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 1.13 GB. This is a delta (partial) update that requires 8.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 79b1d3d6ba507dbdcde3204477e2a71a45590d7b.zip.