iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad Air 2 (WiFi), released on 2018-04-24T17:07:40Z. The update package is 608.46 MB. This is a delta (partial) update that requires 11.2.6 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 25a2516264a82fe8b0341805d45cccffd3cf3a69.zip.