Narrative:

We had just leveled off at FL220 about 30 seconds before and suddenly there was a loud pop followed by an incredibly loud whistling noise from the first officer (first officer) side window area. There was no substantial pressure change; however; the noise made it incredibly hard to communicate to each other. We assumed it was his window and the first officer donned his mask followed immediately after by me. I took the radios as the first officer begin the memory action items for an emergency descent. Though we weren't currently in a pressure loss situation; we felt that it would be prudent to get low quickly in case something worse occurred and we still weren't entirely sure what was happening other than a lot of noise from the window area.though we did not do a maximum rate emergency descent; we used the emergency descent memory items and checklist to back up what we were doing. I informed center that we had what we think was a pilot window seal blow out and needed lower immediately. They gave us 10;000 and we initiated the descent. We used the cabin emergency button to call the flight attendant (flight attendant); but he had the cart out and it took about 30 seconds for him to be able to maneuver the cart to get to the phone. When he answered; it was very hard to hear him due to the cockpit noise. I informed him that we have initiated a rapid descent due to a window seal blowing out; 'we are on 02' but the cabin did not depressurize. We are going to 10;000 feet and I will call you back when we get there. Upon later speaking with the flight attendant he informed me that he heard me say 'get on 02' instead of what I said which was 'we are on 02.' this lead to his decision to use a crew bottle for himself and to manually deploy the passenger masks. Though this was a miscommunication; it was the prudent decision for him to make if there was any question is his mind that I commanded o2 or not. We completed the memory action for the emergency descent; backed it up with the qrc; and QRH and proceeded to 10;000 feet.we did slow from 250 to about 225 in an attempt to quite the cockpit noise so we could better communicate. This had little effect on the noise. At 10;000 feet we slowed to 200 knots and retracted the landing gear and removed our masks. I called the flight attendant back to inform him in more detail what had happened and to let him know we were at 10;000 feet. That is when he told me he deployed the masks manually. I assumed this was because he heard us on O2 initially instead of the miscommunication that actually happened. I let him know that everyone could come off O2 and I would make a PA in a moment. The following PA informed the passengers that we had an issue with the window seal which prompted the rapid descent. We were now safely at 10;000 feet and everything; aside from the loud noise that could be heard; was normal. We let them know that we are working on a plan on where to go and would get back with them as soon as we had one.we also communicated with dispatch via the ACARS. They were very quick to respond with weather info and acknowledging our issue. It worked great to be able to communicate with them this way as it allowed us to read and respond when we were able opposed to being on a direct communications line with them and having a conversation. I thought this was a great tool as we were already struggling with speaking over the noise. We elected to depressurize the airplane at 10;000 feet in an attempt to quiet the noise down; regain our ability to communicate effectively and think more clearly and to remove any danger of a rapid decompression. There wasn't a clear checklist for what was occurring as we hadn't lost pressurization and aside from the incredible noise we were ops normal. We elected to use the 'cracked window' checklist in the QRH as this led us to manually depressurize the airplane without having to 'dump' the cabin. Manual depressurization is the preferred method per the QRH if there isn't a specific method listed and this checklist had those steps laid out for us. This manual depressurization worked extremely well and the cabin rate begin to climb at about 700 fpm. With every minute it got quieter and we were able to begin to discuss ideas more clearly. At this time we had continued to fly on the route. This allowed us a good diversion airport if we elected. We once again spoke with the flight attendant to check on the passengers and make sure they were ok. He informed us that everyone was fine; no one was panicking; and that things were well under his control in the back. Once the cabin diff reached about 1; it become easy to communicate with each other. We discussed our options to divert or continue. The decision was made to continue to [our destination] because we were comfortable with the pressure off the seal; and because we were depressurized at 10;000 feet we wanted to make a slow 500fpm descent. In doing this descent it would take us approximately 20 min to descend and we were about 18 from [our destination]. We informed the dispatchers off this decision and they agreed that if we felt safety of flight was not at risk that we could continue. We requested EMS meet the airplane in case a passenger did have a medical issue related to the event. We briefed the flight attendant that we would be landing in 15 min and to prepare the cabin for a normal landing. We then completed a PA to inform the passengers that once again; everything was normal on the airplane; the descent was a precaution; and that we were going to continue for a normal landing. From that point on we continued a slow 500 fpm descent for passenger comfort to the airport. Aside from that; everything was done normally to include checklist and a flaps 45 landing. Once we parked and completed the shutdown check; we exited the cockpit to check on the passengers and speak with the EMS. Everyone appeared to be fine and we waited outside as they deplaned. The passengers that got off did not appear to be in any distress and everything was normal except for a few people thanking us a little more than normal. Communication was tough for us over the noise and it made for a more confusing and challenging situation than the sim accurately depicts. With that said the crew did a good job attempting to communicate to each other; the passengers and ATC and in the absence of clearly understood direction; the safest course of action was chosen by all of the flight crew.the incredible noise was very surprising to me. It became difficult to communicate to each other; ATC; and the flight attendant and that led to flight attendant dropping masks in the cabin. I would have preferred the masks were not dropped; however; the flight attendant did what he thought was the safest course of action and I support that decision fully. It was a great learning experience to speak with him after and find out that he heard something different than what I said; and that led to the masks being dropped. I will in the future be clearer of exactly what I need them to do. When I called about the landing I said 'this is a normal landing; we will be taxiing to the gate.' I made that clear because I didn't want him to evacuate for any reason. What I should have done when we first communicated was say 'we are in a rapid descent but we have not lost pressurization; you do not need to deploy the masks.' I think that would have conveyed clearer what I was thinking. This event was not black or white decision making. There were multiple areas that required us to develop certificate of authorization (coa) together.events like this make good training scenarios in the sim or even as discussion points. In the sim it is black or white. Rapid deco is rapid deco; but what if you think that rapid deco is a possibility? I think events like this that lead to a little more confusion or lack of ability to communicate would make good training events as it requires the crew to think outside the box of what is usually an obvious solution.

