The ASRAAM Block 6 seeker underperformed in testing and remedial work is expected to delay the missile’s in-service date until 2021. Life extension of Block 4 missiles beyond their current out-of-service date of 2022 will mitigate the risk of further delay. Block 6 missiles incorporate a UK-manufactured seeker and will progressively replace Block 4 as part of routine stockpile management.
I know we'll never know...but I wonder how long that Lifex will give the Block 4 Asraam. Be nice if we retained them in the stockpile as a war reserve. It's not as if they're not one of the worlds best WVR missiles still..