g issue.
It is very interesting to see that one of the LCAs pulled 6gs in " clean configuration" last year somewhere in or before 25th of June, 2007 ! It's angle of attack too at that time was reaching 20 degrees however, with the addition of heavier engine, fuel tanks and a missile or two, its performance has deteriorated decreasing the AoA to 17 degrees and raising serious questions on LCAs ability to pull 6g in its current form.
Basically, LCA as of today stands somewhere between the basic trainer Mushak and medium trainer K8. Mushak can also pull 6+g and K8 can pull 7.3g. I stand corrected that LCA as of today is no better then a trainer.
http://www.pakistanidefence.com/DefenceProduction/PAC/Mushak_SuperMushak_Manufacturing.htm
FBW issue
From the 2004 ADA report: (Page 10)
In the final MC CSCI testing 60 errors were detected in about 100,000
lines of Ada source code and an analysis of the type of errors detected is as
follows:
Type of Errors Percentage of total errors
System Design 32
SRS 33
Design/Code/CSC Test 20
ICD (1553B Interface Control Document) 10
Others 5
http://www.bitsoftsystems.com/mydocs/Avionics%20Mission%20Computer%20Case%20Study.pdf
The only thing that comes to mind is that the LCA FBW is nothing but rubbish, and not even compared to a mechanical system which would not have this many errors since mechanism don’t used software !
This was then in 2004 and you say that it is still having software issue. Which means that the bugs still have not been fixed even after 4 years ?
Aerodynamics Issue
The plane is a two axis delta plane in the league of 1960s vintage mirage 3/5. All latest deltas have three axis. Even the upgraded Mirages of Israel (kfir) and South Afirca (cheetah) had three axis through the adds on of canards which mind you are all retired.
All latest deltas such as Grippen, J-10, Typhoon and Rafael have three axis. It is already obsolete by today's standards. Only thing worthy in LCA is the avionics provided if the integeration is successull in the end as there are still quite a few systems to be added and intergerated.
LCA has no elevator. What the Indians did they added the aerilon+elevator and came up with huge elevons and the rudder. Thus, only two control surfaces.
http://www.grc.nasa.gov/WWW/K-12/airplane/airplane.html
Just to give you a better idea :
The separate differential movement of the aerilons between left/right wings on a delta wing (LCA), elevator and aerilons can not be operated differentially opposite to each other on the same wing, the 2 segments will operate in the same direction on the same wing! Hence they are not a separate control surface as elevators (horizontal tail) + flaperons (wing) + rudder (vertical tail), but while the outboard trailing edge aerilons is augmented slightly with a higher angle (that is the reason they are segmented) against the inboard trailing edge elevators give superior roll rate on a delta wing A/C’s velocity vector as compared to the cropped tailed delta wing (F-16/JF-17) due to the extreme outboard trailing edge is fixed for wing tip missile pylon, also due to higher aspect ratio wings, hence high roll rates will damage wing structure.
Never the less! the JF-17 uses the differential movement of the opposite side of the horizontal tail to perform roll rates called “Tailerons” and collectively as “elevators” but the JF-17 also has an extra control surface on the wings “falperons” which operate differentially opposite to each other between left/right wings, giving it 2 surfaces which can operate differentially opposite to each other on each (left/right) wing and (left/right) horizontal tail and also opposite between 2 separate control surface horizontal tail and wing. Horizontal Tail + flaperons combined provide high STR higher AOA and much more lift. As oppose to one surface (wing) of the LCA “ with segmented elevons” add the rudder on both a/c’s to make it 3 on the JF-17 and 2 on LCA !!!
This is the reason most modern delta wings are introducing canards as a separate control surface to supplement the absent horizontal tail for extra lift. And the SU-35 has canards + horizontal/vertical tails + wings, making it a tri-plane configuration. Even a twin fin/rudder combination is a single control surface but will augment manoeuvrability much superior to a single fin/rudder stabiliser !
So if you read this with an open mind. You will understand that LCA's design is grossly obsolete by today's standards. It was a good design when envisioned but not anymore. It needs major and I mean really major redesigning to be able to hold to its own.
. By seeing the reports of summer trial and all seems like LCA is doing well.