Kartik wrote:That's where airframe rotation comes into the picture. Use those newer airframes more and rotate the oldest airframes with max hours on them into storage. There is no reason to believe that the Mirages cannot last 15-20 years as long as spares support is available.
Look, the avionics on the Mirage-2000I/TI are going to be good, adequate to tackle a bulk of the missions they will be tasked with. Engines can be used so long as spares are available and overhaul capabilities exist. But yes, I'm reasonably sure that when they say that the Mirages will be used for another 15-20 years, the IAF, HAL, Dassault and Snecma would have worked out a solution to keeping the M-53 engines well supported till thr fleet remains in service.
That'll be a hard thing to achieve with fresh airframes comprising only 20% of the fleet. Here's a back-of-the-envelope calculation of what it would imply.
1. The aircraft has a airframe fatigue life of 6,000 hrs, expended over 40 years at the rate of 150 hrs annually.
2. The 40 older units having flown for three decades will have about 1,500 hrs remaining or about 10 years @ 150 hrs/yr.
3. The 10 newer units having flown for just one decade will have 4,500 hrs remaining.
4. The fleet needs to generate a cumulative 7,500 hrs annually for pilot training. An average of 150 hrs/yr per aircraft (should ideally be more).
5. Assume the older units fly 100 hrs/yr to allow them to be operational for the next 15 years (i.e. upto 2030). That equates to 40 units flying 4,000 hrs annually.
6. That would require the remaining 10 units to fly a whopping 350 hrs per year to generate the balance 3,500 hrs required. That would also exhaust their airframe life in 13 years or by around 2028.
Even assuming each aircraft spends 1-2 years grounded while being upgraded, flogging it past 2030 doesn't appear to be doable. Not unless the airframe has gone through a SLEP to take it upto 8,000 hrs, something that hasn't been reported. Some reports explicitly state that its not a part of the upgrade contract.
The takeaway as I see it is two-fold. One, we desperately need more Tejas Mk1s with the rotation possibility affecting Mirage fleet's operation availability. For most missions its as good (if not better) than the Mirage. Two, the three Mirage squadrons may need to be folded into two squadrons to reduce the pilot-to-aircraft ratio in order to keep flight training at acceptable levels. Alternatively (if not preferably, the fleet needs to be supplemented with surplus French/Emirati/Qatari Mirages.