Narrative:

While on descent to philadelphia (phl approach) we were cleared to cross bunts intersection at 8;000 ft. Flight conditions were smooth air; 10 miles visibility and clear. While descending through 11;000 ft the aircraft entered a severe upset state; full scale brick (yaw) deflection; and the aircraft rolled 30+ degree bank to the left and to the right. I disconnected the autopilot and attempted to maintain control with the hand wheel (yoke); and let the yaw damper straighten out the rudder. The yaw damper would not keep the aircraft straight and for a moment I thought we had experienced an 'uncommanded yaw motion' and asked for pilot not flying to disconnect the yaw damper but then corrected myself and kept it engaged. We exited the upset and regained aircraft control and leveled at 11;000 ft. At this time we queried ATC as to what type of aircraft was approximately 8-10 miles ahead and below us. ATC responded that it was a heavy md-11. At the time of upset; the aircraft was 700 ft below us and around 8 miles ahead of us. We reported to ATC that we had entered an upset possibly due to the md-11's wake. ATC replied; 'roger; we are complying with published separation standards; but you are the second aircraft to complain about his wake.' ATC then took us off our arrival (turned 20 degrees left) and descended us lower to avoid the md-11. We contacted the flight attendant to insure she was ok. She was fine; but was out of her seat during the event accomplishing normal approach duties. We then landed without incident. I'm calling into question the FAA's current published wake turbulence separation standards for heavy aircraft. ATC was complying with published regulations; however; our aircraft still entered a severe upset.

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Original NASA ASRS Text

Title: CRJ-200 Captain reported loss of control because of wake turbulence from a preceding MD-11 on approach to PHL. Reporter questioned current wake turbulence separation standards.

Narrative: While on descent to Philadelphia (PHL Approach) we were cleared to cross BUNTS Intersection at 8;000 FT. Flight conditions were smooth air; 10 miles visibility and clear. While descending through 11;000 FT the aircraft entered a severe upset state; full scale brick (yaw) deflection; and the aircraft rolled 30+ degree bank to the left and to the right. I disconnected the autopilot and attempted to maintain control with the hand wheel (yoke); and let the yaw damper straighten out the rudder. The yaw damper would not keep the aircraft straight and for a moment I thought we had experienced an 'uncommanded yaw motion' and asked for pilot not flying to disconnect the yaw damper but then corrected myself and kept it engaged. We exited the upset and regained aircraft control and leveled at 11;000 FT. At this time we queried ATC as to what type of aircraft was approximately 8-10 miles ahead and below us. ATC responded that it was a heavy MD-11. At the time of upset; the aircraft was 700 FT below us and around 8 miles ahead of us. We reported to ATC that we had entered an upset possibly due to the MD-11's wake. ATC replied; 'Roger; we are complying with published separation standards; but you are the second aircraft to complain about his wake.' ATC then took us off our arrival (turned 20 degrees left) and descended us lower to avoid the MD-11. We contacted the Flight Attendant to insure she was ok. She was fine; but was out of her seat during the event accomplishing normal approach duties. We then landed without incident. I'm calling into question the FAA's current published wake turbulence separation standards for heavy aircraft. ATC was complying with published regulations; however; our aircraft still entered a severe upset.

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.