iPadOS 9.9.11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2018-04-24T17:07:42Z. The update package is 1.53 GB. This is a delta (partial) update that requires 8.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: ca65c495e669d92aa8cdb62840d9d7d598b530cf.zip.