Narrative:

During climb-out at about 15;000 ft.; a flight attendant from the aft cabin called to report that the 4R door had a very loud whistling/squealing sound; like an air leak. They had just flown the aircraft in and it did not sound that way for that leg. I could hear it clearly through the intercom. We checked the pressurization system; it was working fine. We leveled off early and called dispatch who initiated a phone patch with maintenance. Due to weather approaching the field; and the potential need for customs; we all agreed that the best course of action was to divert to sju and perform an overweight landing. The first officer and I briefed threats; the descent and approach; along with the overweight landing considerations. We did not [request priority handling]. The landing was soft and uneventful. I wrote up the air leak issue and the overweight landing in the [logbook]. Maintenance pulled the landing data and signed off the jet for the overweight landing; no inspection required. After speaking with dispatch on the ground we discovered that we should have [requested priority handling] which we missed as part of the brief. There was a time element involved due to impending weather at the field. After the call with dispatch/maintenance; briefing the passengers and crew; then briefing and programming the approach we received a runway change due to a wind shift. Overall everything went well and it was a safe operation; but we needed to be more aware of the details in the QRH that were missed due to the timing of the events and our oversight. I spoke with a member of the estimated return to service the afternoon after this incident. That was the earliest I could contact someone due to the ferry flight we were assigned the next morning and the deadhead home.

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Original NASA ASRS Text

Title: A321 flight crew reported reported a whistling noise from the R4 door; causing a diversion.

Narrative: During climb-out at about 15;000 ft.; a Flight Attendant from the aft cabin called to report that the 4R door had a very loud whistling/squealing sound; like an air leak. They had just flown the aircraft in and it did not sound that way for that leg. I could hear it clearly through the intercom. We checked the pressurization system; it was working fine. We leveled off early and called Dispatch who initiated a phone patch with Maintenance. Due to weather approaching the field; and the potential need for customs; we all agreed that the best course of action was to divert to SJU and perform an overweight landing. The First Officer and I briefed threats; the descent and approach; along with the overweight landing considerations. We did not [Request Priority Handling]. The landing was soft and uneventful. I wrote up the air leak issue and the overweight landing in the [Logbook]. Maintenance pulled the landing data and signed off the jet for the overweight landing; no inspection required. After speaking with Dispatch on the ground we discovered that we should have [Requested Priority Handling] which we missed as part of the brief. There was a time element involved due to impending weather at the field. After the call with Dispatch/Maintenance; briefing the passengers and crew; then briefing and programming the approach we received a runway change due to a wind shift. Overall everything went well and it was a safe operation; but we needed to be more aware of the details in the QRH that were missed due to the timing of the events and our oversight. I spoke with a member of the Estimated Return to Service the afternoon after this incident. That was the earliest I could contact someone due to the ferry flight we were assigned the next morning and the deadhead home.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.