iPadOS 9.1 (build 13B5119e) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2015-09-23T17:55:07Z. The update package is 181.27 MB. This is a delta (partial) update that requires 9.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a1f377f076852abb87a16acf1861837ae1bf6971.zip.