We highly recommend that you download Adobe PDF viewer (or similar) as an app on your iPad. The guide itself is nearly 500 pages and requires a decent amount of memory. Typically web browsers (such as Google Chrome, and Safari) are not designed to show eBooks that size and this is why you're seeing this crash.
So if you have downloaded the guide successfully to your iPad, please use a PDF viewer.
Alternatively, if you're having issues actually downloading it to your iPad directly, please try this.
1 - On your PC/Desktop/Laptop, download the guide from your account (you have unlimited downloads).
2 - If you use something such as Google Drive, OneDrive, iCloud, etc - upload the guide there.
3 - On your iPad, install/load the app you used to upload the guide to in step 2. You will then be able to download it/open it from that application (or the aforementioned PDF viewer).
You can also add the guide to your Microsoft Flight Simulator install if you have it on PC. You can copy the folder 'sofly-pdf-guide' to your Community folder and then have access to the guide from within the simulator (in the tool bar menu).
Please note that the guide is not compatible with Xbox devices at this time.