really badly want to see the final designs of the LCA Navy Mk2 and the LCA AF Mk2! I wish someone could pull a scoop on those, since ADA seems unlikely to publicize these.
3. Kartik, you are a little late on the canopy optimizations. Me and Jay had a detailed discussion on this before. But you are really the first to notice that the AF-Mk2 does show the new canopy shape!
I seem to have missed those discussions on the canopy optimization- any link to that discussion?
This was the first time I saw it but the gains in drag reduction and improvement in transonic acceleration seem big enough to port these changes to the Mk1A variant. But that doesn't seem to be happening, or at least we haven't yet heard of that.
ADA hasn't released 3 view CAD renderings of the LCA AF Mk2 for whatever reason. There are more images of the AMCA floating around than the in-detail design LCA AF Mk2 for some reason. Would be great if someone like Ananth Krishnan could write a detailed article on the LCA AF Mk2 with good images showing the changes. Not sure why ADA is being so coy about that.
4. I would love to see the chaff dispensers housed in a better way, than the semi-protruding manner currently employed. It looks like a hack and must be adding to the drag significantly. Another eye sore for me is the current air intake at the root of the fin. They can definitely do better.
5. Otherwise, things are really shaping up well. I kind of wished though that they could consolidate the AF and IN requirements into one aircraft. IMHO AF would love the LCA Navy Mk2 with same shape, but lighter aerostructures. It will reduce design and testing times significantly!
The air intake at the root of the fin is already an improvement on the earlier design. From the renderings we've seen, it seems like they're not changing that. As for the AF and Navy having the same primary design, I'd agree, except maybe for the landing gear. Even a lighter and smaller MLG located in the same position as that for the LCA Navy Mk2 would probably be heavier than the fuselage housed MLG currently, with a bigger extension of the oleos. On the flip side, that might free up some space in the fuselage for fuel tanks, ala Gripen NG/E.