iPadOS 11.4 (build 15F5079a) is an official Apple over-the-air update for the iPad Air (WiFi), released on 2018-05-17T17:01:50Z. The update package is 222.74 MB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b39086aef71a7f922a5116d1cc4ac0212217ccb4.zip.