iPadOS 11.4 (build 15F79) is an official Apple over-the-air update for the iPad Air (Cellular), released on 2018-05-29T17:13:12Z. The update package is 678.07 MB. This is a delta (partial) update that requires 11.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e6c972219b0bc4fa8d646ba8b5c00f9771068713.zip.