Visual separation questioned?

[swimer]

Hi. I wonder in one nice day if you- pilot is requested to maintain own separation in VMC what would you mind to keep wake turbulace rules? And in the controlled tower how could you know that the wake turbulance separation are not infringed, including when reduced saparation? Thank you!

[None.]

if you- pilot is requested to maintain own separation in VMC what would you mind to keep wake turbulace rules?

I personally figure the guys who came up with the mileage for controllers on wake turbulence separation probably had access to a lot of fancy data generated from a lot of fancy tests/observations. A lot more than I ever personally would, anyway. Thus, I'd still try to maintain those same distances unless I felt really comfortable about remaining above the larger aircraft's flight path.

And in the controlled tower how could you know that the wake turbulance separation are not infringed, including when reduced saparation?

Is this still in the context of visual separation? If so, and assuming the pilot accepted it (after all, it's an agreement - not an ATC command), why would you care to do so?

Sure, you can try to be helpful and clog up your frequency with reminders to the Skyhawk that he's about to get close enough to a B744 to read the serial number off his APU... but you wouldn't have to. If the Skyhawk was properly advised ("caution wake turbulence") and accepted visual separation, it's the pilot's fault if he subsequently flies into the wake and his severed wings make separate landings (without clearance, nonetheless!) ahead of the remaining fuselage.

[StuSEL]

Controllers can't use controller-applied visual separation in lieu of wake turbulence rules. If a pilot agrees to maintain visual separation or follow another aircraft, then he assumes the responsibility for wake turbulence separation.

Landing behind an equally-sized or heavier aircraft, it is best to descend above the preceding aircraft's flight path. Departing behind an equally-sized or heavier aircraft, it is best to try and climb above the preceding aircraft's flight path, which isn't always possible, hence using time or relying on a particularly strong crosswind to take care of the wake turbulence is a pilot's best bet.

More and more research is being done on the topic of wake turbulence separation. The FAA has developed something called RECAT, which is a program designed to recategorize the wake turbulence separation standards between aircraft that will be rolling out in the next few years.