A Q400 main cabin door developed a loud hissing noise and vibration at about 10;000 ft so the crew r...

Narrative:

We made the decision to return to the departure airport. As we passed through 10;000 ft the captain and I heard a loud hissing and vibrating sound that seemed to be coming from the cockpit escape hatch. The sound lasted only a few seconds and we promptly called by the flight attendants asking if they had heard the sound as well and how the passengers were doing. They told us that some of the forward passengers had heard noise and that it seemed to come from the main cabin door. At this point we had begun a descent back to 10;000 ft and slowed to 200 KTS. During the descent we checked the pressurization several times and it seemed to be holding the correct pressure. As the power was decreased for the descent and to slow down; we heard the noise again and could hear the packs surging as they adjusted for the new power setting. We referenced the QRH for the problem; but there was not a corresponding checklist. The captain then called maintenance and informed them of the situation and then called dispatch through [a commercial radio service]. The captain and dispatch collectively decided that returning to the departure airport was the best course of action. No emergency was declared [but] tower had chosen to dispatch the fire and rescue trucks as an additional precaution. We landed the aircraft without incident and returned to gate where the aircraft could be further inspected.

Original NASA ASRS Text

Title: A Q400 main cabin door developed a loud hissing noise and vibration at about 10;000 FT so the crew returned to the departure airport as a precaution although pressurization remained normal.

Narrative: We made the decision to return to the departure airport. As we passed through 10;000 FT the Captain and I heard a loud hissing and vibrating sound that seemed to be coming from the cockpit escape hatch. The sound lasted only a few seconds and we promptly called by the Flight Attendants asking if they had heard the sound as well and how the passengers were doing. They told us that some of the forward passengers had heard noise and that it seemed to come from the Main Cabin door. At this point we had begun a descent back to 10;000 FT and slowed to 200 KTS. During the descent we checked the pressurization several times and it seemed to be holding the correct pressure. As the power was decreased for the descent and to slow down; we heard the noise again and could hear the packs surging as they adjusted for the new power setting. We referenced the QRH for the problem; but there was not a corresponding checklist. The Captain then called Maintenance and informed them of the situation and then called Dispatch through [a commercial radio service]. The Captain and Dispatch collectively decided that returning to the departure airport was the best course of action. No emergency was declared [but] Tower had chosen to dispatch the fire and rescue trucks as an additional precaution. We landed the aircraft without incident and returned to gate where the aircraft could be further inspected.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	989492
Time
Date	201201
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Light	Night
Aircraft 1
Make Model Name	Dash 8-400
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	Exterior Pax/Crew Door
Person 1
Function	Pilot Flying First Officer
Qualification	Flight Crew Commercial
Person 2
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe

A Q400 main cabin door developed a loud hissing noise and vibration at about 10;000 ft so the crew returned to the departure airport as a precaution although pressurization remained normal.