Flight Crew Air Transport Pilot (ATP)
Deviation - Speed All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Wake Vortex Encounter
General None Reported / Taken
Procedure; Environment - Non Weather Related
Vectored on a base for the ILS 4R; we had a few 30 degree bank fluctuations due to wake turbulence. We asked whom we were following - we were behind a heavy DC10. We told them we wanted more spacing so they gave us a speed reduction of 180 KTS. We were also given a heading of 040 which put us parallel to the localizer course. I queried Approach about the heading. She said she gave us 010 to intercept; but we both had heard 040. We turned and intercepted on a 010 heading. The winds were blowing almost straight at us at 42 KTS at 2;000 FT. We were IMC; but I could see our spacing on TCAS. We had been cleared for the approach at this point and switched to Tower. The DC10 reported a speed of 150; so we slowed to our final ref speed of 145. We were about 5.5 miles behind the DC10. The Tower Controller then asked what our speed was and if we had been assigned a speed to maintain by the previous Controller. Once we had been cleared for the approach; we had not been told to maintain any particular speed to the marker; so I replied that we had not been given a speed. We were instructed to increase speed by 20 KTS. I told her we were unable due to wake turbulence. She told us we had adequate spacing of 5 miles. I replied that we had been affected by their wake and we were not going to get any closer. I felt justified to do so for safety of flight. I believe that even though we had the required spacing; the wind conditions is what caused us to experience the wake turbulence beyond the standard mileage. We continued and had no more wake disruptions for the rest of the approach or landing.
The wake turbulence put the aircraft in a undesired state by continuously experiencing severe turbulence. ATC was reluctant in handling the situation with an appropriate reaction by not providing spacing after being told of the severe wake turbulence. The crew recognized the threat after the first pocket of wake turbulence and took the appropriate actions by slowing and configuring to provide our own spacing since ATC was of no concern to our situation. We continuously monitored our TCAS to ensure we were separating from the traffic along with watching the winds at altitude to ensure we would be out of the path of the wake turbulence.
A CRJ200 experienced a wake turbulence event when vectored behind a DC10 on approach to JFK.