iPadOS 11.1.1 (build 15B150) is an official Apple over-the-air update for the iPad Air (WiFi), released on 2017-11-09T18:03:42Z. The update package is 1016.38 MB. This is a delta (partial) update that requires 10.3.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f14594a56829a1ff5ab088e78bb63272a7e78b27.zip.