Wake hazards explained
The hazards of wake turbulence are most pronounced when aircraft follow the same track,flying in-trail closely spaced. This happens typically when aircraft are approaching the runway or taking off from the same runway, with an aircraft of greater mass in the lead:
- In a wake turbulence encounter, sudden un-commanded roll movement may occur and in extreme cases this may be beyond the power of the controls to counteract or for the crew to respond adequately
- Autopilot disconnect may be the result and a loss of control near the ground may result in an accident
- Even if no accident happens, the cabin crew may be injured if they are not yet secured for landing
- Wake turbulence encounters can also happen en-route, though in such cases the risk of injury for unsecured passengers and cabin crew is the most significant one.
In the videos below are shown two runs of the WISA campaign, where the C550 (a light category aircraft) encounters on approach a wake turbulence. The first video shows an encounter for RMC of 0.6, which is the maximum acceptable severity defined by the new wake separations scheme for aircraft belonging to this catregory.
In the second video the same aircraft performs another encounter for a RMC of 0.8, this is what we consider not acceptable in terms of severity.