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Original NASA ASRS Text

Title: EMB-145 flight crew experienced a loud pop at FL220 followed by an incredibly loud whistling noise from the First Officer's side window. Pressurization was not lost and the crew elected to descend to 10;000 feet to depressurize and minimize the noise.

Narrative: We had just leveled off at FL220 about 30 seconds before and suddenly there was a loud pop followed by an incredibly loud whistling noise from the First Officer (FO) side window area. There was no substantial pressure change; however; the noise made it incredibly hard to communicate to each other. We assumed it was his window and the FO donned his mask followed immediately after by me. I took the radios as the FO begin the memory action items for an emergency descent. Though we weren't currently in a pressure loss situation; we felt that it would be prudent to get low quickly in case something worse occurred and we still weren't entirely sure what was happening other than a lot of noise from the window area.Though we did not do a maximum rate emergency descent; we used the emergency descent memory items and checklist to back up what we were doing. I informed Center that we had what we think was a pilot window seal blow out and needed lower immediately. They gave us 10;000 and we initiated the descent. We used the Cabin EMER button to call the Flight Attendant (FA); but he had the cart out and it took about 30 seconds for him to be able to maneuver the cart to get to the phone. When he answered; it was very hard to hear him due to the cockpit noise. I informed him that we have initiated a rapid descent due to a window seal blowing out; 'we are on 02' but the cabin did not depressurize. We are going to 10;000 feet and I will call you back when we get there. Upon later speaking with the flight attendant he informed me that he heard me say 'get on 02' instead of what I said which was 'we are on 02.' This lead to his decision to use a crew bottle for himself and to manually deploy the passenger masks. Though this was a miscommunication; it was the prudent decision for him to make if there was any question is his mind that I commanded o2 or not. We completed the memory action for the emergency descent; backed it up with the QRC; and QRH and proceeded to 10;000 feet.We did slow from 250 to about 225 in an attempt to quite the cockpit noise so we could better communicate. This had little effect on the noise. At 10;000 feet we slowed to 200 knots and retracted the landing gear and removed our masks. I called the FA back to inform him in more detail what had happened and to let him know we were at 10;000 feet. That is when he told me he deployed the masks manually. I assumed this was because he heard us on O2 initially instead of the miscommunication that actually happened. I let him know that everyone could come off O2 and I would make a PA in a moment. The following PA informed the passengers that we had an issue with the window seal which prompted the rapid descent. We were now safely at 10;000 feet and everything; aside from the loud noise that could be heard; was normal. We let them know that we are working on a plan on where to go and would get back with them as soon as we had one.We also communicated with dispatch via the ACARS. They were very quick to respond with weather info and acknowledging our issue. It worked great to be able to communicate with them this way as it allowed us to read and respond when we were able opposed to being on a direct communications line with them and having a conversation. I thought this was a great tool as we were already struggling with speaking over the noise. We elected to depressurize the airplane at 10;000 feet in an attempt to quiet the noise down; regain our ability to communicate effectively and think more clearly and to remove any danger of a rapid decompression. There wasn't a clear checklist for what was occurring as we hadn't lost pressurization and aside from the incredible noise we were ops normal. We elected to use the 'Cracked Window' checklist in the QRH as this led us to manually