PLAAF in Tibet
THE APPEARANCE of a photo of a J-20 stealth fifth generation fighter of the Peoples’ Liberation Army Air Force ( PLAAF) at Daocheng Yading airfield (14,527 feet Above Mean Sea Level) in Tibet set in motion a flurry of articles and television news reports in India. The point being made was that China had ‘leaked’ this photo on purpose just before Prime Minister Narendra Modi’s trip to Vietnam (where he was supposed to announce the sale of BrahMos supersonic missile) and just after the Indian announcement that BrahMos missiles would be stationed in the North East; the aim, as per the media, was that China was ‘signaling’ to dissuade India from taking steps that it saw as prejudicial to its security interests. While the reasons behind the ‘leak’ of the photograph would be analysed later in this article, this piece looks at the new developments taking place in capability enhancement of aviation assets (fighter, airlift and heli lift assets) of PLAAF to enable them operate from high altitude airfields in Tibet; and what this entails for Indian air power.
The question arises why this special analysis for high altitude operations? A look at the map would show that the India-China border, most of which is disputed, runs for around 4,000 kilometers. If this had all been of average elevation that prevails elsewhere on the Chinese borders then the task of their aeronautical engineers would have been simple to produe aviation assets with good payload capability. But, the Tibetan plateau is the ‘roof of the world.’ The air density being generally 25 to 30 per cent less in the area compared to sea level, aircraft performance is severely curtailed. To get an idea of the curtailment, consider the fact that in summers an IL-76 sometimes carries NO passengers in a take-off from Leh while a Cheetah helicopter operating at some of the highest helipads on the Siachen Glacier carries just 25 kg --one jerry can of fuel – in its first sortie! So, the low density of air over all Tibetan airfields will exact a heavy performance penalty. How are the Chinese planning for this in their modernisation plan with new indigenous aviation inductions that they would expect in the Tibet area?
TRANSPORT AIRCRAFT FLEET
The present workhorse of PLAAF transport fleet is the Russia-sourced IL-76, whose ‘hot and high’ performance is not good in the Tibet plateau, as brought out earlier. The focus of attention in the transport aircraft fleet of PLAAF has now shifted to the indigenous heavy airlifter Y-20 that entered service in June this year. The programme began in 2007 and the design that emerged was a cross between the Russian IL-76 and the American C-17 Globemaster - - the fuselage is broader than an IL76 but the aircraft is shorter in length as compared to a C-17. The aircraft is entering service with Russian D-30KP2 aero engines, a power plant that flies on the IL-76 too. Thus, presently, the Y 20 has a claimed payload capability of around 55 tonnes, which is more than an IL-76 (40 tonnes) but less than the 70 tonnes carried by the C 17. With the present capability, the Y-20 will find it difficult to ferry the ZTZ99 main battle tank of PLA but on fitment of the indigenous under-trial WS-20 engines the payload capability would go up to 66 tonnes. With the rate of decrease in engine power due increase in altitude being the major element of drop in aircraft performance, the power loss in the modern WS-20 engine is expected to be at a lower rate since the engine would be FADEC controlled and would be a modern turbofan; the D-30KP2 is an earlier generation turbojet engine. The WS-20 has finished airborne trials last year on an IL 76 test bed, but its certification has not yet been announced. Considering that after certification, some finite time would be required for productionising the final variant, one can surmise that a Y-20 with indigenous engines is still a few years away from operational service.
The Y-20 with indigenous engines would be the ideal platform to be used as a base for an AWACS platform and for being an aerial refueller too. Its operation from most Tibetan airfields in these two force multiplier roles would be a peacetime exercise only, due their relative proximity to Indian airfields; however, the additional payload capability would be a big boon to their performance levels.
ROTARY WING FLEET
Comparatively speaking, altitude has a greater deleterious effect on helicopter performance than on a fixed wing platform. Of the present helicopters being used in Tibet by China, the Sikorsky S-70C is
PLAAF’s J-10s taking off from Shigatse air base in Tibet
J-20 in Tibet??