China is buying advanced jet trainers (28 Su-27UBKs) from Russia, eight of which are being delivered immediately. These trainers will allow China to train more pilots for use in the latest warplanes. China also  will buy four Russian A-50 AWACS radar aircraft, and pay for the Russians to update the electronics on the A-50 (which now uses 20 year old technology and is much less capable than the US AWACS.) The Chinese want an AWACS so that they can  launch an effective air offensive against Taiwan.