Change field to required with a condition in SAPAPO/loc3

Hello,

I want to change a field to be required in the location master data. For example in transaction /SAPAPO/loc3, under the general tab, the IATA code field should be set to required, but only if the location type is that of an airport (1110),

An alternative would be a BAdI that is executed before saving the location data, where I could insert some code.

So two questions: Is there a way to change a field of a standart SAP transaction to required under a specific condition? Is there a BAdI for the transaction SAPAPO/loc3 that would let me insert some code before saving?