You may need to update both your contact details, related to your Membership ID (your eligibility record) and your contact details, related to your .aero domain name. The first contacts you can update here. For the second one you will need to contact your registrar directly.
Membership ID is associated with private data only viewable by yourselves, SITA and your registrar.
Registrant contact records (as well as billing, admin and tech record) are part of a public Who-is service and any third party using Internet can access this information.
As a matter of policy, registrant and Membership ID holder must be the same legal entity. Registrars are responsible for verifying the fact and may refuse to make changes if these are not consistent.
Only SITA, yourselves and third parties with whom you share the password relating to this ID can view the contents of the ID, either via the web interface on this web site or, for registrars, directly in the registry database. Registrars may for example copy your Membership ID contact to pre-fill your normal registrant contact data.