depressurize the airplane without having to 'Dump' the cabin. Manual depressurization is the preferred method per the QRH if there isn't a specific method listed and this checklist had those steps laid out for us. This manual depressurization worked extremely well and the cabin rate begin to climb at about 700 fpm. With every minute it got quieter and we were able to begin to discuss ideas more clearly. At this time we had continued to fly on the route. This allowed us a good diversion airport if we elected. We once again spoke with the FA to check on the passengers and make sure they were ok. He informed us that everyone was fine; no one was panicking; and that things were well under his control in the back. Once the cabin diff reached about 1; it become easy to communicate with each other. We discussed our options to divert or continue. The decision was made to continue to [our destination] because we were comfortable with the pressure off the seal; and because we were depressurized at 10;000 feet we wanted to make a slow 500fpm descent. In doing this descent it would take us approximately 20 min to descend and we were about 18 from [our destination]. We informed the dispatchers off this decision and they agreed that if we felt safety of flight was not at risk that we could continue. We requested EMS meet the airplane in case a passenger did have a medical issue related to the event. We briefed the FA that we would be landing in 15 min and to prepare the cabin for a normal landing. We then completed a PA to inform the passengers that once again; everything was normal on the airplane; the descent was a precaution; and that we were going to continue for a normal landing. From that point on we continued a slow 500 fpm descent for passenger comfort to the airport. Aside from that; everything was done normally to include checklist and a flaps 45 landing. Once we parked and completed the shutdown check; we exited the cockpit to check on the passengers and speak with the EMS. Everyone appeared to be fine and we waited outside as they deplaned. The passengers that got off did not appear to be in any distress and everything was normal except for a few people thanking us a little more than normal. Communication was tough for us over the noise and it made for a more confusing and challenging situation than the sim accurately depicts. With that said the crew did a good job attempting to communicate to each other; the passengers and ATC and in the absence of clearly understood direction; the safest course of action was chosen by all of the flight crew.The incredible noise was very surprising to me. It became difficult to communicate to each other; ATC; and the FA and that led to FA dropping masks in the cabin. I would have preferred the masks were not dropped; however; the FA did what he thought was the safest course of action and I support that decision fully. It was a great learning experience to speak with him after and find out that he heard something different than what I said; and that led to the masks being dropped. I will in the future be clearer of exactly what I need them to do. When I called about the landing I said 'this is a normal landing; we will be taxiing to the gate.' I made that clear because I didn't want him to evacuate for any reason. What I should have done when we first communicated was say 'we are in a rapid descent but we have not lost pressurization; you do not need to deploy the masks.' I think that would have conveyed clearer what I was thinking. This event was not black or white decision making. There were multiple areas that required us to develop Certificate of Authorization (COA) together.Events like this make good training scenarios in the sim or even as discussion points. In the sim it is black or white. Rapid Deco is rapid deco; but what if you think that rapid deco is a possibility? I think events like this that lead to a little more confusion or lack of ability to communicate would make good training events as it requires the crew to think outside the box of what is usually an obvious solution.

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.