iPadOS 9.0.1 (build 13A404) is an official Apple over-the-air update for the iPad Air 2 (WiFi), released on 2015-09-23T17:55:20Z. The update package is 1.07 GB. This is a delta (partial) update that requires 8.4.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 40f7735c0317c09f1e973f53b7681d2088953185.zip.