iPadOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPad Air (Cellular), released on 2015-10-21T17:15:54Z. The update package is 1.04 GB. This is a delta (partial) update that requires 8.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5a624ad18f25302bf4a77d79b07fb65bd6d98259.zip.