iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2018-04-24T17:07:50Z. The update package is 1.27 GB. This is a delta (partial) update that requires 10.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 6fccf32fdec6505ccb9fbf89a98f3ef835237cbc.zip.