Priority between parties
The registration of an International Interest is not necessary to protect
the creditor against its own debtor. The debtor will be aware of its obligation
and therefore does not need to be “notified” by the International Registry. A
lessee for example can not claim priority over its own lessor even if it did not
register the lease with the International Registry. However, if the lessee
leases the aircraft object to a sub-lessee, and the sub-lease is registered prior
to the head-lease, the sub-lessee will have priority over the head-lessor.