Narrative:

At FL390 the aircraft had a left bleed air duct master warning. The captain said 'cancel; and identify; I have the controls and radios; reference the QRH for bleed air duct warning'. The captain asked for a lower altitude of FL240; initially since we were flying on only one operative pack. The first officer referenced the QRH and completed the checklist. The captain stated that he has had this scenario before; and stated that the other bleed air valve will close; we are going to be without pressurization. The flight crew both then donned our quick donning oxygen masks; in anticipation of losing both packs. The first officer continued the QRH checklist; and the captain then [advised] ATC and requested to descend down to 10;000 ft. Initially we were assigned a lower altitude of FL240; but the captain requested 10;000 ft. We initiated an [expedited] descent down to FL240; then were given clearance down to 10;000 ft.; and about that time we lost both packs and pressurization in the aircraft was lost. Soon after we received a cabin altitude warning message and the oxygen masks were deployed in the cabin. We continued down with the descent and completed the checklists. Once arriving at 10;000 ft. We contacted dispatch and all agreed to continue on to [destination] as planed at a cruising altitude of 10;000 ft. Before making the decision to continue; we reviewed and calculated all of our performance and fuel calculation; and deemed it was safe to continue on. We landed with 3100 pounds of fuel onboard. We then contacted dispatch and maintenance control and wrote up the aircraft.the [manual] should have a procedure where the bleeds are switched on to the operative side as soon as possible manually; to help prevent the working bleed valve from closing. This will help you by still giving you at least one operative pack so the chance of diverting are less; since we are able to operate with one pack at FL250.

Related reports:

Google
 

Original NASA ASRS Text

Title: CRJ-900 First Officer reported receiving a Left Bleed Air Duct master caution; followed by loss of both packs. An expedited descent was executed; and the flight continued to destination.

Narrative: At FL390 the aircraft had a Left Bleed Air Duct Master Warning. The Captain said 'Cancel; and Identify; I have the Controls and Radios; Reference the QRH for Bleed Air Duct Warning'. The Captain asked for a lower altitude of FL240; initially since we were flying on only one operative Pack. The First Officer referenced the QRH and completed the checklist. The Captain stated that he has had this scenario before; and stated that the other Bleed Air valve will close; we are going to be without pressurization. The flight crew both then donned our quick donning oxygen masks; in anticipation of losing both packs. The First Officer continued the QRH checklist; and the Captain then [advised] ATC and requested to descend down to 10;000 ft. Initially we were assigned a lower altitude of FL240; but the Captain requested 10;000 ft. We initiated an [expedited] descent down to FL240; then were given clearance down to 10;000 ft.; and about that time we lost both packs and pressurization in the aircraft was lost. Soon after we received a Cabin Altitude Warning Message and the oxygen masks were deployed in the cabin. We continued down with the descent and completed the checklists. Once arriving at 10;000 ft. we contacted Dispatch and all agreed to continue on to [destination] as planed at a cruising altitude of 10;000 ft. Before making the decision to continue; we reviewed and calculated all of our performance and fuel calculation; and deemed it was safe to continue on. We landed with 3100 LBS of fuel onboard. We then contacted Dispatch and Maintenance control and wrote up the aircraft.The [manual] should have a procedure where the bleeds are switched on to the operative side as soon as possible manually; to help prevent the working bleed valve from closing. This will help you by still giving you at least one operative pack so the chance of diverting are less; since we are able to operate with one pack at FL250.

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.