What was different about their design considerations?
The F-18 has oversized stabilators and flight control surfaces for adequate flight control. Hawk airbrake might create a downward pitch, but the aircraft is designed to be very stable, since it’s a trainer.
And the Tejas has large elevons that can do the job of providing flight control as well. Point being, there is nothing that prevents the Tejas from using control surfaces to compensate for the pitch up moment applied by the airbrake; if the same can be done using elevators, then elevons can do it too.
Yeah..we know from reports (from a former IAF senior pilot) that even the F-16 Block 60 and Super Hornet didn't meet the IAF's STR requirements. Does that mean that if these were available for induction in the IAF, that the IAF would decline and reject them altogether? Very unlikely.
They were rejected for failing the technical evaluation, that included these very parameters. Your statement completely contradicts reality.
The F-16 was designed as a A2A fighter, and the bells and whistles added for A2G role ate away flight performance required for the A2A role.
But that doesn't take away the fact that even an F-16 Block 60 and the F/A-18E/F, one level more advanced than even the F-16 Block52 that is the IAF's primary threat, doesn't meet the IAF's specs for performance. But had there not been a Rafale/Typhoon on offer, the IAF would've jumped at the offer of inducting them.
It is mature and hasn't proven to be troublesome.
Then why can’t the FCS correct the uncommanded pitch created by the original airbrakes.
Because it requires work to be done on that. Why don't you go and read on the Typhoon's transonic pitch up issue and how it was resolved. It was no easy task. Your implication that had we gone for a mature Mirage-2000 derived FBW on the Tejas, this wouldn't have happened is simply not true. This issue would've had to be tackled by whichever FBW technology was used, be it quadruplex redundant or triplex redundant with analog backup as on the Mirage-2000.
but that isn't the reason that the IAF is keeping Tejas Mk1 orders to 40
Agreed, from what I have been told, the IAF considers the pitch effect a nuisance but definitely not a showstopper. It has no effect on the induction plans.
Told by whom? Are you in the know of the IAF's issues with the Tejas? Maybe you could tell us what else is keeping the IAF from ordering more Tejas' to replace the huge numbers of MiG-21s.
As for this issue, yes its not a show stopper, since as long as the pilot can bring the aircraft back to its original state, after any uncommanded motion, the issue is not going to be a show stopper. As put in the US Military Standard for piloted airplanes,
MIL-STD-1797A4 states: “The aircraft shall be…resistant to departure from controlled flight, post-stall gyrations and spins. Adequate warning of approach to departure shall be provided. The aircraft shall exhibit no uncommanded motion which cannot be arrested promptly by simple application of pilot control.”
In every other aspect, the Tejas' flying qualities are very highly rated by the IAF's test pilots who've flown it. When an IAF TP calls it as "comparable to amongst the best in the world in so far as flight controls in concerned"
, then that does speak volumes for the FBW and the general design of the aircraft. As another TP, Grp Cpt George Thomas said about it
"Its handling qualities are such that the pilot workload is low and the pilot can focus on sensors, weapons and combat and as regards basic flying, the aircraft can almost fly itself".
After all, most of these TP guys will be well versed with the Cooper-Harper handling qualities scale
on which "excellent" rating 1 means that the handling characteristics are highly desirable and pilot compensation is not a factor for desired performance and "good" rating means that there are negligible deficiencies in the handling characteristics and pilot compensation is not a factor for desired performance.
What does the second statement even mean? What is a simpler design process?
Thank you for asking this question. It means assessing all the available means to achieve an end, and choosing the simplest and least riskiest means of achieving that end.
Like having airbrakes closer to CoG than having it elsewhere and having FCS mitigate any side effects. FWIW, using MLG door is reverting back to simpler design philosophy. Now, I am sure that the designers would have had some valid reason for not doing so in the first time itself, like avionics in the dorsal or fuel tanks in the ventral or wings, however, a simpler approach would have given precedence to placement of airbrakes.
Thank you for at least accepting that there may have been other mitigating factors involved in the selection of the location for the airbrake. I'm not sure though that the airbrakes have precedence of placement over more important things like fuel tanks. Anyhow, on the Tejas Mk2, they have the opportunity to re-lay out some of the avionics and pipes and such a layout change may well be done for the airbrake.
Which BR member will volunteer his son or father or brother or husband to go to fight knowing fully well they cannot outturn the enemy in a sticky situation? I am sure your perspective of “IAF not supporting…” will do an Immelman turn when your own flesh and blood goes to a fight in a Mk1.
This is a stupid statement if there ever was one. The IAF is not going to induct Tejas Mk1s at a state below the FOC level. At which point, most niggling issues would've been licked and the platform itself would be capable of giving a sound whipping to any MiG-21 that it comes across. Yet, there are plenty of fathers, brothers and husbands who fly the MiG-21 today and are ready to go to war in it. The Mk1 will be far safer, far superior to it.