Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 50; Flight Crew Total 1305; Flight Crew Type 177
Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Wake Vortex Encounter
Air Traffic Control Provided Assistance; Flight Crew Regained Aircraft Control; Flight Crew Requested ATC Assistance / Clarification
Procedure; Environment - Non Weather Related
The purpose of this report is to give awareness of the possibility of strong wake vortex and turbulence encounter over large distances at high altitude. This is especially applicable to light and very light jets. In VFR conditions; wake turbulence was encountered from a heavy B777 at a distance of about 25 miles at an altitude of about 30;000 ft. in a BE400XP of about 14;000 lbs. at the time of the encounter. The BE400XP was within 1;000 ft. of the altitude of the heavy B777 25 miles ahead and we were climbing to a higher cruise altitude above the B777. The encounter resulted in temporary turbulence between moderate and severe and the aircraft tried to roll beyond 45-50 degrees twice with uncommanded input from an initial attitude of a wings level climb of about 1;000 fpm. No autopilot was yet engaged. The aircraft was being flown by hand (the autopilot about to be engage as we just entered RVSM airspace) and the upset recovery was immediate but required very large roll corrections to keep the aircraft upright. At the time of the encounter; the heavy B777 was ahead and to the left at about 25 miles and winds were a quartering tailwind of about 78 kts. Given the distance of separation and the amount of wind movement at that altitude; the wake vortex encounter was not expected and a complete surprise. There was no visible contrail from the B777. We thought the vortex would have dissipated well ahead of our point of encounter. Instead; it appears the vortex was strong enough to still be very significant at that distance and was blown across our route with the prevailing winds. The entire event lasted about 5-10 seconds. ATC was then notified and concurred it was most likely the wake of the heavy aircraft 25 miles ahead. Initially; both aircraft had been on a similar flight route. They also initially had closer separation and both paths had crossed at an earlier point in flight with the BE400XP below the heavy B777 flight path with no issue. At the stage of closer separation and route intersection ATC had given us an advisory of the aircraft. I am the FO (First Officer) and I was the pilot flying from the left seat. The CA (Captain) was the pilot monitoring and both of us discussed the possibility of wake vortex encounter with closer separation. We both visually identified the aircraft when in sight distance; and we were careful to avoid known problem areas relative to the B777 where wake vortex would be an issue. As the flight progressed; we moved to a relative position in trail of the heavy B777 with the distance between us and them continually increasing. Eventually we were well beyond any close separation where a wake vortex encounter is normally thought to occur. However; at about 25 miles of separation and within 1;000 ft. of the altitude of the heavy B777; we encountered strong wake vortex as we climbed to a higher altitude. No significant naturally occurring turbulence had been forecast (a large high pressure system was over this area) and none was encountered prior to or after the wake turbulence event. In addition; no other traffic was within 50 miles; this and the B777 distance were re-verified after the vortex encounter.In retrospect; I am not sure there is anything different either the flight crew or ATC could have done to avoid the wake vortex encounter. However; if I had a choice in policy design; I would recommend that all flight crews hand fly the aircraft to cruise altitude even in RVSM airspace. I realize an autopilot is an FAA requirement for operating in RVSM. In addition; many flight departments and large carriers require the autopilot to be engaged more or less right after takeoff. This policy can unintentionally degrade stick and rudder skills as a pilot needs to have a feel and understanding of actual aircraft performance. This is critical at high altitude as aircraft control is more sensitive. An autopilot is not a substitute for actual stick and rudder skills even at high altitude. (Autopilots canfail.) Upset recovery has happened in the real world at high altitude. This is an example of a well-trained; competent; and alert flight crew encountering an unusual attitude event in circumstances one would not expect the event to occur. I also question whether an autopilot would have impeded the recovery time as the 'startle effect' could be more pronounced. In addition; I think that being in RVSM airspace can give a false sense of safety as heavy aircraft are routinely on route in very close proximity to light aircraft. I see this as not only an awareness issue for flight crews but system stakeholders in general (ATC; FAA policy teams; flight departments; etc).
Reporter stated the risk of upset is great with a small jet in trail of a heavy.
BE-400 First Officer reported encountering wake turbulence climbing through FL300 25 miles in trail of a B777 that resulted in a loss of aircraft control.