iPadOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2015-10-21T17:15:59Z. The update package is 263.97 MB. This is a delta (partial) update that requires 9.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a027f40399882e3fbdd1f7a046c6cef3595c6967.zip.