1. What does the author mean when he states that ground support is needed for Tejas flight?
The aircraft carries a lot of telemetry equipment which is directly relayed to ground stations. A lot of information about the flying characteristics of the aircraft are relayed to people on the ground who monitor every single detail of the aircraft. Performance of the engines, moving surfaces etc. Meaning the pilot simply does what the ground crew tells him to do. Roll at 200 deg/sec, go vertical at 300 Knots, fly to this altitude etc. With every maneuver they check if the FBW is performing the way it is supposed to. They check if the deflection of the moving surface is enough for the maneuver it is performing, they check if the engine is consuming the right amount of fuel for a particular maneuver etc. If an anomaly is detected, they bring the plane back to the ground and they make the necessary changes.
Even during air shows, some or the other testing procedure goes on. For eg: When the PAKFA's engines swallowed too much fuel, the data they received was very invaluable for the ground crew.
All of this is practically impossible for the pilot alone to handle. Nor does he have the equipment required to perform such diagnostic checks.
In an operational aircraft, all the telemetry devices are gone and the aircraft flies without its flying characteristics being monitored. When the aircraft comes back to the ground, they only perform routine checks for wear and tear, leakages etc.
2. How good is the Tejas radar as compared to the ones in Mig 29 UPG, Kopyo in Bison and Zhuk in MKI?
Zhuk-ME (624mm array) and the Tejas MMR (650m) are of similar class. Mig-21's Kopyo-M (500mm) radar is inferior and has a smaller array.
MKI does not have the Zhuk, it has Bars. Bars (960mm) is a next generation radar, ESA array. It has over 1600 T/R modules. Zhuk AESA will be our best flying radar.
3. Could you elaborate more on landing carriage being overweight issue. I have not yet seen this issue discussed
anywhere in detail.
Nothing much to say because information is not easily available. Landing carriage is overweight and it is part and parcel of out development program because of our lack of experience. The AF version will be fixed first followed by the navy version. In the navy version, they had to strengthen the tail end along with adding an arrestor hook. That has added 500Kg to the aircraft. Landing carriage had to be strengthened too, primarily the nose wheel and the hydraulics. So that has added to the weight. LEVCONS too add to the weight. Even with practical increases in weight, there has been unnecessary weight increases which EADS is helping us with. Because of the small size of the aircraft, making changes is extremely difficult and hence takes longer.
On LCA Mk2 the AF is quite happy with a 98KN level engine, but Navy is most probably thinking about importing the F-414EPE because it will be ~1000Kg heavier than AF version with all the flaws fixed.