Q400
Flight Crew Air Transport Pilot (ATP)
Inflight Event / Encounter Wake Vortex Encounter
General None Reported / Taken
Environment - Non Weather Related; Procedure
We encountered wake turbulence on our descent into Washington Dulles at 7;000 FT MSL and approximately 30 miles northwest of IAD. The autopilot was engaged at the time and the aircraft began to roll uncommanded. I disconnected the autopilot; arrested the roll; and slowed the aircraft towards maneuvering speed. The encounter only lasted for a matter of seconds. The bank was never greater than 30 degrees and no limitations were exceeded. The pilot not flying contacted the cabin crew and they reported that everyone was ok. The seat belt sign was on and no passengers or flight crew were injured during the encounter. The pilot not flying reported the wake turbulence event to ATC and they responded by informing us for the first time that we were following a heavy Boeing 777. I then noticed that my windscreen wiper had moved during the encounter. During a post flight inspection of the aircraft I found that the First Officer's windscreen wiper was bent. The Captain contacted Maintenance and informed them of the situation. This event occurred because of the lack of communication from ATC and possible mishandling from the Approach Controller. We were never informed that we were following a heavy B777 and the Controller descended us behind and below the B777. As a result we encountered wake turbulence. At no time was the B777 in sight.
[Inbound to] IAD; we encountered moderate to severe wake turbulence. We were on the ROYIL2 Arrival talking to Potomac Approach at an altitude of 7;000 FT. The aircraft unexpectedly banked approximately 30 degrees to the right. The First Officer; pilot flying; turned off the autopilot and recovered. I; pilot not flying; immediately scanned the PCFS to verify that we were not experiencing a flight control malfunction. During the recovery ATC issued us a descent to 6;000 FT. As soon as we started to regain control we notified ATC that we were unable to comply with the descent at this moment because we were experiencing some really bad turbulence. ATC responded with a confused sounding 'really?' and then informed us that we were behind a heavy B777. ATC needs to provide adequate space and inform us when we are behind a heavy.
Q400 flight crew reported a significant wake vortex encounter with a preceding B777 that ATC had not mentioned.