iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad 5 (WiFi), released on 2018-04-24T17:08:03Z. The update package is 621.15 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: be62623ecf2ab2983c31703235ad013f566f1d70.zip.