AIM ¶ 4-6-7 — RVSM Wake Turbulence
AIM 4-6-7 wake turbulence guidance for RVSM operations: when to expect encounters, mitigation options, and lateral offset rules for pilot students.
AIM 4-6-7 provides guidance on wake turbulence in RVSM (Reduced Vertical Separation Minimum) airspace, where aircraft are separated by only 1,000 feet vertically between FL290 and FL410. Operational experience — both in the U.S. and Europe — has shown wake encounters in RVSM are typically moderate or less, similar to moderate clear-air turbulence, and have not been a significant safety issue.
When to be alert for wake turbulence:
- Near aircraft climbing or descending through your altitude
- About 10–30 miles after passing 1,000 ft below opposite-direction traffic
- About 10–30 miles behind and 1,000 ft below same-direction traffic
Mitigation options if you encounter or expect wake turbulence in DRVSM airspace:
- Request a vector
- Request a flight level change
- If capable, request a lateral offset (about a wingspan upwind is usually enough to clear the vortex)
In domestic U.S. airspace, pilots must request ATC clearance before flying a lateral offset. Oceanic strategic lateral offsets do not apply here. This is recommended FAA guidance, not a regulatory requirement, but it's important checkride knowledge for high-altitude operations.