An A320 Captain reports a Maintenance oversight; where a missing section of rubber seal between the right wing root fuselage body fairing and leading edge slat was deferred under a Slat Seal MEL. Maintenance admitted the damaged seal was a common misdiagnosed problem and spare seals were limited. No MEL exists for the the left or right Fairing Installation Wing Seal.

Narrative

This ASRS Report is designed to document and alert Maintenance about an oversight in the A320 MEL that I recently encountered. The Maintenance issue was eventually resolved; but only after much confusion; a near-illegal dispatch; and an attempt to defer the write-up with the incorrect MEL. Once resolved by Maintenance; I became aware that this is undoubtedly a common mistake - a misdiagnosed write-up that has the potential to ground the Airbus fleet.On walk around inspection; we noticed a 5' section of rubber seal missing on the right wing root between the slat and fuselage. Initial Maintenance response was to defer; since they were referencing an MEL for slat seals. Because my Co-pilot had seen this issue previously and it had resulted in an illegal dispatch weeks prior; we insisted that the slat seal MEL did not apply to this specific seal; since it is attached to the fuselage and does not travel with the slats. After a maintenance test; this fact was confirmed. Since this seal does not fall within the general MEL outlining deferral of slat seals; a new search was initiated for an MEL addressing this specific seal. It is actually called a Fairing Installation Wing Seal. No such MEL exists! My concern is that we have many A320's in the fleet; flying around with a few inches of rubber missing; with the incorrect MEL applied. Maintenance admitted that it was news to them; a common misdiagnosed problem; and that the actual spare replacements seals are limited. They said engineering would have to initiate a new MEL item and I just wanted to do my part in order to insure that the ball is rolling to address this problem.