Cessna Citation Sovereign (C680)
Flight Crew Air Transport Pilot (ATP)
ATC Issue All Types; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Wake Vortex Encounter
Aircraft Aircraft Damaged; Flight Crew Regained Aircraft Control
Environment - Non Weather Related; Procedure
We were being descended by ATC while on the KASPR4 arrival into MSP. We were at FL200. I noticed another aircraft in front of us both visually and on the TCAS monitor. I was surprised that we appeared to be catching up with him and getting close and also that he was above us at FL220. I believe I mentioned to my copilot that I thought they would have to start slowing us because we were getting too close to the traffic in front of us. Just then; ATC called us with holding instructions to hold as published at KASPR. I think this occurred while between Waterloo (ALO) and JAGOW. We then crossed JAGOW. I saw on the TCAS that the traffic in front of us was now descending to our altitude of FL200. We started to get some mild bumps and I think I said; 'Here comes the wake' when suddenly and violently we were thrown into a highly accelerated roll to the right. I estimate our bank angle was between 70 and 90 degrees; right wing down. I instinctively added full left aileron to counter the roll; and the aircraft returned to level. We lost approximately 1;500 FT during the upset which lasted only a few seconds. I instructed the SIC to inform ATC that we were just hit by wake turbulence. ATC instructed us to maintain FL200 and I climbed back and leveled at FL200. We had one passenger on board who was not wearing a seat belt at the time. Prior to this event we had smooth air and had not illuminated the Seat Belt sign. The passenger had been thrown about the cabin and suffered a strain to her left shoulder area. The passenger could not find her phone as it had been ejected from her hands and mixed into all the debris on the cabin floor. Out of an abundance of caution I asked ATC to have paramedics standing by for our arrival. All loose items in the cabin were strewn about and onto the floor. A table was ejected from its stowage area and broken from its hinges. A Coke that the copilot was drinking flew into the instrument panel; and the right side PFD went blank. A few minutes later I asked what type of aircraft was in front of us and was told a DC-10. I believe ATC let us get too close behind a heavy DC10; and did not alert us to the type of aircraft in front of us. They should have slowed us or provided some other type of separation to avoid the close proximity. I also believe that not only were we too close; but that it was an error to have a heavy DC10 assigned to an altitude 2;000 FT above a following light civil aircraft. This allowed the wake to descend into our altitude; especially when he was descending into our altitude so that his wake was being generated at all altitudes from 2;000 FT above us to our current altitude; providing a perfect scenario to encounter his wake; which unfortunately we did.
I don't know the spacing limits for a heavy aircraft; but it seemed to us that ATC instructing us to slow or give us a vector could have possibly avoided this situation.
CE-680 flight crew reported wake vortex encounter at FL200 from a preceding DC-10 that resulted in a violent 70-90 degree roll to the right. Their passenger suffered a slight injury as a result of the encounter.