Narrative:

Prior to flight out of a high altitude airport in mountainous terrain; we received performance data that indicated a flaps 15; bleeds off takeoff. This is a very uncommon takeoff configuration and would be my first in the left seat. During pushback; I noticed some weather to the north of the field; but my view was blocked by numerous aircraft parked to the north of my aircraft. We then taxied south; thus further inhibiting my view of the weather in the area. Once cleared for takeoff; I asked the first officer to turn the radar on and tilt it to a high setting so we could get a radar picture of the weather to the south. Once I turned onto the runway; I immediately noticed the weather was much more severe than I had anticipated and knew we were going to be unable to fly the published departure procedure completely. Upon reaching the flap retraction altitude; I ran the after takeoff flow; but was unable to read the checklist because I was distracted by the first officer's request for a heading. I instructed him to increase our rate of climb to allow us to clear terrain as quickly as possible so ATC could vector us to the east of the weather. I had previously changed frequencies from the tower to center but was unable to speak with the controller due to frequency congestion. At this time we were beginning to get very close to the weather which was painting reds and magentas on the radar. Once able to speak with the controller; I requested a turn to the east off the departure. The controller stated he would be unable to due so unless we were able to provide our own terrain and obstruction clearance. The departure did allow for a VMC climb on course; but our company procedure predicated staying on the departure until we reached a fix that was well within the heavy thunderstorm cell. However; I felt the safest course of action was to make the early turn in what was essentially VMC conditions and climb away from the weather. I accepted responsibility for terrain clearance and we made a right turn away from the weather towards an area of clear skies. At about this time; I heard the master warning chimes and looked up at the warning lights where I noticed the cabin press light was illuminated. I then looked up at the bleed air system panel and noticed both bleeds were still turned off. I reached up and turned both bleeds on and the system to norm; which is our normal setting for flight. The cabin then leveled out at just below 10;000 ft but did not descend. I instructed the first officer to maintain altitude; which was not at about 13;500 ft while I ran the appropriate QRH. While running the QRH; I was lead to a section that instructed the use of the manual mode. When I selected manual mode; I first accidentally decreased the differential slightly then selected 'inc diff' and the cabin descended abruptly at approximately 3;000 FPM. I then reselected 'dec diff' and reduced the decent to approximately 500 FPM. The cabin press warning light immediately turned off once the cabin began descending. At this point the QRH was complete. We were flying over mountainous terrain and I knew we were prohibited from continuing in manual mode. When I selected the system back to automatic; it climbed back up to just under 10;000 ft and the cabin press light reilluminated. I then decided to return to our departure airport for maintenance. I asked ATC for a return; but did not declare an emergency because there was no immediate threat. I quickly briefed the flight attendants; made a short announcement to the passengers; ran the appropriate checklists; and configured the aircraft and FMS for was to be a normal landing. Looking back I feel that I could improve a few areas of my performance. Because this was my first bleeds off takeoff in the left seat; I was not used to scanning that portion of the overhead panel during my after takeoff flow; this will immediately change. Also; I allowed the first officer to distract me from my duties. I could have run the after takeoff checklist while waiting to contact ATC. In the future; I plan on ensuring the checklist is complete as soon as possible during the initial climb. Furthermore; I should have taken the weather into account prior to takeoff. This incident has shown me the importance of listening to my gut and using the resources available to me; such as tower; to plan an alternate course of action or delay the flight. It was a huge learning experience; emphasized some very important areas; and I am a better captain because of it.

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Original NASA ASRS Text

Title: A new DHC-8 Captain; performing his first bleeds off takeoff from a high altitude airport; failed to turn them back on in a timely fashion. Pressurization anomalies arise directing a return to the departure airport for maintenance.

Narrative: Prior to flight out of a high altitude airport in mountainous terrain; we received performance data that indicated a Flaps 15; bleeds off takeoff. This is a very uncommon takeoff configuration and would be my first in the left seat. During pushback; I noticed some weather to the north of the field; but my view was blocked by numerous aircraft parked to the north of my aircraft. We then taxied south; thus further inhibiting my view of the weather in the area. Once cleared for takeoff; I asked the First Officer to turn the radar on and tilt it to a high setting so we could get a radar picture of the weather to the south. Once I turned onto the runway; I immediately noticed the weather was much more severe than I had anticipated and knew we were going to be unable to fly the published departure procedure completely. Upon reaching the flap retraction altitude; I ran the after takeoff flow; but was unable to read the checklist because I was distracted by the First Officer's request for a heading. I instructed him to increase our rate of climb to allow us to clear terrain as quickly as possible so ATC could vector us to the east of the weather. I had previously changed frequencies from the Tower to Center but was unable to speak with the controller due to frequency congestion. At this time we were beginning to get very close to the weather which was painting reds and magentas on the radar. Once able to speak with the Controller; I requested a turn to the east off the departure. The Controller stated he would be unable to due so unless we were able to provide our own terrain and obstruction clearance. The departure did allow for a VMC climb on course; but our company procedure predicated staying on the departure until we reached a fix that was well within the heavy thunderstorm cell. However; I felt the safest course of action was to make the early turn in what was essentially VMC conditions and climb away from the weather. I accepted responsibility for terrain clearance and we made a right turn away from the weather towards an area of clear skies. At about this time; I heard the master warning chimes and looked up at the warning lights where I noticed the Cabin Press light was illuminated. I then looked up at the bleed air system panel and noticed both bleeds were still turned off. I reached up and turned both bleeds on and the system to NORM; which is our normal setting for flight. The cabin then leveled out at just below 10;000 FT but did not descend. I instructed the First Officer to maintain altitude; which was not at about 13;500 FT while I ran the appropriate QRH. While running the QRH; I was lead to a section that instructed the use of the manual mode. When I selected manual mode; I first accidentally decreased the differential slightly then selected 'Inc Diff' and the cabin descended abruptly at approximately 3;000 FPM. I then reselected 'Dec Diff' and reduced the decent to approximately 500 FPM. The cabin press warning light immediately turned off once the cabin began descending. At this point the QRH was complete. We were flying over mountainous terrain and I knew we were prohibited from continuing in manual mode. When I selected the system back to AUTO; it climbed back up to just under 10;000 FT and the cabin press light reilluminated. I then decided to return to our departure airport for maintenance. I asked ATC for a return; but did not declare an emergency because there was no immediate threat. I quickly briefed the flight attendants; made a short announcement to the passengers; ran the appropriate checklists; and configured the aircraft and FMS for was to be a normal landing. Looking back I feel that I could improve a few areas of my performance. Because this was my first bleeds off takeoff in the left seat; I was not used to scanning that portion of the overhead panel during my after takeoff flow; this will immediately change. Also; I allowed the First Officer to distract me from my duties. I could have run the after takeoff checklist while waiting to contact ATC. In the future; I plan on ensuring the checklist is complete as soon as possible during the initial climb. Furthermore; I should have taken the weather into account prior to takeoff. This incident has shown me the importance of listening to my gut and using the resources available to me; such as tower; to plan an alternate course of action or delay the flight. It was a HUGE learning experience; emphasized some very important areas; and I am a better Captain because of it.

Data retrieved from NASA's ASRS site as of April 2012 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.