iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad Air 2 (WiFi), released on 2018-04-24T17:07:33Z. The update package is 1.26 GB. This is a delta (partial) update that requires 10.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b256911406f57e648b7bb5635cd3f9f1a4b7f780.zip.