Written by: Andrew Ross and Richard Swindell
Welcome back to Grey Matter and a continuing discussion on wake turbulence. Last month we addressed the categories of aircraft and wake generation along with the callsigns associated with them – heavy and super. These designations are used on frequency to alert pilots and controllers to be cautious and to call attention to the fact that aircraft in their airspace can generate flight path upsetting wake. This month, we’re focusing on active measures pilots can take to avoid or limit encounters with wake turbulence. Honestly, this probably isn’t anything you don’t already know, so instead of the boring title we gave it, this article really should be called Wake Turbulence: A Practical Guide for People Who Should Already Know Better. This is because pilots CAN actively plan to and avoid wake but are often asleep at the wheel (or yoke, or side stick depending on your persuasion). Wake turbulence is not a conspiracy, it is not personal, and it is not “probably fine.” What it is though is the simple aerodynamic consequence of lift, scaled in proportion to the size, weight, and configuration of the aircraft ahead of you.
Let’s break this down by the numbers:
1. Accept the Physics: They are not negotiable
Every wing producing lift also generates counter-rotating vortices, that:
- Sink at roughly 300–500 ft. per minute
- Drift with the wind
- Intensify with weight
- Strengthen at low speed and high angle of attack
- Become particularly assertive when attached to something with four engines and a zip code
Assume ATC’s “Caution, wake turbulence…” is not a suggestion, if the aircraft ahead of you is:
- Heavy
- Slow
- Dirty
- Or an A380
2. The Above and Beyond Principle
When following traffic on approach or arrival:
- Stay at or above the preceding aircraft’s flight path
Because vortices sink, they will never climb to greet you. If you position yourself below the glide or departure path of the preceding heavy, you are essentially volunteering for an aerodynamic demonstration.
3. Rotation Strategy: Don’t rotate into the “crime scene”
On departure behind a heavy:
- Note the rotation point
- Rotate before that point if feasible
- Climb above its flight path
- Avoid drifting into its extended centerline at low altitude
If you rotate exactly where the preceding aircraft rotated and then level briefly in ground effect, you have recreated a physics experiment nobody wants.
4. Crosswind: The silent co-conspirator
A light crosswind can:
- Hold one vortex over the runway
- Move the upwind vortex off-center
- Park the downwind vortex exactly where you plan to land
When the tower indicates crosswinds for takeoff are around 5-6 knots, interpret this as:
“One vortex may be waiting for you.” This is particularly educational behind something like a Boeing 777 or Airbus 350.
5. Intersection Departures: A confidence test
Although true for everyone (but especially for our G5 and Citation friends who have a tendency to do this), if you accept or request an intersection departure behind heavy traffic:
- You have reduced your longitudinal separation
- You may be launching directly into descending vortices
- ATC separation minima are legal, not magical
Ask yourself, “Is saving 90 seconds worth an uncommanded roll at 200 feet?” If the answer is yes, at least tighten your harness and have your passengers stow their cocktails.
6. Parallel Runways: The lateral surprise
Closely spaced parallels are efficient, and they’re also an aerodynamic exchange program. Vortices can:
- Drift laterally
- Cross centerlines
- Introduce you to roll rates you did not request
If you are downwind of a heavy on the adjacent runway, assume its wake has travel plans.
7. Visual Approaches: The temptation to compress
Visual approaches encourage:
- “We’ve got them in sight.”
- “We can keep it tight.”
- “We’ll slow early.”
All admirable, but none alter vortex strength. And while I’m all about helping out ATC, their pattern is not your problem, but a flight attendant thrown across the plane will be. If you reduce spacing because it “looks fine,” you are replacing time-based separation with optimism-based separation, and optimism has poor lift-to-drag characteristics.
8. The A380 Exception (which is not an exception)
The Airbus A380 does not produce “normal heavy wake.” It produces:
- Persistent wake
- Impressive wake
- Career-reflective wake
Regulatory separation standards are increased for a reason. That reason is fluid dynamics, not bureaucracy.
9. If You Do Encounter Wake
Despite best practice, it happens. Your immediate priorities become:
- Disconnect automation, if it is fighting you
- Apply smooth, coordinated control inputs
- Avoid abrupt overcorrections
- Add power as required
- Maintain attitude and regain controlled flight
The correct response is disciplined control, not startled aerobatics.
10. Final Operational Doctrine
To avoid wake turbulence:
- Respect weight categories
- Climb faster to get above their path
- Shallow your descent: stay above their path
- Land beyond touchdown points
- Rotate early (when appropriate)
- Be cautious with crosswinds
- Decline intersection departures when prudent
- Do not compress spacing to impress anyone
- If on oceanic tracks, offset a mile or two to avoid aircraft above and ahead of you; or if not, request vectors to avoid wake conflict
Now that the numbers, with a few attached bullet points, are out of the way, a couple of other practical ways to prepare for and preferably avoid wake turbulence include:
Taking more than just a passing glance at the prevailing wind patterns on departures and arrivals and noticing where they’re changing. This will help assess the potential movement of vortices and aid with avoidance assessment.
With ADS-B and enhanced WiFi becoming more prevalent on commercial aircraft, we are able to see callsigns on our displays, and are able to monitor sites like Flightradar24 and FlightAware which can tell us who we are following or who is heading our way. This is of course useful for path planning — for take-off, approach, or enroute.
Remember, wake turbulence is invisible, patient, and indifferent to your seniority number.
We hope you found this useful, and we will see you next month when we return to a topic mentioned last month — equal transit theory.
