Thanks for posting …. but one thing makes me curious … :

If You compare the front fuselage of the earlier prototypes and the no. 04 than You can notice that the squared sides were changed back to more sounded sides … Any idea, WHY ????

With stealth in mind (even if the FC-1 is surely not stealthy) I think, the angled sides were less visible than these rounded ???

Cheers, Deino :confused:

Mainly aerodynamics, Deino.

To begin with diverter plates are used to separate the “boundary layer” of air that comes off the body of the aircraft in front of the inlet. This is slowed and chaotic air that can choked an engine.

The angled sides just in front of the inlets in the earlier FC-1 version are to create a consistent gap between the body of the aircraft and the diverter plates therefore ensuring a separation of the boundary layer.

The new 04 prototype uses a diverterless bump and the principle depends on the shape of the bump to deflect the slowed air coming off the body of the aircraft in the boundary layer.

The design no longer depend on a gap but on the angle of the bump and the angle along the body of the plane in front of the inlets that air rush in.

The mouths of the inlets are also now scooped (angled forward, instead of being perpendicular) as part of the DSI principle of dealing with the boundary layer.

Giant detailed profile of FC-1 prototype 04!

From Pakistani television. It seems that the 04 prototype is now painted a silver or whitish blue color. Picture of the PAF Air Marshal.

http://www.paktribune.com/news/index.php?id=143355

Chief of the Air Staff, Air Chief Marshal Tanvir Mahmood Ahmed flashes victory signs sitting in the cockpit of Prototype-4 of JF-17 aircraft.

’4th Prototype JF-17 ’Thunder’ aircraft successfully completed inaugural flight’

Thursday May 11, 2006 (0152 PST)

ISLAMABAD: The fourth Prototype (PT-4) of JF-17 ’Thunder’ aircraft, jointly produced by China and Pakistan, on Wednesday successfully completed its inaugural flight in Chengdu, China.

Chief of the Air Staff Air Chief Marshal Tanvir Mahmood Ahmed was the chief guest on the occasion.

Other members of the CAS high profile delegation included Air Marshal Rahat Hussain Khan CPD JF-17 and various high ranking officials of PAF and the MOD. The Chinese side was represented by Vice ministers of CONSTING, Presidents of Aviation Industries Corporation-1 (AVIC-1), CATIC, Chengdu Aircraft Design Institute (CADI), Chengdu Aircraft manufacturing Center (CAC) and other high ranking officials.

Speaking at the occasion, the Air Chief congratulated all members of Chengdu Aircraft Design Institute, Chengdu Aircraft Corporation and PAF contingent deployed at milestones achieved for the JF-17 programme so far. He termed that the success of the joint programme as one of the most successful programmes in the recent aviation history.

More

Get ready for pictures of FC-1 Prototype 04 coming up in the next two days!

http://en.chinabroadcast.cn/811/2006/05/08/53@86044.htm

Pakistan Air Chief Visiting China
2006-05-08 20:29:04 Xinhua

Pakistan Air Force (PAF) Chief left for China on a five-day official visit to see the first operational flight of Proto type 4 of JF-17 Thunder aircraft, a co-product of Pakistan and China, a PAF statement said Monday.

The JF-17 Thunder, equipped with advanced electronics and weapon systems, was a joint venture between Pakistan and China, the statement said.

Air Marshal Tanvir Mahmood Ahmed would witness the first operational flight of JF-17 Thunder aircraft in Chengdu, capital of China’s Sichuan province, it said.

Soon after the flight, formal production of the new aircraft would start marking a major leap forward in bilateral cooperation of the two countries in the defense sector, the statement said.