Thanks for the information Ashley.
I am using the latest IOS version 11.3.1 on both of my iPad pro devices (12.9 and 9.7). I found that I can now run Construct3 offline but only when I launch Safari and then choose the Construct3 bookmark that I have created which will work while in aiplane mode.
I was not able to run Construct3 offline if launching Construct3 from the desktop icon as Construct3 suggests when first launched (Dialog to add Construct3 to desktop).
Again, thanks for the help!