Tag Archives: AESA

Second China’s J-20 stealth fighter prototype's new radome: a sign of an installed AESA radar set?

New images published on the Chinese Internet (and in particular those available on the HobbyShangai.net site) showing China’s J-20 “Mighty Dragon” new prototype clearly show an interesting detail: the aircraft coded “2002” has a slightly different nose section than the first prototype, coded “2001”.

In particular, instead of being installed on the right hand side of the radome, the pitot static boom of the new prototype (whose first test flight is imminent) sticks out of the radome’s point.

Image credit: HobbyShangai.net

The pitot tube, used to determine the aircraft’s airspeed, is usually put on the nose of the plane or the wing: anywhere as long as it is always pointed in the direction of the flow. However, its position on series production planes does not always match the one on prototypes: the latter often carry simplified wirings or lack complete (radar) systems, hence they sport different radome shapes.

Although the change in the pitot position and the new radome can be related to many technical reasons, they could also be a sign of a different kind of radar fitted inside the new radome.

An active electronically scanned array (AESA) set?

The second prototype of the Chengdu J-20 fifth generation stealth fighter, coded 2002, could soon fly along the first one, coded 2001, that has been involved in the testing activities since Jan. 11, 2011.

Fighter generations comparison chart

The appearance of the new J-20 (unofficially dubbed “Black Eagle”) raised many questions about the Chinese stealth fighter. Some experts think it will be more capable than the F-22; others (and I’m among these ones) think that the real problem for the US with the J-20 is not with the aircraft’s performance, equipment and capabilities (even if the US legacy fighters were designed 20 years earlier than current Chinese or Russian fighters of the same “class”); the problem is that China will probably build thousands of them.

Anyway, comparing the US and Chinese fighters, everybody referred to “fifth generation planes” bringing once again the concept of “fighter generation” under the spotlight.

Generations are a common way to classify jet fighters. Often, generations have been “assigned” to fighters in accordance with the timeframes encompassing the peak period of service entry for such aircraft.

The best definition I’ve found so far of fighter generations is the one contained in an article published in 2009 by Air Force Magazine, that proposes a generations breakdown based on capabilities:

Generation 1: Jet propulsion

Generation 2: Swept wings; range-only radar; infrared missiles

Generation 3: Supersonic speed; pulse radar; able to shoot at targets beyond visual range.

Generation 4: Pulse-doppler radar; high maneuverability; look-down, shoot-down missiles.

Generation 4+: High agility; sensor fusion; reduced signatures.

Generation 4++: Active electronically scanned arrays; continued reduced signatures or some “active” (waveform canceling) stealth; some supercruise.

Generation 5: All-aspect stealth with internal weapons, extreme agility, full-sensor fusion, integrated avionics, some or full supercruise.

Potential Generation 6: extreme stealth; efficient in all flight regimes (subsonic to multi-Mach); possible “morphing” capability; smart skins; highly networked; extremely sensitive sensors; optionally manned; directed energy weapons.

In order to give the readers a rough idea of the type of aircraft belonging to each generation based on the above breakdown I’ve prepared the following table with the help of Tom Cooper / ACIG.org and Ugo Crisponi / Aviatiographic.com, who provided the profiles. It’s not meant to show all the aircraft theoretically belonging to a generation and includes only the profiles available at the time of writing…

As I’ve already said on Twitter, what such a table should let you understand at a glance is that capabilities and appearance are inversely proportional: former generations aircraft look much better than more modern fighters…..