If this is achieved this would make it the fastest development, and dev/ops testing 5th gen program in the world, taking roughly 60% the time compared to everyone else. A more realistic timeframe is 10-12 years for EMD and dev/ops testing once the tech demonstrators transition into a production representative prototype with full mission systems and capability .If the first AMCA squadron is operational by 2035, this would be a pretty well run program assuming that the first demonstrator flies by 2023 or so.
The other 5 gen programs were developed at a time when engines produced less power, AeSA radars were unheard of, obogs was completely new, 4 gen aircraft had all metal bodies etc
Tejas will have many of the technologies which had been developed only for 5th gen aircraft. So our development time will be much shorter if Tejas and MWF achieve a high rate of production.
If you read my post again, you will realize that I was not referring to technology development at all. The time frame I referred to is for EMD, developmental and operational testing i.e. the post Technology Maturation and Risk Reduction time frame (under the Orange line in the graphic above). For example, ATF entered its EMD phase in 1991, flew the first EMD configuration aircraft in 1997 which started the developmental test program. Configuration development, maturation of technology in support of things like AESA radar, setting up the GaAs industrial base etc. happened prior to start of EMD as is mandated by law (or else no Milestone B in the US). First LRIP batch was ordered in 2001, and was delivered in 2003 and went straight into Operational testing (Operational testers refused to use non LRIP aircraft for OT certification) soon after that. IOC for the initial block was granted in 2005 or more than 14.5 years after the program entered its EMD phase, 8 years after an EMD configure aircraft first flew, or more than 4 years after first Low Rate Initial Production batch was sanctioned. The EMD program followed an extensive TMRR phase where technologies you mentioned were de-risked and matured so that they could be integrated. In total, the developmental test program for the F-22 involved 9 aircraft, each specially fitted and tasked with testing and validating things like flying qualities, integrated avionics, low-observable measurements, and weapons integration and deployment. Together, these 9 aircraft flew about 2500 sorties and racked up nearly 5000 hours of flying over a 6-7 year period.
The flying 757 test bed too racked up some serious flight time as well in support of all the avionics testing and sensors. The team that worked on the aircraft program had just come off of a large peak in Low Observable funding having delivered on a couple of programs, and competed on a few others. They were not novices when it came to dealing with LO/VLO requirements, static or dynamic RCS testing, Internal Weapons Bay development, integration or testing as you may be implying just by given the timeframes involved. Still some new technology needed to be developed for dynamic RCS and IR signature testing given the F-22 was supersonic and flew at much higher altitudes compared to LO/VLO aircraft of the past. Things like giant multi-spectral IR signature measurement pods needed to be developed and strapped on F-15's so that the IR signature at various bands could be measured while the aircraft was supercruising. None of the existing stuff was capable of doing this in an A2A configuration. Similarly, multi-band Radar equipped aircraft are seen chasing US stealth aircraft for dynamic RCS measurement and validation and these were extensively used in support of flight test activities as well. All this take time even when your entire test range community and industrial base had delivered on the F-117 and B-2 programs (and numerous other smaller demonstrators)!
The F-35 program entered SDD in 2001, and the first SDD configuration example flew in 2006 which kick started the developmental test program which lasted > 9,000 flights spanning more than 17,000 hours and covering nearly 67,000 test points in support of developmental testing. IOT&E on the F-35 is nearly done (live tests are almost all done with M&S activities left) but the road from first production (LRIP) aircraft to IOC was about a decade as well. The F-35 team had the benefit of delivering the only other operational fifth generation fighter program in service at the time so in many ways this was a continuation and progression of the work they were doing since the late 1980s.
The Sukhoi Design bureau was selected as the lead developer of the PAK-FA in April of 2002, and from what we hear, the first serial production batch was sanctioned a little while ago and first serially produced Su-57 is expected to be delivered by late 2019, or about 17 years later.
Bottom line is everything from developing key enabling technologies (least of which revolves around Low Observables and integrated mission systems) to integrating them into LO airframes, test beds to running developmental and operational test programs that can take multiple of 4th generation fighter program test-points is HARD and has historically taken the rest of the world a pretty long time. No matter the time-frame, there will always be "FIRSTS" for the developers, and FIRSTS for the operators and testers. This is hard stuff and takes time to develop, master, test, discover, correct, test again, validate, certify and operationalize. None of the earlier examples that I cited were teams that wanted to do this slow, take it easy, or delay for the sake of delaying. And for none of those teams involves in the EMD or SDD phases was AESA radars "unheard off", or the only reference point was 4th generation aircraft. Some had already delivered and even opertionalized Low Observable, IWB carrying strike aircraft prior to begining their EMD work on the ATF.
Here is a reasonable time-line for the AMCA if funding is approved swiftly, pace of funding is never an issue and glitches and pitfalls are minimal -
Tech Demonstrator(s) First Flight and Flight Testing - 2022-2024
Final Configuration Production Quality Aircraft Deliveries - 2026-2027
Developmental and Operational Testing - 2025 - 2035
Initial Operational Capability - Post 2035
If the MOD/IAF/AdA can get a Flying Test Bed with all the planned sensors up in the air in the next couple of years, it would be great as it will allow them to get ahead of some of these things but for all intents and purposes, the AMCA in squadron service is a post 2035 proposition though I will be more than happy to be proven wrong.
If HAL can deliver an operational MWF squadron by 2026, and an operational AMCA squadron by 2036 they would have hit it out of the park IMHO!
But from my observation standpoint (having followed 5th gen fighter programs for over two decades) there are two universal themes that keep recurring - 1) That 5th gen aircraft, integrated mission systems, performance, IWB and LO shaping, and materials is some SERIOUS hard work and the complexity and technical hurdles have consumed a lot of time of everyone that has taken on the challenge and 2) The operator community and the civilian administrators put in charge of them have almost universally underestimated the magnitude of the challenge as has been reflected in their initial estimates for both cost and schedule. Again all well intentioned folks wanting to get everything right and on time. This stuff is just hard because you are inventing in many cases and iterating on the fly.