Can't seem to upgrade Jap naval airunits to Jack fighters

[Japanese Ace]

For some reason, even though I have been able to build "Jack" japaenese naval fighter from 4/43 in the replacement que none of my exisiting jap naval fighters show that as part of my upgrade, any hints as to why that may be?

[n01487477]

ORIGINAL: Japanese Ace

For some reason, even though I have been able to build "Jack" japaenese naval fighter from 4/43 in the replacement que none of my exisiting jap naval fighters show that as part of my upgrade, any hints as to why that may be?

Not many people use them, most prefer the George. They are upgradeable but depending on whether you're using the beta or not you'll need to change their type to non-cv first (A6M3). With the beta some of this confusion has been removed and you can pay PP for the privelege [;)]

Tracker will tell you which and what can upgrade...

[Mike Solli]

If you're trying to put them on carrier based fighter daitai, that probably is your answer. They aren't carrier capable. Try putting them on land based IJN fighter daitai.