iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad 5 (Cellular), released on 2018-04-24T17:08:09Z. The update package is 714.48 MB. This is a delta (partial) update that requires 11.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 79bdc793b83313af1737954608e7c12e02a31186.zip.