Because I think that the IAF has learnt it's lessons which is not to order anything from Russia which is not fully tested and bought by the Russian Air Force itself. That is why it's position on the SU-57 is that when the aircraft is deployed by the Russian Air Force in numbers, the IAF will be ready to re-visit the issue if needed. That lesson I think has been learnt during the development of the SU-30MKI from the basic SU-30K, the conversion of the Vikramaditya etc. So IMO the IAF will want to evaluate a fully developed version of the Zhuk AME AESA before it commits to buying it. Because invariably buying a product still in development in Russia means that some of the money paid on signing the contract will go towards product development. And the way the Russians operate, the end product will be developed partially with Indian money but India will have no input thereafter in it's future sales nor any rights towards it's IP. I think that India has learnt that lesson and that is why in the case of Brahmos it went for a JV. So to me at least as an outsider it looks like India is willing to buy fully developed products from Russia and if a product is still being developed, then it has to be in the form of a JV. For the SU-57 the Russians were not willing to agree to a JV so India dropped it. All of this is a long way of saying that India will not order the Zhuk AME AESA unless and until it is fully tested and can be evaluated on an operational Mig-35 which will not happen before 2022 at the earliest.