Actually the answer is simple to add any external add-on it not just plug and fly format they have to do CFD calculation and other simulation for aerodynamic characteristics change to make sure that it won't make any un nessery vibration or it may lead to resonance effect which may effect flight controls inputs ( see f22 crash video ) then ODl and rwr already present these are LRU it won't affects the bird's flying characteristics
So hal need OEM certification to get after sale's warranty if not anything happens to bird they won't take responsibility ( remember when machine computer of mki caused ejection of pilots OEM taken responsible)
Seriously ?
Read again what I wrote previously
When the aerodynamic studies will be done inhouse , then the design will be done inhouse , then integration will be done inhouse and testing will be done inhouse.
.
Even installing RWRs need aerodynamic stimulations , who said they are simply LRUs , only the associated processors are LRUs. Where are the receivers placed, inside ? or outside the aircraft ?
And who said ODL is simply LRUs , where will the associated antennas be placed, internal ? Or external ?
Anything external to the aircraft even if of minute dimensions need aerodynamic stimulation and certification.
And also what OEM certification in the case of Su30mki ?
Who is building the aircraft from scratch ?
Sukhoi ?
Or
HAL ?
And therefore who provides the warranty ?
The manufacturer who got the ToT to build the same ?
Or
The designer ( cum manufacturer ) who gave the licence to another manufacturer to build the same ?
OEM gives warrenty to products build by it not those built under license by another company.
My last post regarding this.