(The following first appeared as the lead Comment in the 12 February 2013 issue of Flight International)
Iran's rollout of its Qaher-313 "stealth fighter" is little more than a poorly executed propaganda stunt for domestic consumption. It is immediately apparent from the many photos and video imagery of the purported "advanced aircraft" with a "very small radar cross-section" that this is not a serious development. At best, it is a subscale testbed, but in reality, it is probably just a mock-up.
Perhaps the most immediate giveaway is the minuscule size of the craft, which looks to be made from crudely painted fibreglass or Dacron fabric. There appears to be no room for avionics or fuel, let alone weapons. Moreover, it's doubtful that there is an engine installed, given the lack of a nozzle and the two tiny air inlets.
The other problem for Iran would be to find an engine small enough. Options seem limited to something like the General Electric J85, which Iran has previously reverse-engineered, but without a nozzle the heat would probably set this papier-mâché mock-up alight.
Additionally, the cockpit appears to be too small in relation to the pilot. The canopy is made of what appears to be polystyrene and visibility through the material can only be described as horrendous. But the cockpit instruments are among the only items in the Qaher-313 that might be real. The Iranians appear to be using instrumentation developed for the home-build aircraft market with hardware sourced from Dynon and Garmin.
There are also no visible access panels or weapons bays. Features such as access panels are found on every aircraft for routine maintenance, and in the case of a stealth aircraft, weapons bays are a must to maintain its low-observable signature while carrying armaments. But, as one engineer familiar with low-observables design astutely points out, while superficially resembling what one might imagine a stealth aircraft to look like, the Iranian machine has serious radar cross-section (RCS) problems.
Stealth aircraft design is much more than simply mastering the low-observable shapes. Advanced materials sciences need to be developed for the aircraft's skin and coatings. Advanced analytical tools are needed to shape the internal bulkheads and other structures. Moreover, one has to master the man-machine interfaces so a pilot can manage the aircraft's RCS spikes in flight. There is no evidence that might suggest Iran has anywhere near even a rudimentary grasp of those technologies.
The mystery is how Iran's leaders might assume that they could present such a transparent farce before the eyes of the world and expect anything other than merciless mockery.