Narrative:

Back story; flight to ZZZ. Pack 2 deferred so it was a 3 hour haul at FL300. Uneventful the entire flight. Severe clear night in ZZZ. Going through 7000; I'm cleared for the visual. So I disengage auto pilot and throttles and hand fly the approach. Not too long after we start the approach; we start hearing a groaning noise. Like the noise you hear when you first extend the flaps. But we hadn't selected any flaps yet. The noise gets louder with a rubbing noise. I observe the EICAS looking for any kind of abnormal indication; but there's none. All systems show green and normal. The noise becomes a grinding noise. Along with a smell of burnt rubber. I'm hand flying the aircraft and I'm thankful I have the runway right in front of me and I'm on the final approach. I delay configuring the aircraft as I want a touch of extra speed to get the aircraft on the ground in case something worse is happening that we're not fully aware of. The fas call up at this time saying they heard a bang at first; plus they smell the burnt rubber and it has them worried. I ask if there's smoke yet and they say no. I tell them hang tight we're five minutes from touchdown. They also relay the passengers have a worried look on them. I tell them if anything gets worse than what they are experiencing right now to call me back as soon as possible. It's at this point I realize I'm seconds away from declaring an emergency if the situation gets any worse and we may need to evacuate. But it never got to that point. Nothing abnormal comes across the EICAS. We start configuring the aircraft for landing and the sound goes away along with the smell. We land and as we're taxing to the gate the first officer starts the APU. When it comes online we get a pack 1 fail message now. So we shut down and I go with the first officer on the walk around. Part of us is thinking we might have ate a bird. But there's no sign of anything. No damage; no sign of anything abnormal. I call maintenance control and describe everything to him. He thinks it was pack 1 failing and breaking itself apart. Thankfully; this happened while on a visual approach; and not up at cruise at FL300. At the end of the evening as I replayed those short moments over in my mind; I'm still going back and forth if putting on the masks would've been warranted. While the fume/odor was a burnt rubber smell and wasn't causing any discomfort; the potential was there that it could've been and I wouldn't have had any time to react. I was hand flying the aircraft and my focus was just getting on the aircraft landed safely and handle any further emergencies as they come. An idea in my mind was perhaps I should've instructed my first officer to put on their mask in case something would happen further and they would be able to recover the aircraft. It all happened quickly and was over as quickly as it began.

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Original NASA ASRS Text

Title: EMB-175 flight crew was dispatched with the right pack deferred. During approach the left pack began to fail and started making a grinding noise with a burnt rubber smell; but no EICAS messages. After landing and starting the APU; a pack one fail message was displayed.

Narrative: Back story; flight to ZZZ. Pack 2 deferred so it was a 3 hour haul at FL300. Uneventful the entire flight. Severe clear night in ZZZ. Going through 7000; I'm cleared for the visual. So I disengage auto pilot and throttles and hand fly the approach. Not too long after we start the approach; we start hearing a groaning noise. Like the noise you hear when you first extend the flaps. But we hadn't selected any flaps yet. The noise gets louder with a rubbing noise. I observe the EICAS looking for any kind of abnormal indication; but there's none. All systems show green and normal. The noise becomes a grinding noise. Along with a smell of burnt rubber. I'm hand flying the aircraft and I'm thankful I have the runway right in front of me and I'm on the final approach. I delay configuring the aircraft as I want a touch of extra speed to get the aircraft on the ground in case something worse is happening that we're not fully aware of. The FAs call up at this time saying they heard a bang at first; plus they smell the burnt rubber and it has them worried. I ask if there's smoke yet and they say no. I tell them hang tight we're five minutes from touchdown. They also relay the passengers have a worried look on them. I tell them if anything gets worse than what they are experiencing right now to call me back ASAP. It's at this point I realize I'm seconds away from declaring an emergency if the situation gets any worse and we may need to evacuate. But it never got to that point. Nothing abnormal comes across the EICAS. We start configuring the aircraft for landing and the sound goes away along with the smell. We land and as we're taxing to the gate the FO starts the APU. When it comes online we get a pack 1 fail message now. So we shut down and I go with the FO on the walk around. Part of us is thinking we might have ate a bird. But there's no sign of anything. No damage; no sign of anything abnormal. I call Maintenance control and describe everything to him. He thinks it was Pack 1 failing and breaking itself apart. Thankfully; this happened while on a visual approach; and not up at cruise at FL300. At the end of the evening as I replayed those short moments over in my mind; I'm still going back and forth if putting on the masks would've been warranted. While the fume/odor was a burnt rubber smell and wasn't causing any discomfort; the potential was there that it could've been and I wouldn't have had any time to react. I was hand flying the aircraft and my focus was just getting on the aircraft landed safely and handle any further emergencies as they come. An idea in my mind was perhaps I should've instructed my FO to put on their mask in case something would happen further and they would be able to recover the aircraft. It all happened quickly and was over as quickly as it began.

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.