^^ The weapon in question SDBII is not slated to be cleared for the F-35 before 2021 at the earliest (its a block 4 weapon) yet the F-35B would begin to roll out of the factory with the changes around 2019.
This quote form the JPO spokesperson:
The JPO is targeting to have the F-35B weapons bay changes incorporated into the post-systems development and demonstration airplanes delivered in the 2019, 2020 time frame and beyond, DellaVedova said in a Feb. 25 phone interview with ITAF. "There are considerations for small bay changes to support the rest of the Block 4 weapons suite. Rather than make multiple small changes, we're planning to do one modification that will address all Block 4 requirements," he said
The SDBII is not a part of the SDD effort, and given that the SDD phase itself has seen a 5 year delay (Total minus 2) it would have been an absolutely retarded decision to begin to seek design changes for a non-SDD configuration in SDD and delaying the program further.
In this situation you can do one of three things -
- Re-design the weapon
- Re-configure the bay
- Do both
*The AMRAAM re-design was a perfect example in the case of the F-22A raptor. I guess that was also due to a common requirement
. Did they not know the dimensions of the AMRAAM?
On a more serious note - the AMRAAM was clipped to be able to carry the load of 6 in the bay, it was a conscious decision taken at the time of the F-22 design freeze because they went back and ran the numbers and the certification cost and the design changes would not significantly impact the AMRAAM program. The weapon was ready by the time the F-22A needed it. The Meteor is also getting a clip for the F-35, much like the AMRAAM got a clip for the F-22.
* If the bay can be re-designed in a simpler, cost effective manner then this solution ensures compatibility with common weapons and does away with the need to re-test the weapon that can be expensive and time-consuming. This is done in cases where it is simple to do so without the need to go out and re-test separations from the bay for all of its cleared weapons. It appears that the JPO has calculated that any minor changes to the Bay on the F-35B would not involve re-testing therefore this was the option chosen as is evident from their clarification that Lockheed would be awarded a contract later this year for these changes.
I am fairly certain that a Mid-Life-Update on the F-22 would do away with the launch system for the Aim-9 as I expect a full LOAL ejector type sidewinder to be the norm around the second half of the 2020's. That would be a change incorporated to the F-22 Side bays and they would be made simpler, and lighter.
New capability is always being looked at. Some have questioned as to why the UAI interface was not a SDD requirement because it just "makes sense". Same applies for other weapons such as the SDB II that go live before SDD completion date. The problem is that these programs themselves (UAI and SDBII) were very immature during F-35's development and putting them into the SDD would have meant huge external pressure on the program's success from a time-line perspective. Sure the SDBII has gone relatively smoothly, and so has the UAI (largely) yet that was not a guarantee when the F-35 was being conceptualized or baselined. Its wiser to wait for 2-3 years post SDD and not enslave the program development to untested and risky development programs. There are likely to be other capabilities planned for the F-35 in the future that would require baseline changes to accommodate.
There are some "serious"
propulsion advancements being contemplated for the F-35, even without moving to all new Adaptive Engines of the future: Croswell said Pratt had also developed plans to upgrade the F135 engine in two separate phases.
If the Pentagon accepts and funds the plans, the first upgrades would begin in 2017 or 2018 and reduce the fuel burn of the engine by 5 to 7 percent, Croswell said. The next upgrades would begin around 2022, cutting fuel burn by 15 to 20 percent.
The upgrades drew on engine research work funded by the Air Force in recent years, he said. The service included funding for more work on a next-generation engine in its 2016 budget plan.
The reason why all this is coming out (SDBII integration steps, Engine enhancements etc etc) is because the partners started sitting down last year to begin to firm up requirements for the Block 4 configuration that is due by 2021-2022 (Block 4i and 4F). Almost all of the capability demanded in that block have been frozen yet some things are still left for negotiations. This block gets SDBII, JSM internal and external integration, Turkisk SOM internal integration among other capability (Enhancements in the capability in the EODAS and EOTS and EODAS fusion). Last year it was revealed that the USAF is looking at a Pacific focused integration plan for block 4F and beyond and all these enhancements coming out of the OEM's are because they see an opportunity to latch onto those investments.
Last year the Naval Air Systems Command issued a Presolicitation
for block 4 activity -The F-35 Joint Strike Fighter (JSF) Program Office intends to negotiate and award multiple contract actions to Lockheed Martin Aeronautics, Fort Worth, TX for the F-35 Block 4 Follow on Development (FoD) Program. The contract actions will include assessments and evaluations of the Air System's ability to meet future operational requirements; systems engineering and design; procurement and support for prototype construction; upgrade of existing hardware and test assets; comprehensive test and evaluation to demonstrate the development and performance of the Block 4 requirements; and acquisition of technical, administrative, and financial data.
As per the original requirement SDD phase ends with the full certification of Block 3F and with it the official developmental program concludes. Block 4 i, Block 4F and a future block 5 are upgrades that although beginning now are not included in the SDD phase (contracts are over and above SDD). Just like the F-16, the F-35 would be constantly upgraded over time, the 2020's would see two major upgrades in block IV and V.
Here is a tentative/notional Block 4/5 and block 6/7 plan.