iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad Air (Cellular), released on 2018-04-24T17:05:16Z. The update package is 703.91 MB. This is a delta (partial) update that requires 11.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c970045621553e1e669d55fb170ac78ee9e446b2.zip.