Is this whole programme faulty? I mean there’s something seriously wrong in the design I guess.
Interesting you should say that. One thing that has always stood out for me is the following.
Its got these tiny X-tail fins with a very low aspect ratio (literally 1-1.15 AR) - I fail to see how those fins could be doing anything for yaw stability at slow speeds. Also, think about the downwash/wake interference of those wings on the lower two fins of the x-tail. Maybe this is why they moved the wings down in later versions - thus minimising one problem and adding a brand new one for the FCS to keep the vehicle stable in the roll axis as well.
Not to say this is the problem - but I'm 100% sure the FCS is working over time keeping that thing straight in flight. Add to this weather, winds, complicated routes/trajectories with lots of sharp turns etc. and then you quickly start to see why the others have gone for dedicated vertical stabilisers.
- You see French Mdcn also with small tail fins but better AR (around 2) and still much bigger - also they have gone for a less challenging dedicated vertical stabiliser. Absolutely didn't want complicate yaw stability.
- Look at Storm Shadow/SCALP and you will see how much they have had to think about placement to maintain effectiveness from the tiny stabilisers - and they too use twin dedicated vertical stabilisers completely out of the wake of the wing - despite the fact it compromises stealth.
- Tomahawk doesn't bother with any of these challenges and just uses 3 simple HUGE stabilisers including a dedicated vertical. Maybe they learnt from older Tomahawks that had a low aspect ratio "Plus-tail" similar to Nirbhay X-tail. However, + instead of x means just you get 2 dedicated vertical stabilisers, only one of which is minimally affected with downwash/wake (downwash and wake affect horizontal fins more than vertical). That said, older Tomahawks also had a pretty tardy failure rate - up to 20%.
We've heard a lot about Nirbhay veering off-course. Initially I thought its the TRN/TERCOM playing up but then this is above sea. Maybe it's the above issue? The nav and autopilot could be configured correctly but maybe the FCS isn't able to translate into actual due to that tail? I'm 100% sure the people at ADE know stuff like this. I am also 200% sure that sometimes basic mistakes are made and persisted on projects run by competent people/organisations.