Narrative:

I flew three flights on plane X which had a moderate 'wet dog/musty' smell when running the packs off of bleed 1. I didn't notice this on the 1st flight; slightly did on the second flight but quickly forgot about it because the smell was briefly limited to mid altitude descent; but no other phase of flight.on the third flight during our mid altitude descent; I realized it was a consistent smell of moderate intensity. We were below 10;000 ft. And loss of pressurization was not a concern; so I did a quick check of both bleed sources to isolate the source of the problem by quickly testing running the air conditioning (a/C) packs off bleed #2 with the cross-bleed; and by running the air conditioning packs from the #1 bleed. The smell cleared up on bleed #2; and was worse on bleed #1; so we only used the #2 bleed source for the remainder of the arrival which mitigated the smell. Afterwards; I advised maintenance and the plane was grounded for a suspected oil leak into bleed #1. We were knowingly exposed for 10-15 minutes.I have encountered this smell before (though at a higher intensity to where it was almost noxious and gave an intense headache). In the past; it was due to engine oil leaking past the seals and getting into the engine bleed air and running through the a/C pack. A factor was that earlier in the day; I had left my mobile phone on a hotel van and thus did not have easy phone access.within the 48 hours after this event; my throat has gotten scratchy; lungs felt congested (similar to inhaling a lot of wood smoke); occasionally have mild lung aching; a dry cough and more hoarse voice.threats: potential for inhalation of hazardous fumes through bleed air and/or a/C pack source; due to mechanical problemdid not use oxygen masks in response to unusual odor. Did not think to run 'air conditioning smoke' QRH (due to the fact that it was not specifically 'smoke'). This checklist probably would be the nearest fit to this scenario. Did not call supervisor immediately after event due to misplaced mobile phone.flight crew and perhaps the cabin occupants inhaled hazardous fumes from aircraft pneumatic system. Continued further flights with irritant in lungs/throat; when perhaps not fit for further flights that day.keep a tight watch on engine during maintenance and during pre-flight inspections to avoid fluid leakage into the bleed air (place greater emphasis on this during initial & recurrent training); add CO2 detectors to the flight deck for earlier warning of abnormal fumes.consider adding additional heading to 'air conditioning smoke' QRH to include 'abnormal fumes' (I did not even think to use my O2 mask as a tool for mitigation at the time); consider bleed or pack isolation; if at an appropriate altitude (which we did).flight crew should have gotten examined by medical personnel or at least spoken with supervisor immediately after event and been relieved of duty; rather than continuing further flights. This was delayed for 2 days due to operational demands over the weekend of a long/ multi-leg duty day near far 117 limits and my inability to use my misplaced mobile phone.

Related reports:

Google
 

Original NASA ASRS Text

Title: EMB-140 Captain reported a 'musty smell' during flight. Troubleshooting results reported to Maintenance on arrival.

Narrative: I flew three flights on Plane X which had a moderate 'wet dog/musty' smell when running the packs off of bleed 1. I didn't notice this on the 1st flight; slightly did on the second flight but quickly forgot about it because the smell was briefly limited to mid altitude descent; but no other phase of flight.On the third flight during our mid altitude descent; I realized it was a consistent smell of moderate intensity. We were below 10;000 ft. and loss of pressurization was not a concern; so I did a quick check of both bleed sources to isolate the source of the problem by quickly testing running the Air conditioning (A/C) packs off Bleed #2 with the cross-bleed; and by running the Air Conditioning packs from the #1 Bleed. The smell cleared up on bleed #2; and was worse on bleed #1; so we only used the #2 bleed source for the remainder of the arrival which mitigated the smell. Afterwards; I advised maintenance and the plane was grounded for a suspected oil leak into bleed #1. We were knowingly exposed for 10-15 minutes.I have encountered this smell before (though at a higher intensity to where it was almost noxious and gave an intense headache). In the past; it was due to engine oil leaking past the seals and getting into the engine bleed air and running through the A/C PACK. A factor was that earlier in the day; I had left my mobile phone on a hotel van and thus did not have easy phone access.Within the 48 hours after this event; my throat has gotten scratchy; lungs felt congested (similar to inhaling a lot of wood smoke); occasionally have mild lung aching; a dry cough and more hoarse voice.Threats: Potential for inhalation of hazardous fumes through bleed air and/or A/C PACK source; due to mechanical problemDid not use Oxygen Masks in response to unusual odor. Did not think to run 'Air Conditioning Smoke' QRH (due to the fact that it was not specifically 'Smoke'). This checklist probably would be the nearest fit to this scenario. Did not call supervisor immediately after event due to misplaced mobile phone.Flight crew and perhaps the cabin occupants inhaled hazardous fumes from Aircraft pneumatic system. Continued further flights with irritant in lungs/throat; when perhaps not fit for further flights that day.Keep a tight watch on engine during maintenance and during pre-flight inspections to avoid fluid leakage into the bleed air (place greater emphasis on this during initial & recurrent training); Add CO2 detectors to the flight deck for earlier warning of abnormal fumes.Consider adding additional heading to 'Air Conditioning Smoke' QRH to include 'Abnormal Fumes' (I did not even think to use my O2 mask as a tool for mitigation at the time); Consider Bleed or PACK isolation; if at an appropriate altitude (which we did).Flight crew should have gotten examined by medical personnel or at least spoken with supervisor immediately after event and been relieved of duty; rather than continuing further flights. This was delayed for 2 days due to operational demands over the weekend of a long/ multi-leg duty day near FAR 117 limits and my inability to use my misplaced mobile phone.

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.