SOURCE: IDRW NEWS NETWORK
As per official information sourced from Annual report of Aeronautical Development Agency (ADA) compiled together by idrw.org on India’s LCA Navy Mk2 Programme. The government of India has sanctioned the development of two LCA(Navy) Mk2 single seat Fighter prototypes (NP3 & NP4) under FSED Navy Phase-2.
The LCA (Navy) Mk2 is being designed primarily to provide air defence to the fleet onboard Carrier and meeting all the mission objectives set out by the Indian Navy. Significantly improved aircraft performance largely better than AF-Mk1 and integration of a full suite of weapons are capabilities inherent in the design.
The main contributors to improvement in LCA(Navy) Mk2 have been identified as higher thrust engine, an increased wing area, an area ruled and streamlined configuration, lighter landing gear and structure, and improved systems layout towards better safety and maintainability.
Flight control features to reduce approach speed even with an increase of around 2.5 tonnes of Carrier landing mass is a critical capability over LCA(Navy) Mk1.
System Requirements Review (SRR) with the participation of Indian Navy (IN) was carried out in detail with requirements capture and document prepared. Concept design of LCA(Navy) Mk2 has been completed and detail design phase initiated. A detailed Preliminary Design Document for LCA(Navy) Mk2 has been prepared and provided to IN. Carrier compatibility requirements of INS Vikramaditya and INS Vikrant have been captured and necessary features incorporated in the design.
Based on the requirement to consider wing folding to overcome the aft lift interference on INS Vikramaditya, a Technical Note was prepared and submitted to IN. The note details rationale behind Wing outboard shift for LCA(Navy) Mk2. Issues in not opting for a wing fold and also restrictions in carrier take-off mass if the wing is retained as in Navy, Mk1 was brought out.
A meeting chaired by RM on 27 April 2016 was conducted at MoD, Delhi with participation of IN to review LCA(Navy) Mk2 Programme. IN had brought out performance comparison of LCA(Navy) Mk2 with MiG-29K with respect to ASR/85.
In order to improve aircraft performance dedicated task teams have been constituted working towards mass and drag reduction. A comparative performance study of various naval combat aircraft was carried out with Airbus DS consultants and presented to stakeholders.
Design & Development Activities
(a) Aerodynamics & Configuration: Air Vehicle Configuration of LCA (Navy) Mk2 is a critical activity during the concept design phase. The major activities carried out are:
Ø NMG V0.6L has been baselined for detail design
Ø Improving performance in terms of low supersonic wave drag, acceptable CG limits for stability and control criteria for zero ballast design.
Ø Optimized LEVCON & Shelf Flaps to achieve approach speed reduction for carrier landing.
Ø LEVCON converted into an active surface permitting operations with higher instability to achieve improved agility and performance.
Ø Ventral Airbrakes for performance with low interference
Ø Air intake redesigned for the bigger GEF414-INS6 engine, with lip and cowl profiles and auxiliary doors optimised for superior performance at low speeds for improved carrier launch capability.
Ø 1:10 scale low-speed wind tunnel model fabricated at NAL and was tested in the HAL wind tunnel.
Ø Wind tunnel data correlation study with CFD simulation carried out and found to match very well. Based on the iterations carried out in configuration performance evaluation was also computed to arrive at an optimum solution.
The major activities were undertaken are:
Ø Installed performance estimation of new GE-F414-INS6 engine in LCA (Navy) Mk2 was carried out
Ø A comparative study on performance with contemporary Naval aircraft was carried out and shared with IN.
Ø Mission performance analysis for three IN profiles viz., Air Defence, Anti-ship and Ground strike was carried out and has been established to meet the IN requirements. Maximum capabilities in various IN defined missions to bring out margins available has also been evaluated.
(b) Airframe and Mechanical systems: Airframe: Preliminary Structure Layout with zero thickness model for NMG Version V0.06L for Front, Centre and Rear Fuselage incorporating 1020 mm longitudinal plug, 700 mm lateral plug. Concept studies of alternate Structural Layout for iterations on Inboards layout based on System the requirement was undertaken.
Main Landing Gear (MLG) interface with The airframe has been defined. This involved studies for MLG load path and definition of structural attachment to the fuselage. Structure layout for Nose Landing Gear (NLG) to suit the modified aircraft geometry is in progress. Arrestor hook structural integration concepts for different schemes were carried out.
Finite Element Model (FEM) of Airframe was prepared and detailed stress analysis for critical carrier landing load conditions evaluated. As a result of this analysis it is found that the bending moment loads for most critical 2 point landing case on the fuselage is around 30% lesser than in Navy Mk1. This was identified as a potential weight reduction opportunity and a detailed study undertaken.
Fuel tank layout to meet increased internal capacity and c.g management has been defined to carry out detail design. The Airframe team took active participation in workshops and webex discussions with Airbus DS team at ADA to converge on a feasible structural design solution.
Detail design of Airframe is in progress and CAD models/drawings are being created in the concurrent design environment.Landing gear & Arrestor Hook: The MLG configuration of LCA (Navy) Mk2 with an optimized structural interface made feasible by means of 350 mm additional space in the Y-direction of the aircraft has been finalised.
Following actions have been carried out:
Ø General Arrangement of Landing Gear System.
Ø Estimation of Landing Impact & Ground Manoeuvring Loads.
Ø Kinematics of Main Landing Gear & LG Doors
Ø Sizing of tyre and wheel size Kinematics of Nose Landing Gear & Doors has been updated to suit the new geometry V0.06L
Arrestor Hook design as a conformal the concept with Y-hook arrangement is being progressed by ARDC. Forcing function loads & Estimation of AHS Jack Loads has been carried out.
Engine: Higher thrust Engine GE-F414-INS6 is to be installed in LCA(Navy) Mk2. Updated Performance Cycle Deck(PCD) and CAD model of the Engine made available for design studies. ASMET and other qualification tests have been successfully completed by GE, USA and delivery of engines scheduled.
Avionics & Weapon systems
The Avionics architecture of LCA(Navy) Mk2 is to be adapted from the LCA-AF Mk2. Navy specific features are to be implemented based on interactions currently in progress with Indian Navy.
Feedback on AESA Radar and Communication interface has been received from IN. Network communications requirements have been sought from IN. Preliminary cockpit layout study for 19.8 Degree HUD has been carried out and feedback provided to CSIO, Chandigarh who are developing this LRU.
Studies for integrating Automatic Carrier Landing System (ACLS) have been initiated with the participation of IN. Interaction with NEC, Mumbai, to capture EMI/EMC interface requirements on Carrier carried out.
Airbus DS Design Consultancy
Quarterly workshops involving Aircraft design experts in major disciplines is in effect as part of Design Consultancy with M/s Airbus DS, Germany. The experts visit ADA for interactions with respective design teams. Based on the Design suggestions, design teams involving Aerodynamics, Structures and various groups have evolved Concept design of LCA (Navy) Mk2. ARDC, HAL as a principal partner is involved in these design activities.
The last 3 quarterly workshops (Total 11) planned as part of detail design phase has to be rescheduled and hence a requirement for PDC extension of this design consultancy up to Dec 2017 is needed.
Follow Up Activities planned for 2017
a) Detail design of LCA(Navy) Mk2
b) High-speed wind tunnel model fabrication and tests for force & moment and air intake
c) Development of Assembly Jigs
d) Raw material procurement
e) Fuel test rig
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